#!/usr/bin/perl
# Copyright (C) 2006, Eric Wong <normalperson@yhbt.net>
# License: GPL v2 or later
use 5.008;
use warnings;
use strict;
use vars qw/    $AUTHOR $VERSION
                $sha1 $sha1_short $_revision $_repository
                $_q $_authors $_authors_prog %users/;
$AUTHOR = 'Eric Wong <normalperson@yhbt.net>';
$VERSION = '@@GIT_VERSION@@';

use Git::SVN::Utils qw(fatal can_compress);

# From which subdir have we been invoked?
my $cmd_dir_prefix = eval {
        command_oneline([qw/rev-parse --show-prefix/], STDERR => 0)
} || '';

my $git_dir_user_set = 1 if defined $ENV{GIT_DIR};
$ENV{GIT_DIR} ||= '.git';
$Git::SVN::default_repo_id = 'svn';
$Git::SVN::default_ref_id = $ENV{GIT_SVN_ID} || 'git-svn';
$Git::SVN::Ra::_log_window_size = 100;
$Git::SVN::_minimize_url = 'unset';

if (! exists $ENV{SVN_SSH} && exists $ENV{GIT_SSH}) {
        $ENV{SVN_SSH} = $ENV{GIT_SSH};
}

if (exists $ENV{SVN_SSH} && $^O eq 'msys') {
        $ENV{SVN_SSH} =~ s/\\/\\\\/g;
        $ENV{SVN_SSH} =~ s/(.*)/"$1"/;
}

$Git::SVN::Log::TZ = $ENV{TZ};
$ENV{TZ} = 'UTC';
$| = 1; # unbuffer STDOUT

# All SVN commands do it.  Otherwise we may die on SIGPIPE when the remote
# repository decides to close the connection which we expect to be kept alive.
$SIG{PIPE} = 'IGNORE';

# Given a dot separated version number, "subtract" it from
# the SVN::Core::VERSION; non-negaitive return means the SVN::Core
# is at least at the version the caller asked for.
sub compare_svn_version {
        my (@ours) = split(/\./, $SVN::Core::VERSION);
        my (@theirs) = split(/\./, $_[0]);
        my ($i, $diff);

        for ($i = 0; $i < @ours && $i < @theirs; $i++) {
                $diff = $ours[$i] - $theirs[$i];
                return $diff if ($diff);
        }
        return 1 if ($i < @ours);
        return -1 if ($i < @theirs);
        return 0;
}

sub _req_svn {
        require SVN::Core; # use()-ing this causes segfaults for me... *shrug*
        require SVN::Ra;
        require SVN::Delta;
        if (::compare_svn_version('1.1.0') < 0) {
                fatal "Need SVN::Core 1.1.0 or better (got $SVN::Core::VERSION)";
        }
}

use Carp qw/croak/;
use Digest::MD5;
use IO::File qw//;
use File::Basename qw/dirname basename/;
use File::Path qw/mkpath/;
use File::Spec;
use File::Find;
use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
use IPC::Open3;
use Git;
use Git::SVN::Editor qw//;
use Git::SVN::Fetcher qw//;
use Git::SVN::Ra qw//;
use Git::SVN::Prompt qw//;
use Memoize;  # core since 5.8.0, Jul 2002

BEGIN {
        # import functions from Git into our packages, en masse
        no strict 'refs';
        foreach (qw/command command_oneline command_noisy command_output_pipe
                    command_input_pipe command_close_pipe
                    command_bidi_pipe command_close_bidi_pipe/) {
                for my $package ( qw(Git::SVN::Migration Git::SVN::Log Git::SVN),
                        __PACKAGE__) {
                        *{"${package}::$_"} = \&{"Git::$_"};
                }
        }
        Memoize::memoize 'Git::config';
        Memoize::memoize 'Git::config_bool';
}

my ($SVN);

$sha1 = qr/[a-f\d]{40}/;
$sha1_short = qr/[a-f\d]{4,40}/;
my ($_stdin, $_help, $_edit,
        $_message, $_file, $_branch_dest,
        $_template, $_shared,
        $_version, $_fetch_all, $_no_rebase, $_fetch_parent,
        $_merge, $_strategy, $_preserve_merges, $_dry_run, $_local,
        $_prefix, $_no_checkout, $_url, $_verbose,
        $_git_format, $_commit_url, $_tag, $_merge_info, $_interactive);
$Git::SVN::_follow_parent = 1;
$Git::SVN::Fetcher::_placeholder_filename = ".gitignore";
$_q ||= 0;
my %remote_opts = ( 'username=s' => \$Git::SVN::Prompt::_username,
                    'config-dir=s' => \$Git::SVN::Ra::config_dir,
                    'no-auth-cache' => \$Git::SVN::Prompt::_no_auth_cache,
                    'ignore-paths=s' => \$Git::SVN::Fetcher::_ignore_regex,
                    'ignore-refs=s' => \$Git::SVN::Ra::_ignore_refs_regex );
my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
                'authors-file|A=s' => \$_authors,
                'authors-prog=s' => \$_authors_prog,
                'repack:i' => \$Git::SVN::_repack,
                'noMetadata' => \$Git::SVN::_no_metadata,
                'useSvmProps' => \$Git::SVN::_use_svm_props,
                'useSvnsyncProps' => \$Git::SVN::_use_svnsync_props,
                'log-window-size=i' => \$Git::SVN::Ra::_log_window_size,
                'no-checkout' => \$_no_checkout,
                'quiet|q+' => \$_q,
                'repack-flags|repack-args|repack-opts=s' =>
                   \$Git::SVN::_repack_flags,
                'use-log-author' => \$Git::SVN::_use_log_author,
                'add-author-from' => \$Git::SVN::_add_author_from,
                'localtime' => \$Git::SVN::_localtime,
                %remote_opts );

my ($_trunk, @_tags, @_branches, $_stdlayout);
my %icv;
my %init_opts = ( 'template=s' => \$_template, 'shared:s' => \$_shared,
                  'trunk|T=s' => \$_trunk, 'tags|t=s@' => \@_tags,
                  'branches|b=s@' => \@_branches, 'prefix=s' => \$_prefix,
                  'stdlayout|s' => \$_stdlayout,
                  'minimize-url|m!' => \$Git::SVN::_minimize_url,
                  'no-metadata' => sub { $icv{noMetadata} = 1 },
                  'use-svm-props' => sub { $icv{useSvmProps} = 1 },
                  'use-svnsync-props' => sub { $icv{useSvnsyncProps} = 1 },
                  'rewrite-root=s' => sub { $icv{rewriteRoot} = $_[1] },
                  'rewrite-uuid=s' => sub { $icv{rewriteUUID} = $_[1] },
                  %remote_opts );
my %cmt_opts = ( 'edit|e' => \$_edit,
                'rmdir' => \$Git::SVN::Editor::_rmdir,
                'find-copies-harder' => \$Git::SVN::Editor::_find_copies_harder,
                'l=i' => \$Git::SVN::Editor::_rename_limit,
                'copy-similarity|C=i'=> \$Git::SVN::Editor::_cp_similarity
);

my %cmd = (
        fetch => [ \&cmd_fetch, "Download new revisions from SVN",
                        { 'revision|r=s' => \$_revision,
                          'fetch-all|all' => \$_fetch_all,
                          'parent|p' => \$_fetch_parent,
                           %fc_opts } ],
        clone => [ \&cmd_clone, "Initialize and fetch revisions",
                        { 'revision|r=s' => \$_revision,
                          'preserve-empty-dirs' =>
                                \$Git::SVN::Fetcher::_preserve_empty_dirs,
                          'placeholder-filename=s' =>
                                \$Git::SVN::Fetcher::_placeholder_filename,
                           %fc_opts, %init_opts } ],
        init => [ \&cmd_init, "Initialize a repo for tracking" .
                          " (requires URL argument)",
                          \%init_opts ],
        'multi-init' => [ \&cmd_multi_init,
                          "Deprecated alias for ".
                          "'$0 init -T<trunk> -b<branches> -t<tags>'",
                          \%init_opts ],
        dcommit => [ \&cmd_dcommit,
                     'Commit several diffs to merge with upstream',
                        { 'merge|m|M' => \$_merge,
                          'strategy|s=s' => \$_strategy,
                          'verbose|v' => \$_verbose,
                          'dry-run|n' => \$_dry_run,
                          'fetch-all|all' => \$_fetch_all,
                          'commit-url=s' => \$_commit_url,
                          'revision|r=i' => \$_revision,
                          'no-rebase' => \$_no_rebase,
                          'mergeinfo=s' => \$_merge_info,
                          'interactive|i' => \$_interactive,
                        %cmt_opts, %fc_opts } ],
        branch => [ \&cmd_branch,
                    'Create a branch in the SVN repository',
                    { 'message|m=s' => \$_message,
                      'destination|d=s' => \$_branch_dest,
                      'dry-run|n' => \$_dry_run,
                      'tag|t' => \$_tag,
                      'username=s' => \$Git::SVN::Prompt::_username,
                      'commit-url=s' => \$_commit_url } ],
        tag => [ sub { $_tag = 1; cmd_branch(@_) },
                 'Create a tag in the SVN repository',
                 { 'message|m=s' => \$_message,
                   'destination|d=s' => \$_branch_dest,
                   'dry-run|n' => \$_dry_run,
                   'username=s' => \$Git::SVN::Prompt::_username,
                   'commit-url=s' => \$_commit_url } ],
        'set-tree' => [ \&cmd_set_tree,
                        "Set an SVN repository to a git tree-ish",
                        { 'stdin' => \$_stdin, %cmt_opts, %fc_opts, } ],
        'create-ignore' => [ \&cmd_create_ignore,
                             'Create a .gitignore per svn:ignore',
                             { 'revision|r=i' => \$_revision
                             } ],
        'mkdirs' => [ \&cmd_mkdirs ,
                      "recreate empty directories after a checkout",
                      { 'revision|r=i' => \$_revision } ],
        'propget' => [ \&cmd_propget,
                       'Print the value of a property on a file or directory',
                       { 'revision|r=i' => \$_revision } ],
        'proplist' => [ \&cmd_proplist,
                       'List all properties of a file or directory',
                       { 'revision|r=i' => \$_revision } ],
        'show-ignore' => [ \&cmd_show_ignore, "Show svn:ignore listings",
                        { 'revision|r=i' => \$_revision
                        } ],
        'show-externals' => [ \&cmd_show_externals, "Show svn:externals listings",
                        { 'revision|r=i' => \$_revision
                        } ],
        'multi-fetch' => [ \&cmd_multi_fetch,
                           "Deprecated alias for $0 fetch --all",
                           { 'revision|r=s' => \$_revision, %fc_opts } ],
        'migrate' => [ sub { },
                       # no-op, we automatically run this anyways,
                       'Migrate configuration/metadata/layout from
                        previous versions of git-svn',
                       { 'minimize' => \$Git::SVN::Migration::_minimize,
                         %remote_opts } ],
        'log' => [ \&Git::SVN::Log::cmd_show_log, 'Show commit logs',
                        { 'limit=i' => \$Git::SVN::Log::limit,
                          'revision|r=s' => \$_revision,
                          'verbose|v' => \$Git::SVN::Log::verbose,
                          'incremental' => \$Git::SVN::Log::incremental,
                          'oneline' => \$Git::SVN::Log::oneline,
                          'show-commit' => \$Git::SVN::Log::show_commit,
                          'non-recursive' => \$Git::SVN::Log::non_recursive,
                          'authors-file|A=s' => \$_authors,
                          'color' => \$Git::SVN::Log::color,
                          'pager=s' => \$Git::SVN::Log::pager
                        } ],
        'find-rev' => [ \&cmd_find_rev,
                        "Translate between SVN revision numbers and tree-ish",
                        {} ],
        'rebase' => [ \&cmd_rebase, "Fetch and rebase your working directory",
                        { 'merge|m|M' => \$_merge,
                          'verbose|v' => \$_verbose,
                          'strategy|s=s' => \$_strategy,
                          'local|l' => \$_local,
                          'fetch-all|all' => \$_fetch_all,
                          'dry-run|n' => \$_dry_run,
                          'preserve-merges|p' => \$_preserve_merges,
                          %fc_opts } ],
        'commit-diff' => [ \&cmd_commit_diff,
                           'Commit a diff between two trees',
                        { 'message|m=s' => \$_message,
                          'file|F=s' => \$_file,
                          'revision|r=s' => \$_revision,
                        %cmt_opts } ],
        'info' => [ \&cmd_info,
                    "Show info about the latest SVN revision
                     on the current branch",
                    { 'url' => \$_url, } ],
        'blame' => [ \&Git::SVN::Log::cmd_blame,
                    "Show what revision and author last modified each line of a file",
                    { 'git-format' => \$_git_format } ],
        'reset' => [ \&cmd_reset,
                     "Undo fetches back to the specified SVN revision",
                     { 'revision|r=s' => \$_revision,
                       'parent|p' => \$_fetch_parent } ],
        'gc' => [ \&cmd_gc,
                  "Compress unhandled.log files in .git/svn and remove " .
                  "index files in .git/svn",
                {} ],
);

use Term::ReadLine;
package FakeTerm;
sub new {
        my ($class, $reason) = @_;
        return bless \$reason, shift;
}
sub readline {
        my $self = shift;
        die "Cannot use readline on FakeTerm: $$self";
}
package main;

my $term = eval {
        $ENV{"GIT_SVN_NOTTY"}
                ? new Term::ReadLine 'git-svn', \*STDIN, \*STDOUT
                : new Term::ReadLine 'git-svn';
};
if ($@) {
        $term = new FakeTerm "$@: going non-interactive";
}

my $cmd;
for (my $i = 0; $i < @ARGV; $i++) {
        if (defined $cmd{$ARGV[$i]}) {
                $cmd = $ARGV[$i];
                splice @ARGV, $i, 1;
                last;
        } elsif ($ARGV[$i] eq 'help') {
                $cmd = $ARGV[$i+1];
                usage(0);
        }
};

# make sure we're always running at the top-level working directory
unless ($cmd && $cmd =~ /(?:clone|init|multi-init)$/) {
        unless (-d $ENV{GIT_DIR}) {
                if ($git_dir_user_set) {
                        die "GIT_DIR=$ENV{GIT_DIR} explicitly set, ",
                            "but it is not a directory\n";
                }
                my $git_dir = delete $ENV{GIT_DIR};
                my $cdup = undef;
                git_cmd_try {
                        $cdup = command_oneline(qw/rev-parse --show-cdup/);
                        $git_dir = '.' unless ($cdup);
                        chomp $cdup if ($cdup);
                        $cdup = "." unless ($cdup && length $cdup);
                } "Already at toplevel, but $git_dir not found\n";
                chdir $cdup or die "Unable to chdir up to '$cdup'\n";
                unless (-d $git_dir) {
                        die "$git_dir still not found after going to ",
                            "'$cdup'\n";
                }
                $ENV{GIT_DIR} = $git_dir;
        }
        $_repository = Git->repository(Repository => $ENV{GIT_DIR});
}

my %opts = %{$cmd{$cmd}->[2]} if (defined $cmd);

read_git_config(\%opts);
if ($cmd && ($cmd eq 'log' || $cmd eq 'blame')) {
        Getopt::Long::Configure('pass_through');
}
my $rv = GetOptions(%opts, 'h|H' => \$_help, 'version|V' => \$_version,
                    'minimize-connections' => \$Git::SVN::Migration::_minimize,
                    'id|i=s' => \$Git::SVN::default_ref_id,
                    'svn-remote|remote|R=s' => sub {
                       $Git::SVN::no_reuse_existing = 1;
                       $Git::SVN::default_repo_id = $_[1] });
exit 1 if (!$rv && $cmd && $cmd ne 'log');

usage(0) if $_help;
version() if $_version;
usage(1) unless defined $cmd;
load_authors() if $_authors;
if (defined $_authors_prog) {
        $_authors_prog = "'" . File::Spec->rel2abs($_authors_prog) . "'";
}

unless ($cmd =~ /^(?:clone|init|multi-init|commit-diff)$/) {
        Git::SVN::Migration::migration_check();
}
Git::SVN::init_vars();
eval {
        Git::SVN::verify_remotes_sanity();
        $cmd{$cmd}->[0]->(@ARGV);
        post_fetch_checkout();
};
fatal $@ if $@;
exit 0;

####################### primary functions ######################
sub usage {
        my $exit = shift || 0;
        my $fd = $exit ? \*STDERR : \*STDOUT;
        print $fd <<"";
git-svn - bidirectional operations between a single Subversion tree and git
Usage: git svn <command> [options] [arguments]\n

        print $fd "Available commands:\n" unless $cmd;

        foreach (sort keys %cmd) {
                next if $cmd && $cmd ne $_;
                next if /^multi-/; # don't show deprecated commands
                print $fd '  ',pack('A17',$_),$cmd{$_}->[1],"\n";
                foreach (sort keys %{$cmd{$_}->[2]}) {
                        # mixed-case options are for .git/config only
                        next if /[A-Z]/ && /^[a-z]+$/i;
                        # prints out arguments as they should be passed:
                        my $x = s#[:=]s$## ? '<arg>' : s#[:=]i$## ? '<num>' : '';
                        print $fd ' ' x 21, join(', ', map { length $_ > 1 ?
                                                        "--$_" : "-$_" }
                                                split /\|/,$_)," $x\n";
                }
        }
        print $fd <<"";
\nGIT_SVN_ID may be set in the environment or via the --id/-i switch to an
arbitrary identifier if you're tracking multiple SVN branches/repositories in
one git repository and want to keep them separate.  See git-svn(1) for more
information.

        exit $exit;
}

sub version {
        ::_req_svn();
        print "git-svn version $VERSION (svn $SVN::Core::VERSION)\n";
        exit 0;
}

sub ask {
        my ($prompt, %arg) = @_;
        my $valid_re = $arg{valid_re};
        my $default = $arg{default};
        my $resp;
        my $i = 0;

        if ( !( defined($term->IN)
            && defined( fileno($term->IN) )
            && defined( $term->OUT )
            && defined( fileno($term->OUT) ) ) ){
                return defined($default) ? $default : undef;
        }

        while ($i++ < 10) {
                $resp = $term->readline($prompt);
                if (!defined $resp) { # EOF
                        print "\n";
                        return defined $default ? $default : undef;
                }
                if ($resp eq '' and defined $default) {
                        return $default;
                }
                if (!defined $valid_re or $resp =~ /$valid_re/) {
                        return $resp;
                }
        }
        return undef;
}

sub do_git_init_db {
        unless (-d $ENV{GIT_DIR}) {
                my @init_db = ('init');
                push @init_db, "--template=$_template" if defined $_template;
                if (defined $_shared) {
                        if ($_shared =~ /[a-z]/) {
                                push @init_db, "--shared=$_shared";
                        } else {
                                push @init_db, "--shared";
                        }
                }
                command_noisy(@init_db);
                $_repository = Git->repository(Repository => ".git");
        }
        my $set;
        my $pfx = "svn-remote.$Git::SVN::default_repo_id";
        foreach my $i (keys %icv) {
                die "'$set' and '$i' cannot both be set\n" if $set;
                next unless defined $icv{$i};
                command_noisy('config', "$pfx.$i", $icv{$i});
                $set = $i;
        }
        my $ignore_paths_regex = \$Git::SVN::Fetcher::_ignore_regex;
        command_noisy('config', "$pfx.ignore-paths", $$ignore_paths_regex)
                if defined $$ignore_paths_regex;
        my $ignore_refs_regex = \$Git::SVN::Ra::_ignore_refs_regex;
        command_noisy('config', "$pfx.ignore-refs", $$ignore_refs_regex)
                if defined $$ignore_refs_regex;

        if (defined $Git::SVN::Fetcher::_preserve_empty_dirs) {
                my $fname = \$Git::SVN::Fetcher::_placeholder_filename;
                command_noisy('config', "$pfx.preserve-empty-dirs", 'true');
                command_noisy('config', "$pfx.placeholder-filename", $$fname);
        }
}

sub init_subdir {
        my $repo_path = shift or return;
        mkpath([$repo_path]) unless -d $repo_path;
        chdir $repo_path or die "Couldn't chdir to $repo_path: $!\n";
        $ENV{GIT_DIR} = '.git';
        $_repository = Git->repository(Repository => $ENV{GIT_DIR});
}

sub cmd_clone {
        my ($url, $path) = @_;
        if (!defined $path &&
            (defined $_trunk || @_branches || @_tags ||
             defined $_stdlayout) &&
            $url !~ m#^[a-z\+]+://#) {
                $path = $url;
        }
        $path = basename($url) if !defined $path || !length $path;
        my $authors_absolute = $_authors ? File::Spec->rel2abs($_authors) : "";
        cmd_init($url, $path);
        command_oneline('config', 'svn.authorsfile', $authors_absolute)
            if $_authors;
        Git::SVN::fetch_all($Git::SVN::default_repo_id);
}

sub cmd_init {
        if (defined $_stdlayout) {
                $_trunk = 'trunk' if (!defined $_trunk);
                @_tags = 'tags' if (! @_tags);
                @_branches = 'branches' if (! @_branches);
        }
        if (defined $_trunk || @_branches || @_tags) {
                return cmd_multi_init(@_);
        }
        my $url = shift or die "SVN repository location required ",
                               "as a command-line argument\n";
        $url = canonicalize_url($url);
        init_subdir(@_);
        do_git_init_db();

        if ($Git::SVN::_minimize_url eq 'unset') {
                $Git::SVN::_minimize_url = 0;
        }

        Git::SVN->init($url);
}

sub cmd_fetch {
        if (grep /^\d+=./, @_) {
                die "'<rev>=<commit>' fetch arguments are ",
                    "no longer supported.\n";
        }
        my ($remote) = @_;
        if (@_ > 1) {
                die "Usage: $0 fetch [--all] [--parent] [svn-remote]\n";
        }
        $Git::SVN::no_reuse_existing = undef;
        if ($_fetch_parent) {
                my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
                unless ($gs) {
                        die "Unable to determine upstream SVN information from ",
                            "working tree history\n";
                }
                # just fetch, don't checkout.
                $_no_checkout = 'true';
                $_fetch_all ? $gs->fetch_all : $gs->fetch;
        } elsif ($_fetch_all) {
                cmd_multi_fetch();
        } else {
                $remote ||= $Git::SVN::default_repo_id;
                Git::SVN::fetch_all($remote, Git::SVN::read_all_remotes());
        }
}

sub cmd_set_tree {
        my (@commits) = @_;
        if ($_stdin || !@commits) {
                print "Reading from stdin...\n";
                @commits = ();
                while (<STDIN>) {
                        if (/\b($sha1_short)\b/o) {
                                unshift @commits, $1;
                        }
                }
        }
        my @revs;
        foreach my $c (@commits) {
                my @tmp = command('rev-parse',$c);
                if (scalar @tmp == 1) {
                        push @revs, $tmp[0];
                } elsif (scalar @tmp > 1) {
                        push @revs, reverse(command('rev-list',@tmp));
                } else {
                        fatal "Failed to rev-parse $c";
                }
        }
        my $gs = Git::SVN->new;
        my ($r_last, $cmt_last) = $gs->last_rev_commit;
        $gs->fetch;
        if (defined $gs->{last_rev} && $r_last != $gs->{last_rev}) {
                fatal "There are new revisions that were fetched ",
                      "and need to be merged (or acknowledged) ",
                      "before committing.\nlast rev: $r_last\n",
                      " current: $gs->{last_rev}";
        }
        $gs->set_tree($_) foreach @revs;
        print "Done committing ",scalar @revs," revisions to SVN\n";
        unlink $gs->{index};
}

sub split_merge_info_range {
        my ($range) = @_;
        if ($range =~ /(\d+)-(\d+)/) {
                return (int($1), int($2));
        } else {
                return (int($range), int($range));
        }
}

sub combine_ranges {
        my ($in) = @_;

        my @fnums = ();
        my @arr = split(/,/, $in);
        for my $element (@arr) {
                my ($start, $end) = split_merge_info_range($element);
                push @fnums, $start;
        }

        my @sorted = @arr [ sort {
                $fnums[$a] <=> $fnums[$b]
        } 0..$#arr ];

        my @return = ();
        my $last = -1;
        my $first = -1;
        for my $element (@sorted) {
                my ($start, $end) = split_merge_info_range($element);

                if ($last == -1) {
                        $first = $start;
                        $last = $end;
                        next;
                }
                if ($start <= $last+1) {
                        if ($end > $last) {
                                $last = $end;
                        }
                        next;
                }
                if ($first == $last) {
                        push @return, "$first";
                } else {
                        push @return, "$first-$last";
                }
                $first = $start;
                $last = $end;
        }

        if ($first != -1) {
                if ($first == $last) {
                        push @return, "$first";
                } else {
                        push @return, "$first-$last";
                }
        }

        return join(',', @return);
}

sub merge_revs_into_hash {
        my ($hash, $minfo) = @_;
        my @lines = split(' ', $minfo);

        for my $line (@lines) {
                my ($branchpath, $revs) = split(/:/, $line);

                if (exists($hash->{$branchpath})) {
                        # Merge the two revision sets
                        my $combined = "$hash->{$branchpath},$revs";
                        $hash->{$branchpath} = combine_ranges($combined);
                } else {
                        # Just do range combining for consolidation
                        $hash->{$branchpath} = combine_ranges($revs);
                }
        }
}

sub merge_merge_info {
        my ($mergeinfo_one, $mergeinfo_two) = @_;
        my %result_hash = ();

        merge_revs_into_hash(\%result_hash, $mergeinfo_one);
        merge_revs_into_hash(\%result_hash, $mergeinfo_two);

        my $result = '';
        # Sort below is for consistency's sake
        for my $branchname (sort keys(%result_hash)) {
                my $revlist = $result_hash{$branchname};
                $result .= "$branchname:$revlist\n"
        }
        return $result;
}

sub populate_merge_info {
        my ($d, $gs, $uuid, $linear_refs, $rewritten_parent) = @_;

        my %parentshash;
        read_commit_parents(\%parentshash, $d);
        my @parents = @{$parentshash{$d}};
        if ($#parents > 0) {
                # Merge commit
                my $all_parents_ok = 1;
                my $aggregate_mergeinfo = '';
                my $rooturl = $gs->repos_root;

                if (defined($rewritten_parent)) {
                        # Replace first parent with newly-rewritten version
                        shift @parents;
                        unshift @parents, $rewritten_parent;
                }

                foreach my $parent (@parents) {
                        my ($branchurl, $svnrev, $paruuid) =
                                cmt_metadata($parent);

                        unless (defined($svnrev)) {
                                # Should have been caught be preflight check
                                fatal "merge commit $d has ancestor $parent, but that change "
                     ."does not have git-svn metadata!";
                        }
                        unless ($branchurl =~ /^\Q$rooturl\E(.*)/) {
                                fatal "commit $parent git-svn metadata changed mid-run!";
                        }
                        my $branchpath = $1;

                        my $ra = Git::SVN::Ra->new($branchurl);
                        my (undef, undef, $props) =
                                $ra->get_dir(canonicalize_path("."), $svnrev);
                        my $par_mergeinfo = $props->{'svn:mergeinfo'};
                        unless (defined $par_mergeinfo) {
                                $par_mergeinfo = '';
                        }
                        # Merge previous mergeinfo values
                        $aggregate_mergeinfo =
                                merge_merge_info($aggregate_mergeinfo,
                                                                 $par_mergeinfo, 0);

                        next if $parent eq $parents[0]; # Skip first parent
                        # Add new changes being placed in tree by merge
                        my @cmd = (qw/rev-list --reverse/,
                                           $parent, qw/--not/);
                        foreach my $par (@parents) {
                                unless ($par eq $parent) {
                                        push @cmd, $par;
                                }
                        }
                        my @revsin = ();
                        my ($revlist, $ctx) = command_output_pipe(@cmd);
                        while (<$revlist>) {
                                my $irev = $_;
                                chomp $irev;
                                my (undef, $csvnrev, undef) =
                                        cmt_metadata($irev);
                                unless (defined $csvnrev) {
                                        # A child is missing SVN annotations...
                                        # this might be OK, or might not be.
                                        warn "W:child $irev is merged into revision "
                                                 ."$d but does not have git-svn metadata. "
                                                 ."This means git-svn cannot determine the "
                                                 ."svn revision numbers to place into the "
                                                 ."svn:mergeinfo property. You must ensure "
                                                 ."a branch is entirely committed to "
                                                 ."SVN before merging it in order for "
                                                 ."svn:mergeinfo population to function "
                                                 ."properly";
                                }
                                push @revsin, $csvnrev;
                        }
                        command_close_pipe($revlist, $ctx);

                        last unless $all_parents_ok;

                        # We now have a list of all SVN revnos which are
                        # merged by this particular parent. Integrate them.
                        next if $#revsin == -1;
                        my $newmergeinfo = "$branchpath:" . join(',', @revsin);
                        $aggregate_mergeinfo =
                                merge_merge_info($aggregate_mergeinfo,
                                                                 $newmergeinfo, 1);
                }
                if ($all_parents_ok and $aggregate_mergeinfo) {
                        return $aggregate_mergeinfo;
                }
        }

        return undef;
}

sub cmd_dcommit {
        my $head = shift;
        command_noisy(qw/update-index --refresh/);
        git_cmd_try { command_oneline(qw/diff-index --quiet HEAD/) }
                'Cannot dcommit with a dirty index.  Commit your changes first, '
                . "or stash them with `git stash'.\n";
        $head ||= 'HEAD';

        my $old_head;
        if ($head ne 'HEAD') {
                $old_head = eval {
                        command_oneline([qw/symbolic-ref -q HEAD/])
                };
                if ($old_head) {
                        $old_head =~ s{^refs/heads/}{};
                } else {
                        $old_head = eval { command_oneline(qw/rev-parse HEAD/) };
                }
                command(['checkout', $head], STDERR => 0);
        }

        my @refs;
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD', \@refs);
        unless ($gs) {
                die "Unable to determine upstream SVN information from ",
                    "$head history.\nPerhaps the repository is empty.";
        }

        if (defined $_commit_url) {
                $url = $_commit_url;
        } else {
                $url = eval { command_oneline('config', '--get',
                              "svn-remote.$gs->{repo_id}.commiturl") };
                if (!$url) {
                        $url = $gs->full_pushurl
                }
        }

        my $last_rev = $_revision if defined $_revision;
        if ($url) {
                print "Committing to $url ...\n";
        }
        my ($linear_refs, $parents) = linearize_history($gs, \@refs);
        if ($_no_rebase && scalar(@$linear_refs) > 1) {
                warn "Attempting to commit more than one change while ",
                     "--no-rebase is enabled.\n",
                     "If these changes depend on each other, re-running ",
                     "without --no-rebase may be required."
        }

        if (defined $_interactive){
                my $ask_default = "y";
                foreach my $d (@$linear_refs){
                        my ($fh, $ctx) = command_output_pipe(qw(show --summary), "$d");
                        while (<$fh>){
                                print $_;
                        }
                        command_close_pipe($fh, $ctx);
                        $_ = ask("Commit this patch to SVN? ([y]es (default)|[n]o|[q]uit|[a]ll): ",
                                 valid_re => qr/^(?:yes|y|no|n|quit|q|all|a)/i,
                                 default => $ask_default);
                        die "Commit this patch reply required" unless defined $_;
                        if (/^[nq]/i) {
                                exit(0);
                        } elsif (/^a/i) {
                                last;
                        }
                }
        }

        my $expect_url = $url;

        my $push_merge_info = eval {
                command_oneline(qw/config --get svn.pushmergeinfo/)
                };
        if (not defined($push_merge_info)
                        or $push_merge_info eq "false"
                        or $push_merge_info eq "no"
                        or $push_merge_info eq "never") {
                $push_merge_info = 0;
        }

        unless (defined($_merge_info) || ! $push_merge_info) {
                # Preflight check of changes to ensure no issues with mergeinfo
                # This includes check for uncommitted-to-SVN parents
                # (other than the first parent, which we will handle),
                # information from different SVN repos, and paths
                # which are not underneath this repository root.
                my $rooturl = $gs->repos_root;
                foreach my $d (@$linear_refs) {
                        my %parentshash;
                        read_commit_parents(\%parentshash, $d);
                        my @realparents = @{$parentshash{$d}};
                        if ($#realparents > 0) {
                                # Merge commit
                                shift @realparents; # Remove/ignore first parent
                                foreach my $parent (@realparents) {
                                        my ($branchurl, $svnrev, $paruuid) = cmt_metadata($parent);
                                        unless (defined $paruuid) {
                                                # A parent is missing SVN annotations...
                                                # abort the whole operation.
                                                fatal "$parent is merged into revision $d, "
                                                         ."but does not have git-svn metadata. "
                                                         ."Either dcommit the branch or use a "
                                                         ."local cherry-pick, FF merge, or rebase "
                                                         ."instead of an explicit merge commit.";
                                        }

                                        unless ($paruuid eq $uuid) {
                                                # Parent has SVN metadata from different repository
                                                fatal "merge parent $parent for change $d has "
                                                         ."git-svn uuid $paruuid, while current change "
                                                         ."has uuid $uuid!";
                                        }

                                        unless ($branchurl =~ /^\Q$rooturl\E(.*)/) {
                                                # This branch is very strange indeed.
                                                fatal "merge parent $parent for $d is on branch "
                                                         ."$branchurl, which is not under the "
                                                         ."git-svn root $rooturl!";
                                        }
                                }
                        }
                }
        }

        my $rewritten_parent;
        Git::SVN::remove_username($expect_url);
        if (defined($_merge_info)) {
                $_merge_info =~ tr{ }{\n};
        }
        while (1) {
                my $d = shift @$linear_refs or last;
                unless (defined $last_rev) {
                        (undef, $last_rev, undef) = cmt_metadata("$d~1");
                        unless (defined $last_rev) {
                                fatal "Unable to extract revision information ",
                                      "from commit $d~1";
                        }
                }
                if ($_dry_run) {
                        print "diff-tree $d~1 $d\n";
                } else {
                        my $cmt_rev;

                        unless (defined($_merge_info) || ! $push_merge_info) {
                                $_merge_info = populate_merge_info($d, $gs,
                                                             $uuid,
                                                             $linear_refs,
                                                             $rewritten_parent);
                        }

                        my %ed_opts = ( r => $last_rev,
                                        log => get_commit_entry($d)->{log},
                                        ra => Git::SVN::Ra->new($url),
                                        config => SVN::Core::config_get_config(
                                                $Git::SVN::Ra::config_dir
                                        ),
                                        tree_a => "$d~1",
                                        tree_b => $d,
                                        editor_cb => sub {
                                               print "Committed r$_[0]\n";
                                               $cmt_rev = $_[0];
                                        },
                                        mergeinfo => $_merge_info,
                                        svn_path => '');
                        if (!Git::SVN::Editor->new(\%ed_opts)->apply_diff) {
                                print "No changes\n$d~1 == $d\n";
                        } elsif ($parents->{$d} && @{$parents->{$d}}) {
                                $gs->{inject_parents_dcommit}->{$cmt_rev} =
                                                               $parents->{$d};
                        }
                        $_fetch_all ? $gs->fetch_all : $gs->fetch;
                        $last_rev = $cmt_rev;
                        next if $_no_rebase;

                        # we always want to rebase against the current HEAD,
                        # not any head that was passed to us
                        my @diff = command('diff-tree', $d,
                                           $gs->refname, '--');
                        my @finish;
                        if (@diff) {
                                @finish = rebase_cmd();
                                print STDERR "W: $d and ", $gs->refname,
                                             " differ, using @finish:\n",
                                             join("\n", @diff), "\n";
                        } else {
                                print "No changes between current HEAD and ",
                                      $gs->refname,
                                      "\nResetting to the latest ",
                                      $gs->refname, "\n";
                                @finish = qw/reset --mixed/;
                        }
                        command_noisy(@finish, $gs->refname);

                        $rewritten_parent = command_oneline(qw/rev-parse HEAD/);

                        if (@diff) {
                                @refs = ();
                                my ($url_, $rev_, $uuid_, $gs_) =
                                              working_head_info('HEAD', \@refs);
                                my ($linear_refs_, $parents_) =
                                              linearize_history($gs_, \@refs);
                                if (scalar(@$linear_refs) !=
                                    scalar(@$linear_refs_)) {
                                        fatal "# of revisions changed ",
                                          "\nbefore:\n",
                                          join("\n", @$linear_refs),
                                          "\n\nafter:\n",
                                          join("\n", @$linear_refs_), "\n",
                                          'If you are attempting to commit ',
                                          "merges, try running:\n\t",
                                          'git rebase --interactive',
                                          '--preserve-merges ',
                                          $gs->refname,
                                          "\nBefore dcommitting";
                                }
                                if ($url_ ne $expect_url) {
                                        if ($url_ eq $gs->metadata_url) {
                                                print
                                                  "Accepting rewritten URL:",
                                                  " $url_\n";
                                        } else {
                                                fatal
                                                  "URL mismatch after rebase:",
                                                  " $url_ != $expect_url";
                                        }
                                }
                                if ($uuid_ ne $uuid) {
                                        fatal "uuid mismatch after rebase: ",
                                              "$uuid_ != $uuid";
                                }
                                # remap parents
                                my (%p, @l, $i);
                                for ($i = 0; $i < scalar @$linear_refs; $i++) {
                                        my $new = $linear_refs_->[$i] or next;
                                        $p{$new} =
                                                $parents->{$linear_refs->[$i]};
                                        push @l, $new;
                                }
                                $parents = \%p;
                                $linear_refs = \@l;
                        }
                }
        }

        if ($old_head) {
                my $new_head = command_oneline(qw/rev-parse HEAD/);
                my $new_is_symbolic = eval {
                        command_oneline(qw/symbolic-ref -q HEAD/);
                };
                if ($new_is_symbolic) {
                        print "dcommitted the branch ", $head, "\n";
                } else {
                        print "dcommitted on a detached HEAD because you gave ",
                              "a revision argument.\n",
                              "The rewritten commit is: ", $new_head, "\n";
                }
                command(['checkout', $old_head], STDERR => 0);
        }

        unlink $gs->{index};
}

sub cmd_branch {
        my ($branch_name, $head) = @_;

        unless (defined $branch_name && length $branch_name) {
                die(($_tag ? "tag" : "branch") . " name required\n");
        }
        $head ||= 'HEAD';

        my (undef, $rev, undef, $gs) = working_head_info($head);
        my $src = $gs->full_pushurl;

        my $remote = Git::SVN::read_all_remotes()->{$gs->{repo_id}};
        my $allglobs = $remote->{ $_tag ? 'tags' : 'branches' };
        my $glob;
        if ($#{$allglobs} == 0) {
                $glob = $allglobs->[0];
        } else {
                unless(defined $_branch_dest) {
                        die "Multiple ",
                            $_tag ? "tag" : "branch",
                            " paths defined for Subversion repository.\n",
                            "You must specify where you want to create the ",
                            $_tag ? "tag" : "branch",
                            " with the --destination argument.\n";
                }
                foreach my $g (@{$allglobs}) {
                        my $re = Git::SVN::Editor::glob2pat($g->{path}->{left});
                        if ($_branch_dest =~ /$re/) {
                                $glob = $g;
                                last;
                        }
                }
                unless (defined $glob) {
                        my $dest_re = qr/\b\Q$_branch_dest\E\b/;
                        foreach my $g (@{$allglobs}) {
                                $g->{path}->{left} =~ /$dest_re/ or next;
                                if (defined $glob) {
                                        die "Ambiguous destination: ",
                                            $_branch_dest, "\nmatches both '",
                                            $glob->{path}->{left}, "' and '",
                                            $g->{path}->{left}, "'\n";
                                }
                                $glob = $g;
                        }
                        unless (defined $glob) {
                                die "Unknown ",
                                    $_tag ? "tag" : "branch",
                                    " destination $_branch_dest\n";
                        }
                }
        }
        my ($lft, $rgt) = @{ $glob->{path} }{qw/left right/};
        my $url;
        if (defined $_commit_url) {
                $url = $_commit_url;
        } else {
                $url = eval { command_oneline('config', '--get',
                        "svn-remote.$gs->{repo_id}.commiturl") };
                if (!$url) {
                        $url = $remote->{pushurl} || $remote->{url};
                }
        }
        my $dst = join '/', $url, $lft, $branch_name, ($rgt || ());

        if ($dst =~ /^https:/ && $src =~ /^http:/) {
                $src=~s/^http:/https:/;
        }

        ::_req_svn();

        my $ctx = SVN::Client->new(
                auth    => Git::SVN::Ra::_auth_providers(),
                log_msg => sub {
                        ${ $_[0] } = defined $_message
                                ? $_message
                                : 'Create ' . ($_tag ? 'tag ' : 'branch ' )
                                . $branch_name;
                },
        );

        eval {
                $ctx->ls($dst, 'HEAD', 0);
        } and die "branch ${branch_name} already exists\n";

        print "Copying ${src} at r${rev} to ${dst}...\n";
        $ctx->copy($src, $rev, $dst)
                unless $_dry_run;

        $gs->fetch_all;
}

sub cmd_find_rev {
        my $revision_or_hash = shift or die "SVN or git revision required ",
                                            "as a command-line argument\n";
        my $result;
        if ($revision_or_hash =~ /^r\d+$/) {
                my $head = shift;
                $head ||= 'HEAD';
                my @refs;
                my (undef, undef, $uuid, $gs) = working_head_info($head, \@refs);
                unless ($gs) {
                        die "Unable to determine upstream SVN information from ",
                            "$head history\n";
                }
                my $desired_revision = substr($revision_or_hash, 1);
                $result = $gs->rev_map_get($desired_revision, $uuid);
        } else {
                my (undef, $rev, undef) = cmt_metadata($revision_or_hash);
                $result = $rev;
        }
        print "$result\n" if $result;
}

sub auto_create_empty_directories {
        my ($gs) = @_;
        my $var = eval { command_oneline('config', '--get', '--bool',
                                         "svn-remote.$gs->{repo_id}.automkdirs") };
        # By default, create empty directories by consulting the unhandled log,
        # but allow setting it to 'false' to skip it.
        return !($var && $var eq 'false');
}

sub cmd_rebase {
        command_noisy(qw/update-index --refresh/);
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        unless ($gs) {
                die "Unable to determine upstream SVN information from ",
                    "working tree history\n";
        }
        if ($_dry_run) {
                print "Remote Branch: " . $gs->refname . "\n";
                print "SVN URL: " . $url . "\n";
                return;
        }
        if (command(qw/diff-index HEAD --/)) {
                print STDERR "Cannot rebase with uncommited changes:\n";
                command_noisy('status');
                exit 1;
        }
        unless ($_local) {
                # rebase will checkout for us, so no need to do it explicitly
                $_no_checkout = 'true';
                $_fetch_all ? $gs->fetch_all : $gs->fetch;
        }
        command_noisy(rebase_cmd(), $gs->refname);
        if (auto_create_empty_directories($gs)) {
                $gs->mkemptydirs;
        }
}

sub cmd_show_ignore {
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        $gs ||= Git::SVN->new;
        my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
        $gs->prop_walk($gs->{path}, $r, sub {
                my ($gs, $path, $props) = @_;
                print STDOUT "\n# $path\n";
                my $s = $props->{'svn:ignore'} or return;
                $s =~ s/[\r\n]+/\n/g;
                $s =~ s/^\n+//;
                chomp $s;
                $s =~ s#^#$path#gm;
                print STDOUT "$s\n";
        });
}

sub cmd_show_externals {
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        $gs ||= Git::SVN->new;
        my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
        $gs->prop_walk($gs->{path}, $r, sub {
                my ($gs, $path, $props) = @_;
                print STDOUT "\n# $path\n";
                my $s = $props->{'svn:externals'} or return;
                $s =~ s/[\r\n]+/\n/g;
                chomp $s;
                $s =~ s#^#$path#gm;
                print STDOUT "$s\n";
        });
}

sub cmd_create_ignore {
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        $gs ||= Git::SVN->new;
        my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
        $gs->prop_walk($gs->{path}, $r, sub {
                my ($gs, $path, $props) = @_;
                # $path is of the form /path/to/dir/
                $path = '.' . $path;
                # SVN can have attributes on empty directories,
                # which git won't track
                mkpath([$path]) unless -d $path;
                my $ignore = $path . '.gitignore';
                my $s = $props->{'svn:ignore'} or return;
                open(GITIGNORE, '>', $ignore)
                  or fatal("Failed to open `$ignore' for writing: $!");
                $s =~ s/[\r\n]+/\n/g;
                $s =~ s/^\n+//;
                chomp $s;
                # Prefix all patterns so that the ignore doesn't apply
                # to sub-directories.
                $s =~ s#^#/#gm;
                print GITIGNORE "$s\n";
                close(GITIGNORE)
                  or fatal("Failed to close `$ignore': $!");
                command_noisy('add', '-f', $ignore);
        });
}

sub cmd_mkdirs {
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        $gs ||= Git::SVN->new;
        $gs->mkemptydirs($_revision);
}

sub canonicalize_path {
        my ($path) = @_;
        my $dot_slash_added = 0;
        if (substr($path, 0, 1) ne "/") {
                $path = "./" . $path;
                $dot_slash_added = 1;
        }
        # File::Spec->canonpath doesn't collapse x/../y into y (for a
        # good reason), so let's do this manually.
        $path =~ s#/+#/#g;
        $path =~ s#/\.(?:/|$)#/#g;
        $path =~ s#/[^/]+/\.\.##g;
        $path =~ s#/$##g;
        $path =~ s#^\./## if $dot_slash_added;
        $path =~ s#^/##;
        $path =~ s#^\.$##;
        return $path;
}

sub canonicalize_url {
        my ($url) = @_;
        $url =~ s#^([^:]+://[^/]*/)(.*)$#$1 . canonicalize_path($2)#e;
        return $url;
}

# get_svnprops(PATH)
# ------------------
# Helper for cmd_propget and cmd_proplist below.
sub get_svnprops {
        my $path = shift;
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        $gs ||= Git::SVN->new;

        # prefix THE PATH by the sub-directory from which the user
        # invoked us.
        $path = $cmd_dir_prefix . $path;
        fatal("No such file or directory: $path") unless -e $path;
        my $is_dir = -d $path ? 1 : 0;
        $path = $gs->{path} . '/' . $path;

        # canonicalize the path (otherwise libsvn will abort or fail to
        # find the file)
        $path = canonicalize_path($path);

        my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
        my $props;
        if ($is_dir) {
                (undef, undef, $props) = $gs->ra->get_dir($path, $r);
        }
        else {
                (undef, $props) = $gs->ra->get_file($path, $r, undef);
        }
        return $props;
}

# cmd_propget (PROP, PATH)
# ------------------------
# Print the SVN property PROP for PATH.
sub cmd_propget {
        my ($prop, $path) = @_;
        $path = '.' if not defined $path;
        usage(1) if not defined $prop;
        my $props = get_svnprops($path);
        if (not defined $props->{$prop}) {
                fatal("`$path' does not have a `$prop' SVN property.");
        }
        print $props->{$prop} . "\n";
}

# cmd_proplist (PATH)
# -------------------
# Print the list of SVN properties for PATH.
sub cmd_proplist {
        my $path = shift;
        $path = '.' if not defined $path;
        my $props = get_svnprops($path);
        print "Properties on '$path':\n";
        foreach (sort keys %{$props}) {
                print "  $_\n";
        }
}

sub cmd_multi_init {
        my $url = shift;
        unless (defined $_trunk || @_branches || @_tags) {
                usage(1);
        }

        $_prefix = '' unless defined $_prefix;
        if (defined $url) {
                $url = canonicalize_url($url);
                init_subdir(@_);
        }
        do_git_init_db();
        if (defined $_trunk) {
                $_trunk =~ s#^/+##;
                my $trunk_ref = 'refs/remotes/' . $_prefix . 'trunk';
                # try both old-style and new-style lookups:
                my $gs_trunk = eval { Git::SVN->new($trunk_ref) };
                unless ($gs_trunk) {
                        my ($trunk_url, $trunk_path) =
                                              complete_svn_url($url, $_trunk);
                        $gs_trunk = Git::SVN->init($trunk_url, $trunk_path,
                                                   undef, $trunk_ref);
                }
        }
        return unless @_branches || @_tags;
        my $ra = $url ? Git::SVN::Ra->new($url) : undef;
        foreach my $path (@_branches) {
                complete_url_ls_init($ra, $path, '--branches/-b', $_prefix);
        }
        foreach my $path (@_tags) {
                complete_url_ls_init($ra, $path, '--tags/-t', $_prefix.'tags/');
        }
}

sub cmd_multi_fetch {
        $Git::SVN::no_reuse_existing = undef;
        my $remotes = Git::SVN::read_all_remotes();
        foreach my $repo_id (sort keys %$remotes) {
                if ($remotes->{$repo_id}->{url}) {
                        Git::SVN::fetch_all($repo_id, $remotes);
                }
        }
}

# this command is special because it requires no metadata
sub cmd_commit_diff {
        my ($ta, $tb, $url) = @_;
        my $usage = "Usage: $0 commit-diff -r<revision> ".
                    "<tree-ish> <tree-ish> [<URL>]";
        fatal($usage) if (!defined $ta || !defined $tb);
        my $svn_path = '';
        if (!defined $url) {
                my $gs = eval { Git::SVN->new };
                if (!$gs) {
                        fatal("Needed URL or usable git-svn --id in ",
                              "the command-line\n", $usage);
                }
                $url = $gs->{url};
                $svn_path = $gs->{path};
        }
        unless (defined $_revision) {
                fatal("-r|--revision is a required argument\n", $usage);
        }
        if (defined $_message && defined $_file) {
                fatal("Both --message/-m and --file/-F specified ",
                      "for the commit message.\n",
                      "I have no idea what you mean");
        }
        if (defined $_file) {
                $_message = file_to_s($_file);
        } else {
                $_message ||= get_commit_entry($tb)->{log};
        }
        my $ra ||= Git::SVN::Ra->new($url);
        my $r = $_revision;
        if ($r eq 'HEAD') {
                $r = $ra->get_latest_revnum;
        } elsif ($r !~ /^\d+$/) {
                die "revision argument: $r not understood by git-svn\n";
        }
        my %ed_opts = ( r => $r,
                        log => $_message,
                        ra => $ra,
                        tree_a => $ta,
                        tree_b => $tb,
                        editor_cb => sub { print "Committed r$_[0]\n" },
                        svn_path => $svn_path );
        if (!Git::SVN::Editor->new(\%ed_opts)->apply_diff) {
                print "No changes\n$ta == $tb\n";
        }
}

sub escape_uri_only {
        my ($uri) = @_;
        my @tmp;
        foreach (split m{/}, $uri) {
                s/([^~\w.%+-]|%(?![a-fA-F0-9]{2}))/sprintf("%%%02X",ord($1))/eg;
                push @tmp, $_;
        }
        join('/', @tmp);
}

sub escape_url {
        my ($url) = @_;
        if ($url =~ m#^([^:]+)://([^/]*)(.*)$#) {
                my ($scheme, $domain, $uri) = ($1, $2, escape_uri_only($3));
                $url = "$scheme://$domain$uri";
        }
        $url;
}

sub cmd_info {
        my $path = canonicalize_path(defined($_[0]) ? $_[0] : ".");
        my $fullpath = canonicalize_path($cmd_dir_prefix . $path);
        if (exists $_[1]) {
                die "Too many arguments specified\n";
        }

        my ($file_type, $diff_status) = find_file_type_and_diff_status($path);

        if (!$file_type && !$diff_status) {
                print STDERR "svn: '$path' is not under version control\n";
                exit 1;
        }

        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        unless ($gs) {
                die "Unable to determine upstream SVN information from ",
                    "working tree history\n";
        }

        # canonicalize_path() will return "" to make libsvn 1.5.x happy,
        $path = "." if $path eq "";

        my $full_url = $url . ($fullpath eq "" ? "" : "/$fullpath");

        if ($_url) {
                print escape_url($full_url), "\n";
                return;
        }

        my $result = "Path: $path\n";
        $result .= "Name: " . basename($path) . "\n" if $file_type ne "dir";
        $result .= "URL: " . escape_url($full_url) . "\n";

        eval {
                my $repos_root = $gs->repos_root;
                Git::SVN::remove_username($repos_root);
                $result .= "Repository Root: " . escape_url($repos_root) . "\n";
        };
        if ($@) {
                $result .= "Repository Root: (offline)\n";
        }
        ::_req_svn();
        $result .= "Repository UUID: $uuid\n" unless $diff_status eq "A" &&
                (::compare_svn_version('1.5.4') <= 0 || $file_type ne "dir");
        $result .= "Revision: " . ($diff_status eq "A" ? 0 : $rev) . "\n";

        $result .= "Node Kind: " .
                   ($file_type eq "dir" ? "directory" : "file") . "\n";

        my $schedule = $diff_status eq "A"
                       ? "add"
                       : ($diff_status eq "D" ? "delete" : "normal");
        $result .= "Schedule: $schedule\n";

        if ($diff_status eq "A") {
                print $result, "\n";
                return;
        }

        my ($lc_author, $lc_rev, $lc_date_utc);
        my @args = Git::SVN::Log::git_svn_log_cmd($rev, $rev, "--", $fullpath);
        my $log = command_output_pipe(@args);
        my $esc_color = qr/(?:\033\[(?:(?:\d+;)*\d*)?m)*/;
        while (<$log>) {
                if (/^${esc_color}author (.+) <[^>]+> (\d+) ([\-\+]?\d+)$/o) {
                        $lc_author = $1;
                        $lc_date_utc = Git::SVN::Log::parse_git_date($2, $3);
                } elsif (/^${esc_color}    (git-svn-id:.+)$/o) {
                        (undef, $lc_rev, undef) = ::extract_metadata($1);
                }
        }
        close $log;

        Git::SVN::Log::set_local_timezone();

        $result .= "Last Changed Author: $lc_author\n";
        $result .= "Last Changed Rev: $lc_rev\n";
        $result .= "Last Changed Date: " .
                   Git::SVN::Log::format_svn_date($lc_date_utc) . "\n";

        if ($file_type ne "dir") {
                my $text_last_updated_date =
                    ($diff_status eq "D" ? $lc_date_utc : (stat $path)[9]);
                $result .=
                    "Text Last Updated: " .
                    Git::SVN::Log::format_svn_date($text_last_updated_date) .
                    "\n";
                my $checksum;
                if ($diff_status eq "D") {
                        my ($fh, $ctx) =
                            command_output_pipe(qw(cat-file blob), "HEAD:$path");
                        if ($file_type eq "link") {
                                my $file_name = <$fh>;
                                $checksum = md5sum("link $file_name");
                        } else {
                                $checksum = md5sum($fh);
                        }
                        command_close_pipe($fh, $ctx);
                } elsif ($file_type eq "link") {
                        my $file_name =
                            command(qw(cat-file blob), "HEAD:$path");
                        $checksum =
                            md5sum("link " . $file_name);
                } else {
                        open FILE, "<", $path or die $!;
                        $checksum = md5sum(\*FILE);
                        close FILE or die $!;
                }
                $result .= "Checksum: " . $checksum . "\n";
        }

        print $result, "\n";
}

sub cmd_reset {
        my $target = shift || $_revision or die "SVN revision required\n";
        $target = $1 if $target =~ /^r(\d+)$/;
        $target =~ /^\d+$/ or die "Numeric SVN revision expected\n";
        my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
        unless ($gs) {
                die "Unable to determine upstream SVN information from ".
                    "history\n";
        }
        my ($r, $c) = $gs->find_rev_before($target, not $_fetch_parent);
        die "Cannot find SVN revision $target\n" unless defined($c);
        $gs->rev_map_set($r, $c, 'reset', $uuid);
        print "r$r = $c ($gs->{ref_id})\n";
}

sub cmd_gc {
        if (!can_compress()) {
                warn "Compress::Zlib could not be found; unhandled.log " .
                     "files will not be compressed.\n";
        }
        find({ wanted => \&gc_directory, no_chdir => 1}, "$ENV{GIT_DIR}/svn");
}

########################### utility functions #########################

sub rebase_cmd {
        my @cmd = qw/rebase/;
        push @cmd, '-v' if $_verbose;
        push @cmd, qw/--merge/ if $_merge;
        push @cmd, "--strategy=$_strategy" if $_strategy;
        push @cmd, "--preserve-merges" if $_preserve_merges;
        @cmd;
}

sub post_fetch_checkout {
        return if $_no_checkout;
        return if verify_ref('HEAD^0');
        my $gs = $Git::SVN::_head or return;

        # look for "trunk" ref if it exists
        my $remote = Git::SVN::read_all_remotes()->{$gs->{repo_id}};
        my $fetch = $remote->{fetch};
        if ($fetch) {
                foreach my $p (keys %$fetch) {
                        basename($fetch->{$p}) eq 'trunk' or next;
                        $gs = Git::SVN->new($fetch->{$p}, $gs->{repo_id}, $p);
                        last;
                }
        }

        command_noisy(qw(update-ref HEAD), $gs->refname);
        return unless verify_ref('HEAD^0');

        return if $ENV{GIT_DIR} !~ m#^(?:.*/)?\.git$#;
        my $index = $ENV{GIT_INDEX_FILE} || "$ENV{GIT_DIR}/index";
        return if -f $index;

        return if command_oneline(qw/rev-parse --is-inside-work-tree/) eq 'false';
        return if command_oneline(qw/rev-parse --is-inside-git-dir/) eq 'true';
        command_noisy(qw/read-tree -m -u -v HEAD HEAD/);
        print STDERR "Checked out HEAD:\n  ",
                     $gs->full_url, " r", $gs->last_rev, "\n";
        if (auto_create_empty_directories($gs)) {
                $gs->mkemptydirs($gs->last_rev);
        }
}

sub complete_svn_url {
        my ($url, $path) = @_;
        $path =~ s#/+$##;
        if ($path !~ m#^[a-z\+]+://#) {
                if (!defined $url || $url !~ m#^[a-z\+]+://#) {
                        fatal("E: '$path' is not a complete URL ",
                              "and a separate URL is not specified");
                }
                return ($url, $path);
        }
        return ($path, '');
}

sub complete_url_ls_init {
        my ($ra, $repo_path, $switch, $pfx) = @_;
        unless ($repo_path) {
                print STDERR "W: $switch not specified\n";
                return;
        }
        $repo_path =~ s#/+$##;
        if ($repo_path =~ m#^[a-z\+]+://#) {
                $ra = Git::SVN::Ra->new($repo_path);
                $repo_path = '';
        } else {
                $repo_path =~ s#^/+##;
                unless ($ra) {
                        fatal("E: '$repo_path' is not a complete URL ",
                              "and a separate URL is not specified");
                }
        }
        my $url = $ra->{url};
        my $gs = Git::SVN->init($url, undef, undef, undef, 1);
        my $k = "svn-remote.$gs->{repo_id}.url";
        my $orig_url = eval { command_oneline(qw/config --get/, $k) };
        if ($orig_url && ($orig_url ne $gs->{url})) {
                die "$k already set: $orig_url\n",
                    "wanted to set to: $gs->{url}\n";
        }
        command_oneline('config', $k, $gs->{url}) unless $orig_url;
        my $remote_path = "$gs->{path}/$repo_path";
        $remote_path =~ s{%([0-9A-F]{2})}{chr hex($1)}ieg;
        $remote_path =~ s#/+#/#g;
        $remote_path =~ s#^/##g;
        $remote_path .= "/*" if $remote_path !~ /\*/;
        my ($n) = ($switch =~ /^--(\w+)/);
        if (length $pfx && $pfx !~ m#/$#) {
                die "--prefix='$pfx' must have a trailing slash '/'\n";
        }
        command_noisy('config',
                      '--add',
                      "svn-remote.$gs->{repo_id}.$n",
                      "$remote_path:refs/remotes/$pfx*" .
                        ('/*' x (($remote_path =~ tr/*/*/) - 1)) );
}

sub verify_ref {
        my ($ref) = @_;
        eval { command_oneline([ 'rev-parse', '--verify', $ref ],
                               { STDERR => 0 }); };
}

sub get_tree_from_treeish {
        my ($treeish) = @_;
        # $treeish can be a symbolic ref, too:
        my $type = command_oneline(qw/cat-file -t/, $treeish);
        my $expected;
        while ($type eq 'tag') {
                ($treeish, $type) = command(qw/cat-file tag/, $treeish);
        }
        if ($type eq 'commit') {
                $expected = (grep /^tree /, command(qw/cat-file commit/,
                                                    $treeish))[0];
                ($expected) = ($expected =~ /^tree ($sha1)$/o);
                die "Unable to get tree from $treeish\n" unless $expected;
        } elsif ($type eq 'tree') {
                $expected = $treeish;
        } else {
                die "$treeish is a $type, expected tree, tag or commit\n";
        }
        return $expected;
}

sub get_commit_entry {
        my ($treeish) = shift;
        my %log_entry = ( log => '', tree => get_tree_from_treeish($treeish) );
        my $commit_editmsg = "$ENV{GIT_DIR}/COMMIT_EDITMSG";
        my $commit_msg = "$ENV{GIT_DIR}/COMMIT_MSG";
        open my $log_fh, '>', $commit_editmsg or croak $!;

        my $type = command_oneline(qw/cat-file -t/, $treeish);
        if ($type eq 'commit' || $type eq 'tag') {
                my ($msg_fh, $ctx) = command_output_pipe('cat-file',
                                                         $type, $treeish);
                my $in_msg = 0;
                my $author;
                my $saw_from = 0;
                my $msgbuf = "";
                while (<$msg_fh>) {
                        if (!$in_msg) {
                                $in_msg = 1 if (/^\s*$/);
                                $author = $1 if (/^author (.*>)/);
                        } elsif (/^git-svn-id: /) {
                                # skip this for now, we regenerate the
                                # correct one on re-fetch anyways
                                # TODO: set *:merge properties or like...
                        } else {
                                if (/^From:/ || /^Signed-off-by:/) {
                                        $saw_from = 1;
                                }
                                $msgbuf .= $_;
                        }
                }
                $msgbuf =~ s/\s+$//s;
                if ($Git::SVN::_add_author_from && defined($author)
                    && !$saw_from) {
                        $msgbuf .= "\n\nFrom: $author";
                }
                print $log_fh $msgbuf or croak $!;
                command_close_pipe($msg_fh, $ctx);
        }
        close $log_fh or croak $!;

        if ($_edit || ($type eq 'tree')) {
                chomp(my $editor = command_oneline(qw(var GIT_EDITOR)));
                system('sh', '-c', $editor.' "$@"', $editor, $commit_editmsg);
        }
        rename $commit_editmsg, $commit_msg or croak $!;
        {
                require Encode;
                # SVN requires messages to be UTF-8 when entering the repo
                local $/;
                open $log_fh, '<', $commit_msg or croak $!;
                binmode $log_fh;
                chomp($log_entry{log} = <$log_fh>);

                my $enc = Git::config('i18n.commitencoding') || 'UTF-8';
                my $msg = $log_entry{log};

                eval { $msg = Encode::decode($enc, $msg, 1) };
                if ($@) {
                        die "Could not decode as $enc:\n", $msg,
                            "\nPerhaps you need to set i18n.commitencoding\n";
                }

                eval { $msg = Encode::encode('UTF-8', $msg, 1) };
                die "Could not encode as UTF-8:\n$msg\n" if $@;

                $log_entry{log} = $msg;

                close $log_fh or croak $!;
        }
        unlink $commit_msg;
        \%log_entry;
}

sub s_to_file {
        my ($str, $file, $mode) = @_;
        open my $fd,'>',$file or croak $!;
        print $fd $str,"\n" or croak $!;
        close $fd or croak $!;
        chmod ($mode &~ umask, $file) if (defined $mode);
}

sub file_to_s {
        my $file = shift;
        open my $fd,'<',$file or croak "$!: file: $file\n";
        local $/;
        my $ret = <$fd>;
        close $fd or croak $!;
        $ret =~ s/\s*$//s;
        return $ret;
}

# '<svn username> = real-name <email address>' mapping based on git-svnimport:
sub load_authors {
        open my $authors, '<', $_authors or die "Can't open $_authors $!\n";
        my $log = $cmd eq 'log';
        while (<$authors>) {
                chomp;
                next unless /^(.+?|\(no author\))\s*=\s*(.+?)\s*<(.+)>\s*$/;
                my ($user, $name, $email) = ($1, $2, $3);
                if ($log) {
                        $Git::SVN::Log::rusers{"$name <$email>"} = $user;
                } else {
                        $users{$user} = [$name, $email];
                }
        }
        close $authors or croak $!;
}

# convert GetOpt::Long specs for use by git-config
sub read_git_config {
        my $opts = shift;
        my @config_only;
        foreach my $o (keys %$opts) {
                # if we have mixedCase and a long option-only, then
                # it's a config-only variable that we don't need for
                # the command-line.
                push @config_only, $o if ($o =~ /[A-Z]/ && $o =~ /^[a-z]+$/i);
                my $v = $opts->{$o};
                my ($key) = ($o =~ /^([a-zA-Z\-]+)/);
                $key =~ s/-//g;
                my $arg = 'git config';
                $arg .= ' --int' if ($o =~ /[:=]i$/);
                $arg .= ' --bool' if ($o !~ /[:=][sfi]$/);
                if (ref $v eq 'ARRAY') {
                        chomp(my @tmp = `$arg --get-all svn.$key`);
                        @$v = @tmp if @tmp;
                } else {
                        chomp(my $tmp = `$arg --get svn.$key`);
                        if ($tmp && !($arg =~ / --bool/ && $tmp eq 'false')) {
                                $$v = $tmp;
                        }
                }
        }
        delete @$opts{@config_only} if @config_only;
}

sub extract_metadata {
        my $id = shift or return (undef, undef, undef);
        my ($url, $rev, $uuid) = ($id =~ /^\s*git-svn-id:\s+(.*)\@(\d+)
                                                        \s([a-f\d\-]+)$/ix);
        if (!defined $rev || !$uuid || !$url) {
                # some of the original repositories I made had
                # identifiers like this:
                ($rev, $uuid) = ($id =~/^\s*git-svn-id:\s(\d+)\@([a-f\d\-]+)/i);
        }
        return ($url, $rev, $uuid);
}

sub cmt_metadata {
        return extract_metadata((grep(/^git-svn-id: /,
                command(qw/cat-file commit/, shift)))[-1]);
}

sub cmt_sha2rev_batch {
        my %s2r;
        my ($pid, $in, $out, $ctx) = command_bidi_pipe(qw/cat-file --batch/);
        my $list = shift;

        foreach my $sha (@{$list}) {
                my $first = 1;
                my $size = 0;
                print $out $sha, "\n";

                while (my $line = <$in>) {
                        if ($first && $line =~ /^[[:xdigit:]]{40}\smissing$/) {
                                last;
                        } elsif ($first &&
                               $line =~ /^[[:xdigit:]]{40}\scommit\s(\d+)$/) {
                                $first = 0;
                                $size = $1;
                                next;
                        } elsif ($line =~ /^(git-svn-id: )/) {
                                my (undef, $rev, undef) =
                                                      extract_metadata($line);
                                $s2r{$sha} = $rev;
                        }

                        $size -= length($line);
                        last if ($size == 0);
                }
        }

        command_close_bidi_pipe($pid, $in, $out, $ctx);

        return \%s2r;
}

sub working_head_info {
        my ($head, $refs) = @_;
        my @args = qw/rev-list --first-parent --pretty=medium/;
        my ($fh, $ctx) = command_output_pipe(@args, $head);
        my $hash;
        my %max;
        while (<$fh>) {
                if ( m{^commit ($::sha1)$} ) {
                        unshift @$refs, $hash if $hash and $refs;
                        $hash = $1;
                        next;
                }
                next unless s{^\s*(git-svn-id:)}{$1};
                my ($url, $rev, $uuid) = extract_metadata($_);
                if (defined $url && defined $rev) {
                        next if $max{$url} and $max{$url} < $rev;
                        if (my $gs = Git::SVN->find_by_url($url)) {
                                my $c = $gs->rev_map_get($rev, $uuid);
                                if ($c && $c eq $hash) {
                                        close $fh; # break the pipe
                                        return ($url, $rev, $uuid, $gs);
                                } else {
                                        $max{$url} ||= $gs->rev_map_max;
                                }
                        }
                }
        }
        command_close_pipe($fh, $ctx);
        (undef, undef, undef, undef);
}

sub read_commit_parents {
        my ($parents, $c) = @_;
        chomp(my $p = command_oneline(qw/rev-list --parents -1/, $c));
        $p =~ s/^($c)\s*// or die "rev-list --parents -1 $c failed!\n";
        @{$parents->{$c}} = split(/ /, $p);
}

sub linearize_history {
        my ($gs, $refs) = @_;
        my %parents;
        foreach my $c (@$refs) {
                read_commit_parents(\%parents, $c);
        }

        my @linear_refs;
        my %skip = ();
        my $last_svn_commit = $gs->last_commit;
        foreach my $c (reverse @$refs) {
                next if $c eq $last_svn_commit;
                last if $skip{$c};

                unshift @linear_refs, $c;
                $skip{$c} = 1;

                # we only want the first parent to diff against for linear
                # history, we save the rest to inject when we finalize the
                # svn commit
                my $fp_a = verify_ref("$c~1");
                my $fp_b = shift @{$parents{$c}} if $parents{$c};
                if (!$fp_a || !$fp_b) {
                        die "Commit $c\n",
                            "has no parent commit, and therefore ",
                            "nothing to diff against.\n",
                            "You should be working from a repository ",
                            "originally created by git-svn\n";
                }
                if ($fp_a ne $fp_b) {
                        die "$c~1 = $fp_a, however parsing commit $c ",
                            "revealed that:\n$c~1 = $fp_b\nBUG!\n";
                }

                foreach my $p (@{$parents{$c}}) {
                        $skip{$p} = 1;
                }
        }
        (\@linear_refs, \%parents);
}

sub find_file_type_and_diff_status {
        my ($path) = @_;
        return ('dir', '') if $path eq '';

        my $diff_output =
            command_oneline(qw(diff --cached --name-status --), $path) || "";
        my $diff_status = (split(' ', $diff_output))[0] || "";

        my $ls_tree = command_oneline(qw(ls-tree HEAD), $path) || "";

        return (undef, undef) if !$diff_status && !$ls_tree;

        if ($diff_status eq "A") {
                return ("link", $diff_status) if -l $path;
                return ("dir", $diff_status) if -d $path;
                return ("file", $diff_status);
        }

        my $mode = (split(' ', $ls_tree))[0] || "";

        return ("link", $diff_status) if $mode eq "120000";
        return ("dir", $diff_status) if $mode eq "040000";
        return ("file", $diff_status);
}

sub md5sum {
        my $arg = shift;
        my $ref = ref $arg;
        my $md5 = Digest::MD5->new();
        if ($ref eq 'GLOB' || $ref eq 'IO::File' || $ref eq 'File::Temp') {
                $md5->addfile($arg) or croak $!;
        } elsif ($ref eq 'SCALAR') {
                $md5->add($$arg) or croak $!;
        } elsif (!$ref) {
                $md5->add($arg) or croak $!;
        } else {
                fatal "Can't provide MD5 hash for unknown ref type: '", $ref, "'";
        }
        return $md5->hexdigest();
}

sub gc_directory {
        if (can_compress() && -f $_ && basename($_) eq "unhandled.log") {
                my $out_filename = $_ . ".gz";
                open my $in_fh, "<", $_ or die "Unable to open $_: $!\n";
                binmode $in_fh;
                my $gz = Compress::Zlib::gzopen($out_filename, "ab") or
                                die "Unable to open $out_filename: $!\n";

                my $res;
                while ($res = sysread($in_fh, my $str, 1024)) {
                        $gz->gzwrite($str) or
                                die "Unable to write: ".$gz->gzerror()."!\n";
                }
                unlink $_ or die "unlink $File::Find::name: $!\n";
        } elsif (-f $_ && basename($_) eq "index") {
                unlink $_ or die "unlink $_: $!\n";
        }
}

package Git::SVN;
use strict;
use warnings;
use Fcntl qw/:DEFAULT :seek/;
use constant rev_map_fmt => 'NH40';
use vars qw/$default_repo_id $default_ref_id $_no_metadata $_follow_parent
            $_repack $_repack_flags $_use_svm_props $_head
            $_use_svnsync_props $no_reuse_existing $_minimize_url
            $_use_log_author $_add_author_from $_localtime/;
use Carp qw/croak/;
use File::Path qw/mkpath/;
use File::Copy qw/copy/;
use IPC::Open3;
use Time::Local;
use Memoize;  # core since 5.8.0, Jul 2002
use Memoize::Storable;
use POSIX qw(:signal_h);

use Git::SVN::Utils qw(fatal can_compress);

my $can_use_yaml;
BEGIN {
        $can_use_yaml = eval { require Git::SVN::Memoize::YAML; 1};
}

my ($_gc_nr, $_gc_period);

# properties that we do not log:
my %SKIP_PROP;
BEGIN {
        %SKIP_PROP = map { $_ => 1 } qw/svn:wc:ra_dav:version-url
                                        svn:special svn:executable
                                        svn:entry:committed-rev
                                        svn:entry:last-author
                                        svn:entry:uuid
                                        svn:entry:committed-date/;

        # some options are read globally, but can be overridden locally
        # per [svn-remote "..."] section.  Command-line options will *NOT*
        # override options set in an [svn-remote "..."] section
        no strict 'refs';
        for my $option (qw/follow_parent no_metadata use_svm_props
                           use_svnsync_props/) {
                my $key = $option;
                $key =~ tr/_//d;
                my $prop = "-$option";
                *$option = sub {
                        my ($self) = @_;
                        return $self->{$prop} if exists $self->{$prop};
                        my $k = "svn-remote.$self->{repo_id}.$key";
                        eval { command_oneline(qw/config --get/, $k) };
                        if ($@) {
                                $self->{$prop} = ${"Git::SVN::_$option"};
                        } else {
                                my $v = command_oneline(qw/config --bool/,$k);
                                $self->{$prop} = $v eq 'false' ? 0 : 1;
                        }
                        return $self->{$prop};
                }
        }
}


my (%LOCKFILES, %INDEX_FILES);
END {
        unlink keys %LOCKFILES if %LOCKFILES;
        unlink keys %INDEX_FILES if %INDEX_FILES;
}

sub resolve_local_globs {
        my ($url, $fetch, $glob_spec) = @_;
        return unless defined $glob_spec;
        my $ref = $glob_spec->{ref};
        my $path = $glob_spec->{path};
        foreach (command(qw#for-each-ref --format=%(refname) refs/#)) {
                next unless m#^$ref->{regex}$#;
                my $p = $1;
                my $pathname = desanitize_refname($path->full_path($p));
                my $refname = desanitize_refname($ref->full_path($p));
                if (my $existing = $fetch->{$pathname}) {
                        if ($existing ne $refname) {
                                die "Refspec conflict:\n",
                                    "existing: $existing\n",
                                    " globbed: $refname\n";
                        }
                        my $u = (::cmt_metadata("$refname"))[0];
                        $u =~ s!^\Q$url\E(/|$)!! or die
                          "$refname: '$url' not found in '$u'\n";
                        if ($pathname ne $u) {
                                warn "W: Refspec glob conflict ",
                                     "(ref: $refname):\n",
                                     "expected path: $pathname\n",
                                     "    real path: $u\n",
                                     "Continuing ahead with $u\n";
                                next;
                        }
                } else {
                        $fetch->{$pathname} = $refname;
                }
        }
}

sub parse_revision_argument {
        my ($base, $head) = @_;
        if (!defined $::_revision || $::_revision eq 'BASE:HEAD') {
                return ($base, $head);
        }
        return ($1, $2) if ($::_revision =~ /^(\d+):(\d+)$/);
        return ($::_revision, $::_revision) if ($::_revision =~ /^\d+$/);
        return ($head, $head) if ($::_revision eq 'HEAD');
        return ($base, $1) if ($::_revision =~ /^BASE:(\d+)$/);
        return ($1, $head) if ($::_revision =~ /^(\d+):HEAD$/);
        die "revision argument: $::_revision not understood by git-svn\n";
}

sub fetch_all {
        my ($repo_id, $remotes) = @_;
        if (ref $repo_id) {
                my $gs = $repo_id;
                $repo_id = undef;
                $repo_id = $gs->{repo_id};
        }
        $remotes ||= read_all_remotes();
        my $remote = $remotes->{$repo_id} or
                     die "[svn-remote \"$repo_id\"] unknown\n";
        my $fetch = $remote->{fetch};
        my $url = $remote->{url} or die "svn-remote.$repo_id.url not defined\n";
        my (@gs, @globs);
        my $ra = Git::SVN::Ra->new($url);
        my $uuid = $ra->get_uuid;
        my $head = $ra->get_latest_revnum;

        # ignore errors, $head revision may not even exist anymore
        eval { $ra->get_log("", $head, 0, 1, 0, 1, sub { $head = $_[1] }) };
        warn "W: $@\n" if $@;

        my $base = defined $fetch ? $head : 0;

        # read the max revs for wildcard expansion (branches/*, tags/*)
        foreach my $t (qw/branches tags/) {
                defined $remote->{$t} or next;
                push @globs, @{$remote->{$t}};

                my $max_rev = eval { tmp_config(qw/--int --get/,
                                         "svn-remote.$repo_id.${t}-maxRev") };
                if (defined $max_rev && ($max_rev < $base)) {
                        $base = $max_rev;
                } elsif (!defined $max_rev) {
                        $base = 0;
                }
        }

        if ($fetch) {
                foreach my $p (sort keys %$fetch) {
                        my $gs = Git::SVN->new($fetch->{$p}, $repo_id, $p);
                        my $lr = $gs->rev_map_max;
                        if (defined $lr) {
                                $base = $lr if ($lr < $base);
                        }
                        push @gs, $gs;
                }
        }

        ($base, $head) = parse_revision_argument($base, $head);
        $ra->gs_fetch_loop_common($base, $head, \@gs, \@globs);
}

sub read_all_remotes {
        my $r = {};
        my $use_svm_props = eval { command_oneline(qw/config --bool
            svn.useSvmProps/) };
        $use_svm_props = $use_svm_props eq 'true' if $use_svm_props;
        my $svn_refspec = qr{\s*(.*?)\s*:\s*(.+?)\s*};
        foreach (grep { s/^svn-remote\.// } command(qw/config -l/)) {
                if (m!^(.+)\.fetch=$svn_refspec$!) {
                        my ($remote, $local_ref, $remote_ref) = ($1, $2, $3);
                        die("svn-remote.$remote: remote ref '$remote_ref' "
                            . "must start with 'refs/'\n")
                                unless $remote_ref =~ m{^refs/};
                        $local_ref = uri_decode($local_ref);
                        $r->{$remote}->{fetch}->{$local_ref} = $remote_ref;
                        $r->{$remote}->{svm} = {} if $use_svm_props;
                } elsif (m!^(.+)\.usesvmprops=\s*(.*)\s*$!) {
                        $r->{$1}->{svm} = {};
                } elsif (m!^(.+)\.url=\s*(.*)\s*$!) {
                        $r->{$1}->{url} = $2;
                } elsif (m!^(.+)\.pushurl=\s*(.*)\s*$!) {
                        $r->{$1}->{pushurl} = $2;
                } elsif (m!^(.+)\.ignore-refs=\s*(.*)\s*$!) {
                        $r->{$1}->{ignore_refs_regex} = $2;
                } elsif (m!^(.+)\.(branches|tags)=$svn_refspec$!) {
                        my ($remote, $t, $local_ref, $remote_ref) =
                                                             ($1, $2, $3, $4);
                        die("svn-remote.$remote: remote ref '$remote_ref' ($t) "
                            . "must start with 'refs/'\n")
                                unless $remote_ref =~ m{^refs/};
                        $local_ref = uri_decode($local_ref);
                        my $rs = {
                            t => $t,
                            remote => $remote,
                            path => Git::SVN::GlobSpec->new($local_ref, 1),
                            ref => Git::SVN::GlobSpec->new($remote_ref, 0) };
                        if (length($rs->{ref}->{right}) != 0) {
                                die "The '*' glob character must be the last ",
                                    "character of '$remote_ref'\n";
                        }
                        push @{ $r->{$remote}->{$t} }, $rs;
                }
        }

        map {
                if (defined $r->{$_}->{svm}) {
                        my $svm;
                        eval {
                                my $section = "svn-remote.$_";
                                $svm = {
                                        source => tmp_config('--get',
                                            "$section.svm-source"),
                                        replace => tmp_config('--get',
                                            "$section.svm-replace"),
                                }
                        };
                        $r->{$_}->{svm} = $svm;
                }
        } keys %$r;

        foreach my $remote (keys %$r) {
                foreach ( grep { defined $_ }
                          map { $r->{$remote}->{$_} } qw(branches tags) ) {
                        foreach my $rs ( @$_ ) {
                                $rs->{ignore_refs_regex} =
                                    $r->{$remote}->{ignore_refs_regex};
                        }
                }
        }

        $r;
}

sub init_vars {
        $_gc_nr = $_gc_period = 1000;
        if (defined $_repack || defined $_repack_flags) {
               warn "Repack options are obsolete; they have no effect.\n";
        }
}

sub verify_remotes_sanity {
        return unless -d $ENV{GIT_DIR};
        my %seen;
        foreach (command(qw/config -l/)) {
                if (m!^svn-remote\.(?:.+)\.fetch=.*:refs/remotes/(\S+)\s*$!) {
                        if ($seen{$1}) {
                                die "Remote ref refs/remote/$1 is tracked by",
                                    "\n  \"$_\"\nand\n  \"$seen{$1}\"\n",
                                    "Please resolve this ambiguity in ",
                                    "your git configuration file before ",
                                    "continuing\n";
                        }
                        $seen{$1} = $_;
                }
        }
}

sub find_existing_remote {
        my ($url, $remotes) = @_;
        return undef if $no_reuse_existing;
        my $existing;
        foreach my $repo_id (keys %$remotes) {
                my $u = $remotes->{$repo_id}->{url} or next;
                next if $u ne $url;
                $existing = $repo_id;
                last;
        }
        $existing;
}

sub init_remote_config {
        my ($self, $url, $no_write) = @_;
        $url =~ s!/+$!!; # strip trailing slash
        my $r = read_all_remotes();
        my $existing = find_existing_remote($url, $r);
        if ($existing) {
                unless ($no_write) {
                        print STDERR "Using existing ",
                                     "[svn-remote \"$existing\"]\n";
                }
                $self->{repo_id} = $existing;
        } elsif ($_minimize_url) {
                my $min_url = Git::SVN::Ra->new($url)->minimize_url;
                $existing = find_existing_remote($min_url, $r);
                if ($existing) {
                        unless ($no_write) {
                                print STDERR "Using existing ",
                                             "[svn-remote \"$existing\"]\n";
                        }
                        $self->{repo_id} = $existing;
                }
                if ($min_url ne $url) {
                        unless ($no_write) {
                                print STDERR "Using higher level of URL: ",
                                             "$url => $min_url\n";
                        }
                        my $old_path = $self->{path};
                        $self->{path} = $url;
                        $self->{path} =~ s!^\Q$min_url\E(/|$)!!;
                        if (length $old_path) {
                                $self->{path} .= "/$old_path";
                        }
                        $url = $min_url;
                }
        }
        my $orig_url;
        if (!$existing) {
                # verify that we aren't overwriting anything:
                $orig_url = eval {
                        command_oneline('config', '--get',
                                        "svn-remote.$self->{repo_id}.url")
                };
                if ($orig_url && ($orig_url ne $url)) {
                        die "svn-remote.$self->{repo_id}.url already set: ",
                            "$orig_url\nwanted to set to: $url\n";
                }
        }
        my ($xrepo_id, $xpath) = find_ref($self->refname);
        if (!$no_write && defined $xpath) {
                die "svn-remote.$xrepo_id.fetch already set to track ",
                    "$xpath:", $self->refname, "\n";
        }
        unless ($no_write) {
                command_noisy('config',
                              "svn-remote.$self->{repo_id}.url", $url);
                $self->{path} =~ s{^/}{};
                $self->{path} =~ s{%([0-9A-F]{2})}{chr hex($1)}ieg;
                command_noisy('config', '--add',
                              "svn-remote.$self->{repo_id}.fetch",
                              "$self->{path}:".$self->refname);
        }
        $self->{url} = $url;
}

sub find_by_url { # repos_root and, path are optional
        my ($class, $full_url, $repos_root, $path) = @_;

        return undef unless defined $full_url;
        remove_username($full_url);
        remove_username($repos_root) if defined $repos_root;
        my $remotes = read_all_remotes();
        if (defined $full_url && defined $repos_root && !defined $path) {
                $path = $full_url;
                $path =~ s#^\Q$repos_root\E(?:/|$)##;
        }
        foreach my $repo_id (keys %$remotes) {
                my $u = $remotes->{$repo_id}->{url} or next;
                remove_username($u);
                next if defined $repos_root && $repos_root ne $u;

                my $fetch = $remotes->{$repo_id}->{fetch} || {};
                foreach my $t (qw/branches tags/) {
                        foreach my $globspec (@{$remotes->{$repo_id}->{$t}}) {
                                resolve_local_globs($u, $fetch, $globspec);
                        }
                }
                my $p = $path;
                my $rwr = rewrite_root({repo_id => $repo_id});
                my $svm = $remotes->{$repo_id}->{svm}
                        if defined $remotes->{$repo_id}->{svm};
                unless (defined $p) {
                        $p = $full_url;
                        my $z = $u;
                        my $prefix = '';
                        if ($rwr) {
                                $z = $rwr;
                                remove_username($z);
                        } elsif (defined $svm) {
                                $z = $svm->{source};
                                $prefix = $svm->{replace};
                                $prefix =~ s#^\Q$u\E(?:/|$)##;
                                $prefix =~ s#/$##;
                        }
                        $p =~ s#^\Q$z\E(?:/|$)#$prefix# or next;
                }
                foreach my $f (keys %$fetch) {
                        next if $f ne $p;
                        return Git::SVN->new($fetch->{$f}, $repo_id, $f);
                }
        }
        undef;
}

sub init {
        my ($class, $url, $path, $repo_id, $ref_id, $no_write) = @_;
        my $self = _new($class, $repo_id, $ref_id, $path);
        if (defined $url) {
                $self->init_remote_config($url, $no_write);
        }
        $self;
}

sub find_ref {
        my ($ref_id) = @_;
        foreach (command(qw/config -l/)) {
                next unless m!^svn-remote\.(.+)\.fetch=
                              \s*(.*?)\s*:\s*(.+?)\s*$!x;
                my ($repo_id, $path, $ref) = ($1, $2, $3);
                if ($ref eq $ref_id) {
                        $path = '' if ($path =~ m#^\./?#);
                        return ($repo_id, $path);
                }
        }
        (undef, undef, undef);
}

sub new {
        my ($class, $ref_id, $repo_id, $path) = @_;
        if (defined $ref_id && !defined $repo_id && !defined $path) {
                ($repo_id, $path) = find_ref($ref_id);
                if (!defined $repo_id) {
                        die "Could not find a \"svn-remote.*.fetch\" key ",
                            "in the repository configuration matching: ",
                            "$ref_id\n";
                }
        }
        my $self = _new($class, $repo_id, $ref_id, $path);
        if (!defined $self->{path} || !length $self->{path}) {
                my $fetch = command_oneline('config', '--get',
                                            "svn-remote.$repo_id.fetch",
                                            ":$ref_id\$") or
                     die "Failed to read \"svn-remote.$repo_id.fetch\" ",
                         "\":$ref_id\$\" in config\n";
                ($self->{path}, undef) = split(/\s*:\s*/, $fetch);
        }
        $self->{path} =~ s{/+}{/}g;
        $self->{path} =~ s{\A/}{};
        $self->{path} =~ s{/\z}{};
        $self->{url} = command_oneline('config', '--get',
                                       "svn-remote.$repo_id.url") or
                  die "Failed to read \"svn-remote.$repo_id.url\" in config\n";
        $self->{pushurl} = eval { command_oneline('config', '--get',
                                  "svn-remote.$repo_id.pushurl") };
        $self->rebuild;
        $self;
}

sub refname {
        my ($refname) = $_[0]->{ref_id} ;

        # It cannot end with a slash /, we'll throw up on this because
        # SVN can't have directories with a slash in their name, either:
        if ($refname =~ m{/$}) {
                die "ref: '$refname' ends with a trailing slash, this is ",
                    "not permitted by git nor Subversion\n";
        }

        # It cannot have ASCII control character space, tilde ~, caret ^,
        # colon :, question-mark ?, asterisk *, space, or open bracket [
        # anywhere.
        #
        # Additionally, % must be escaped because it is used for escaping
        # and we want our escaped refname to be reversible
        $refname =~ s{([ \%~\^:\?\*\[\t])}{uc sprintf('%%%02x',ord($1))}eg;

        # no slash-separated component can begin with a dot .
        # /.* becomes /%2E*
        $refname =~ s{/\.}{/%2E}g;

        # It cannot have two consecutive dots .. anywhere
        # .. becomes %2E%2E
        $refname =~ s{\.\.}{%2E%2E}g;

        # trailing dots and .lock are not allowed
        # .$ becomes %2E and .lock becomes %2Elock
        $refname =~ s{\.(?=$|lock$)}{%2E};

        # the sequence @{ is used to access the reflog
        # @{ becomes %40{
        $refname =~ s{\@\{}{%40\{}g;

        return $refname;
}

sub desanitize_refname {
        my ($refname) = @_;
        $refname =~ s{%(?:([0-9A-F]{2}))}{chr hex($1)}eg;
        return $refname;
}

sub svm_uuid {
        my ($self) = @_;
        return $self->{svm}->{uuid} if $self->svm;
        $self->ra;
        unless ($self->{svm}) {
                die "SVM UUID not cached, and reading remotely failed\n";
        }
        $self->{svm}->{uuid};
}

sub svm {
        my ($self) = @_;
        return $self->{svm} if $self->{svm};
        my $svm;
        # see if we have it in our config, first:
        eval {
                my $section = "svn-remote.$self->{repo_id}";
                $svm = {
                  source => tmp_config('--get', "$section.svm-source"),
                  uuid => tmp_config('--get', "$section.svm-uuid"),
                  replace => tmp_config('--get', "$section.svm-replace"),
                }
        };
        if ($svm && $svm->{source} && $svm->{uuid} && $svm->{replace}) {
                $self->{svm} = $svm;
        }
        $self->{svm};
}

sub _set_svm_vars {
        my ($self, $ra) = @_;
        return $ra if $self->svm;

        my @err = ( "useSvmProps set, but failed to read SVM properties\n",
                    "(svm:source, svm:uuid) ",
                    "from the following URLs:\n" );
        sub read_svm_props {
                my ($self, $ra, $path, $r) = @_;
                my $props = ($ra->get_dir($path, $r))[2];
                my $src = $props->{'svm:source'};
                my $uuid = $props->{'svm:uuid'};
                return undef if (!$src || !$uuid);

                chomp($src, $uuid);

                $uuid =~ m{^[0-9a-f\-]{30,}$}i
                    or die "doesn't look right - svm:uuid is '$uuid'\n";

                # the '!' is used to mark the repos_root!/relative/path
                $src =~ s{/?!/?}{/};
                $src =~ s{/+$}{}; # no trailing slashes please
                # username is of no interest
                $src =~ s{(^[a-z\+]*://)[^/@]*@}{$1};

                my $replace = $ra->{url};
                $replace .= "/$path" if length $path;

                my $section = "svn-remote.$self->{repo_id}";
                tmp_config("$section.svm-source", $src);
                tmp_config("$section.svm-replace", $replace);
                tmp_config("$section.svm-uuid", $uuid);
                $self->{svm} = {
                        source => $src,
                        uuid => $uuid,
                        replace => $replace
                };
        }

        my $r = $ra->get_latest_revnum;
        my $path = $self->{path};
        my %tried;
        while (length $path) {
                unless ($tried{"$self->{url}/$path"}) {
                        return $ra if $self->read_svm_props($ra, $path, $r);
                        $tried{"$self->{url}/$path"} = 1;
                }
                $path =~ s#/?[^/]+$##;
        }
        die "Path: '$path' should be ''\n" if $path ne '';
        return $ra if $self->read_svm_props($ra, $path, $r);
        $tried{"$self->{url}/$path"} = 1;

        if ($ra->{repos_root} eq $self->{url}) {
                die @err, (map { "  $_\n" } keys %tried), "\n";
        }

        # nope, make sure we're connected to the repository root:
        my $ok;
        my @tried_b;
        $path = $ra->{svn_path};
        $ra = Git::SVN::Ra->new($ra->{repos_root});
        while (length $path) {
                unless ($tried{"$ra->{url}/$path"}) {
                        $ok = $self->read_svm_props($ra, $path, $r);
                        last if $ok;
                        $tried{"$ra->{url}/$path"} = 1;
                }
                $path =~ s#/?[^/]+$##;
        }
        die "Path: '$path' should be ''\n" if $path ne '';
        $ok ||= $self->read_svm_props($ra, $path, $r);
        $tried{"$ra->{url}/$path"} = 1;
        if (!$ok) {
                die @err, (map { "  $_\n" } keys %tried), "\n";
        }
        Git::SVN::Ra->new($self->{url});
}

sub svnsync {
        my ($self) = @_;
        return $self->{svnsync} if $self->{svnsync};

        if ($self->no_metadata) {
                die "Can't have both 'noMetadata' and ",
                    "'useSvnsyncProps' options set!\n";
        }
        if ($self->rewrite_root) {
                die "Can't have both 'useSvnsyncProps' and 'rewriteRoot' ",
                    "options set!\n";
        }
        if ($self->rewrite_uuid) {
                die "Can't have both 'useSvnsyncProps' and 'rewriteUUID' ",
                    "options set!\n";
        }

        my $svnsync;
        # see if we have it in our config, first:
        eval {
                my $section = "svn-remote.$self->{repo_id}";

                my $url = tmp_config('--get', "$section.svnsync-url");
                ($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
                   die "doesn't look right - svn:sync-from-url is '$url'\n";

                my $uuid = tmp_config('--get', "$section.svnsync-uuid");
                ($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
                   die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";

                $svnsync = { url => $url, uuid => $uuid }
        };
        if ($svnsync && $svnsync->{url} && $svnsync->{uuid}) {
                return $self->{svnsync} = $svnsync;
        }

        my $err = "useSvnsyncProps set, but failed to read " .
                  "svnsync property: svn:sync-from-";
        my $rp = $self->ra->rev_proplist(0);

        my $url = $rp->{'svn:sync-from-url'} or die $err . "url\n";
        ($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
                   die "doesn't look right - svn:sync-from-url is '$url'\n";

        my $uuid = $rp->{'svn:sync-from-uuid'} or die $err . "uuid\n";
        ($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
                   die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";

        my $section = "svn-remote.$self->{repo_id}";
        tmp_config('--add', "$section.svnsync-uuid", $uuid);
        tmp_config('--add', "$section.svnsync-url", $url);
        return $self->{svnsync} = { url => $url, uuid => $uuid };
}

# this allows us to memoize our SVN::Ra UUID locally and avoid a
# remote lookup (useful for 'git svn log').
sub ra_uuid {
        my ($self) = @_;
        unless ($self->{ra_uuid}) {
                my $key = "svn-remote.$self->{repo_id}.uuid";
                my $uuid = eval { tmp_config('--get', $key) };
                if (!$@ && $uuid && $uuid =~ /^([a-f\d\-]{30,})$/i) {
                        $self->{ra_uuid} = $uuid;
                } else {
                        die "ra_uuid called without URL\n" unless $self->{url};
                        $self->{ra_uuid} = $self->ra->get_uuid;
                        tmp_config('--add', $key, $self->{ra_uuid});
                }
        }
        $self->{ra_uuid};
}

sub _set_repos_root {
        my ($self, $repos_root) = @_;
        my $k = "svn-remote.$self->{repo_id}.reposRoot";
        $repos_root ||= $self->ra->{repos_root};
        tmp_config($k, $repos_root);
        $repos_root;
}

sub repos_root {
        my ($self) = @_;
        my $k = "svn-remote.$self->{repo_id}.reposRoot";
        eval { tmp_config('--get', $k) } || $self->_set_repos_root;
}

sub ra {
        my ($self) = shift;
        my $ra = Git::SVN::Ra->new($self->{url});
        $self->_set_repos_root($ra->{repos_root});
        if ($self->use_svm_props && !$self->{svm}) {
                if ($self->no_metadata) {
                        die "Can't have both 'noMetadata' and ",
                            "'useSvmProps' options set!\n";
                } elsif ($self->use_svnsync_props) {
                        die "Can't have both 'useSvnsyncProps' and ",
                            "'useSvmProps' options set!\n";
                }
                $ra = $self->_set_svm_vars($ra);
                $self->{-want_revprops} = 1;
        }
        $ra;
}

# prop_walk(PATH, REV, SUB)
# -------------------------
# Recursively traverse PATH at revision REV and invoke SUB for each
# directory that contains a SVN property.  SUB will be invoked as
# follows:  &SUB(gs, path, props);  where `gs' is this instance of
# Git::SVN, `path' the path to the directory where the properties
# `props' were found.  The `path' will be relative to point of checkout,
# that is, if url://repo/trunk is the current Git branch, and that
# directory contains a sub-directory `d', SUB will be invoked with `/d/'
# as `path' (note the trailing `/').
sub prop_walk {
        my ($self, $path, $rev, $sub) = @_;

        $path =~ s#^/##;
        my ($dirent, undef, $props) = $self->ra->get_dir($path, $rev);
        $path =~ s#^/*#/#g;
        my $p = $path;
        # Strip the irrelevant part of the path.
        $p =~ s#^/+\Q$self->{path}\E(/|$)#/#;
        # Ensure the path is terminated by a `/'.
        $p =~ s#/*$#/#;

        # The properties contain all the internal SVN stuff nobody
        # (usually) cares about.
        my $interesting_props = 0;
        foreach (keys %{$props}) {
                # If it doesn't start with `svn:', it must be a
                # user-defined property.
                ++$interesting_props and next if $_ !~ /^svn:/;
                # FIXME: Fragile, if SVN adds new public properties,
                # this needs to be updated.
                ++$interesting_props if /^svn:(?:ignore|keywords|executable
                                                 |eol-style|mime-type
                                                 |externals|needs-lock)$/x;
        }
        &$sub($self, $p, $props) if $interesting_props;

        foreach (sort keys %$dirent) {
                next if $dirent->{$_}->{kind} != $SVN::Node::dir;
                $self->prop_walk($self->{path} . $p . $_, $rev, $sub);
        }
}

sub last_rev { ($_[0]->last_rev_commit)[0] }
sub last_commit { ($_[0]->last_rev_commit)[1] }

# returns the newest SVN revision number and newest commit SHA1
sub last_rev_commit {
        my ($self) = @_;
        if (defined $self->{last_rev} && defined $self->{last_commit}) {
                return ($self->{last_rev}, $self->{last_commit});
        }
        my $c = ::verify_ref($self->refname.'^0');
        if ($c && !$self->use_svm_props && !$self->no_metadata) {
                my $rev = (::cmt_metadata($c))[1];
                if (defined $rev) {
                        ($self->{last_rev}, $self->{last_commit}) = ($rev, $c);
                        return ($rev, $c);
                }
        }
        my $map_path = $self->map_path;
        unless (-e $map_path) {
                ($self->{last_rev}, $self->{last_commit}) = (undef, undef);
                return (undef, undef);
        }
        my ($rev, $commit) = $self->rev_map_max(1);
        ($self->{last_rev}, $self->{last_commit}) = ($rev, $commit);
        return ($rev, $commit);
}

sub get_fetch_range {
        my ($self, $min, $max) = @_;
        $max ||= $self->ra->get_latest_revnum;
        $min ||= $self->rev_map_max;
        (++$min, $max);
}

sub tmp_config {
        my (@args) = @_;
        my $old_def_config = "$ENV{GIT_DIR}/svn/config";
        my $config = "$ENV{GIT_DIR}/svn/.metadata";
        if (! -f $config && -f $old_def_config) {
                rename $old_def_config, $config or
                       die "Failed rename $old_def_config => $config: $!\n";
        }
        my $old_config = $ENV{GIT_CONFIG};
        $ENV{GIT_CONFIG} = $config;
        $@ = undef;
        my @ret = eval {
                unless (-f $config) {
                        mkfile($config);
                        open my $fh, '>', $config or
                            die "Can't open $config: $!\n";
                        print $fh "; This file is used internally by ",
                                  "git-svn\n" or die
                                  "Couldn't write to $config: $!\n";
                        print $fh "; You should not have to edit it\n" or
                              die "Couldn't write to $config: $!\n";
                        close $fh or die "Couldn't close $config: $!\n";
                }
                command('config', @args);
        };
        my $err = $@;
        if (defined $old_config) {
                $ENV{GIT_CONFIG} = $old_config;
        } else {
                delete $ENV{GIT_CONFIG};
        }
        die $err if $err;
        wantarray ? @ret : $ret[0];
}

sub tmp_index_do {
        my ($self, $sub) = @_;
        my $old_index = $ENV{GIT_INDEX_FILE};
        $ENV{GIT_INDEX_FILE} = $self->{index};
        $@ = undef;
        my @ret = eval {
                my ($dir, $base) = ($self->{index} =~ m#^(.*?)/?([^/]+)$#);
                mkpath([$dir]) unless -d $dir;
                &$sub;
        };
        my $err = $@;
        if (defined $old_index) {
                $ENV{GIT_INDEX_FILE} = $old_index;
        } else {
                delete $ENV{GIT_INDEX_FILE};
        }
        die $err if $err;
        wantarray ? @ret : $ret[0];
}

sub assert_index_clean {
        my ($self, $treeish) = @_;

        $self->tmp_index_do(sub {
                command_noisy('read-tree', $treeish) unless -e $self->{index};
                my $x = command_oneline('write-tree');
                my ($y) = (command(qw/cat-file commit/, $treeish) =~
                           /^tree ($::sha1)/mo);
                return if $y eq $x;

                warn "Index mismatch: $y != $x\nrereading $treeish\n";
                unlink $self->{index} or die "unlink $self->{index}: $!\n";
                command_noisy('read-tree', $treeish);
                $x = command_oneline('write-tree');
                if ($y ne $x) {
                        fatal "trees ($treeish) $y != $x\n",
                              "Something is seriously wrong...";
                }
        });
}

sub get_commit_parents {
        my ($self, $log_entry) = @_;
        my (%seen, @ret, @tmp);
        # legacy support for 'set-tree'; this is only used by set_tree_cb:
        if (my $ip = $self->{inject_parents}) {
                if (my $commit = delete $ip->{$log_entry->{revision}}) {
                        push @tmp, $commit;
                }
        }
        if (my $cur = ::verify_ref($self->refname.'^0')) {
                push @tmp, $cur;
        }
        if (my $ipd = $self->{inject_parents_dcommit}) {
                if (my $commit = delete $ipd->{$log_entry->{revision}}) {
                        push @tmp, @$commit;
                }
        }
        push @tmp, $_ foreach (@{$log_entry->{parents}}, @tmp);
        while (my $p = shift @tmp) {
                next if $seen{$p};
                $seen{$p} = 1;
                push @ret, $p;
        }
        @ret;
}

sub rewrite_root {
        my ($self) = @_;
        return $self->{-rewrite_root} if exists $self->{-rewrite_root};
        my $k = "svn-remote.$self->{repo_id}.rewriteRoot";
        my $rwr = eval { command_oneline(qw/config --get/, $k) };
        if ($rwr) {
                $rwr =~ s#/+$##;
                if ($rwr !~ m#^[a-z\+]+://#) {
                        die "$rwr is not a valid URL (key: $k)\n";
                }
        }
        $self->{-rewrite_root} = $rwr;
}

sub rewrite_uuid {
        my ($self) = @_;
        return $self->{-rewrite_uuid} if exists $self->{-rewrite_uuid};
        my $k = "svn-remote.$self->{repo_id}.rewriteUUID";
        my $rwid = eval { command_oneline(qw/config --get/, $k) };
        if ($rwid) {
                $rwid =~ s#/+$##;
                if ($rwid !~ m#^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}$#) {
                        die "$rwid is not a valid UUID (key: $k)\n";
                }
        }
        $self->{-rewrite_uuid} = $rwid;
}

sub metadata_url {
        my ($self) = @_;
        ($self->rewrite_root || $self->{url}) .
           (length $self->{path} ? '/' . $self->{path} : '');
}

sub full_url {
        my ($self) = @_;
        $self->{url} . (length $self->{path} ? '/' . $self->{path} : '');
}

sub full_pushurl {
        my ($self) = @_;
        if ($self->{pushurl}) {
                return $self->{pushurl} . (length $self->{path} ? '/' .
                       $self->{path} : '');
        } else {
                return $self->full_url;
        }
}

sub set_commit_header_env {
        my ($log_entry) = @_;
        my %env;
        foreach my $ned (qw/NAME EMAIL DATE/) {
                foreach my $ac (qw/AUTHOR COMMITTER/) {
                        $env{"GIT_${ac}_${ned}"} = $ENV{"GIT_${ac}_${ned}"};
                }
        }

        $ENV{GIT_AUTHOR_NAME} = $log_entry->{name};
        $ENV{GIT_AUTHOR_EMAIL} = $log_entry->{email};
        $ENV{GIT_AUTHOR_DATE} = $ENV{GIT_COMMITTER_DATE} = $log_entry->{date};

        $ENV{GIT_COMMITTER_NAME} = (defined $log_entry->{commit_name})
                                                ? $log_entry->{commit_name}
                                                : $log_entry->{name};
        $ENV{GIT_COMMITTER_EMAIL} = (defined $log_entry->{commit_email})
                                                ? $log_entry->{commit_email}
                                                : $log_entry->{email};
        \%env;
}

sub restore_commit_header_env {
        my ($env) = @_;
        foreach my $ned (qw/NAME EMAIL DATE/) {
                foreach my $ac (qw/AUTHOR COMMITTER/) {
                        my $k = "GIT_${ac}_${ned}";
                        if (defined $env->{$k}) {
                                $ENV{$k} = $env->{$k};
                        } else {
                                delete $ENV{$k};
                        }
                }
        }
}

sub gc {
        command_noisy('gc', '--auto');
};

sub do_git_commit {
        my ($self, $log_entry) = @_;
        my $lr = $self->last_rev;
        if (defined $lr && $lr >= $log_entry->{revision}) {
                die "Last fetched revision of ", $self->refname,
                    " was r$lr, but we are about to fetch: ",
                    "r$log_entry->{revision}!\n";
        }
        if (my $c = $self->rev_map_get($log_entry->{revision})) {
                croak "$log_entry->{revision} = $c already exists! ",
                      "Why are we refetching it?\n";
        }
        my $old_env = set_commit_header_env($log_entry);
        my $tree = $log_entry->{tree};
        if (!defined $tree) {
                $tree = $self->tmp_index_do(sub {
                                            command_oneline('write-tree') });
        }
        die "Tree is not a valid sha1: $tree\n" if $tree !~ /^$::sha1$/o;

        my @exec = ('git', 'commit-tree', $tree);
        foreach ($self->get_commit_parents($log_entry)) {
                push @exec, '-p', $_;
        }
        defined(my $pid = open3(my $msg_fh, my $out_fh, '>&STDERR', @exec))
                                                                   or croak $!;
        binmode $msg_fh;

        # we always get UTF-8 from SVN, but we may want our commits in
        # a different encoding.
        if (my $enc = Git::config('i18n.commitencoding')) {
                require Encode;
                Encode::from_to($log_entry->{log}, 'UTF-8', $enc);
        }
        print $msg_fh $log_entry->{log} or croak $!;
        restore_commit_header_env($old_env);
        unless ($self->no_metadata) {
                print $msg_fh "\ngit-svn-id: $log_entry->{metadata}\n"
                              or croak $!;
        }
        $msg_fh->flush == 0 or croak $!;
        close $msg_fh or croak $!;
        chomp(my $commit = do { local $/; <$out_fh> });
        close $out_fh or croak $!;
        waitpid $pid, 0;
        croak $? if $?;
        if ($commit !~ /^$::sha1$/o) {
                die "Failed to commit, invalid sha1: $commit\n";
        }

        $self->rev_map_set($log_entry->{revision}, $commit, 1);

        $self->{last_rev} = $log_entry->{revision};
        $self->{last_commit} = $commit;
        print "r$log_entry->{revision}" unless $::_q > 1;
        if (defined $log_entry->{svm_revision}) {
                 print " (\@$log_entry->{svm_revision})" unless $::_q > 1;
                 $self->rev_map_set($log_entry->{svm_revision}, $commit,
                                   0, $self->svm_uuid);
        }
        print " = $commit ($self->{ref_id})\n" unless $::_q > 1;
        if (--$_gc_nr == 0) {
                $_gc_nr = $_gc_period;
                gc();
        }
        return $commit;
}

sub match_paths {
        my ($self, $paths, $r) = @_;
        return 1 if $self->{path} eq '';
        if (my $path = $paths->{"/$self->{path}"}) {
                return ($path->{action} eq 'D') ? 0 : 1;
        }
        $self->{path_regex} ||= qr/^\/\Q$self->{path}\E\//;
        if (grep /$self->{path_regex}/, keys %$paths) {
                return 1;
        }
        my $c = '';
        foreach (split m#/#, $self->{path}) {
                $c .= "/$_";
                next unless ($paths->{$c} &&
                             ($paths->{$c}->{action} =~ /^[AR]$/));
                if ($self->ra->check_path($self->{path}, $r) ==
                    $SVN::Node::dir) {
                        return 1;
                }
        }
        return 0;
}

sub find_parent_branch {
        my ($self, $paths, $rev) = @_;
        return undef unless $self->follow_parent;
        unless (defined $paths) {
                my $err_handler = $SVN::Error::handler;
                $SVN::Error::handler = \&Git::SVN::Ra::skip_unknown_revs;
                $self->ra->get_log([$self->{path}], $rev, $rev, 0, 1, 1,
                                   sub { $paths = $_[0] });
                $SVN::Error::handler = $err_handler;
        }
        return undef unless defined $paths;

        # look for a parent from another branch:
        my @b_path_components = split m#/#, $self->{path};
        my @a_path_components;
        my $i;
        while (@b_path_components) {
                $i = $paths->{'/'.join('/', @b_path_components)};
                last if $i && defined $i->{copyfrom_path};
                unshift(@a_path_components, pop(@b_path_components));
        }
        return undef unless defined $i && defined $i->{copyfrom_path};
        my $branch_from = $i->{copyfrom_path};
        if (@a_path_components) {
                print STDERR "branch_from: $branch_from => ";
                $branch_from .= '/'.join('/', @a_path_components);
                print STDERR $branch_from, "\n";
        }
        my $r = $i->{copyfrom_rev};
        my $repos_root = $self->ra->{repos_root};
        my $url = $self->ra->{url};
        my $new_url = $url . $branch_from;
        print STDERR  "Found possible branch point: ",
                      "$new_url => ", $self->full_url, ", $r\n"
                      unless $::_q > 1;
        $branch_from =~ s#^/##;
        my $gs = $self->other_gs($new_url, $url,
                                 $branch_from, $r, $self->{ref_id});
        my ($r0, $parent) = $gs->find_rev_before($r, 1);
        {
                my ($base, $head);
                if (!defined $r0 || !defined $parent) {
                        ($base, $head) = parse_revision_argument(0, $r);
                } else {
                        if ($r0 < $r) {
                                $gs->ra->get_log([$gs->{path}], $r0 + 1, $r, 1,
                                        0, 1, sub { $base = $_[1] - 1 });
                        }
                }
                if (defined $base && $base <= $r) {
                        $gs->fetch($base, $r);
                }
                ($r0, $parent) = $gs->find_rev_before($r, 1);
        }
        if (defined $r0 && defined $parent) {
                print STDERR "Found branch parent: ($self->{ref_id}) $parent\n"
                             unless $::_q > 1;
                my $ed;
                if ($self->ra->can_do_switch) {
                        $self->assert_index_clean($parent);
                        print STDERR "Following parent with do_switch\n"
                                     unless $::_q > 1;
                        # do_switch works with svn/trunk >= r22312, but that
                        # is not included with SVN 1.4.3 (the latest version
                        # at the moment), so we can't rely on it
                        $self->{last_rev} = $r0;
                        $self->{last_commit} = $parent;
                        $ed = Git::SVN::Fetcher->new($self, $gs->{path});
                        $gs->ra->gs_do_switch($r0, $rev, $gs,
                                              $self->full_url, $ed)
                          or die "SVN connection failed somewhere...\n";
                } elsif ($self->ra->trees_match($new_url, $r0,
                                                $self->full_url, $rev)) {
                        print STDERR "Trees match:\n",
                                     "  $new_url\@$r0\n",
                                     "  ${\$self->full_url}\@$rev\n",
                                     "Following parent with no changes\n"
                                     unless $::_q > 1;
                        $self->tmp_index_do(sub {
                            command_noisy('read-tree', $parent);
                        });
                        $self->{last_commit} = $parent;
                } else {
                        print STDERR "Following parent with do_update\n"
                                     unless $::_q > 1;
                        $ed = Git::SVN::Fetcher->new($self);
                        $self->ra->gs_do_update($rev, $rev, $self, $ed)
                          or die "SVN connection failed somewhere...\n";
                }
                print STDERR "Successfully followed parent\n" unless $::_q > 1;
                return $self->make_log_entry($rev, [$parent], $ed);
        }
        return undef;
}

sub do_fetch {
        my ($self, $paths, $rev) = @_;
        my $ed;
        my ($last_rev, @parents);
        if (my $lc = $self->last_commit) {
                # we can have a branch that was deleted, then re-added
                # under the same name but copied from another path, in
                # which case we'll have multiple parents (we don't
                # want to break the original ref, nor lose copypath info):
                if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
                        push @{$log_entry->{parents}}, $lc;
                        return $log_entry;
                }
                $ed = Git::SVN::Fetcher->new($self);
                $last_rev = $self->{last_rev};
                $ed->{c} = $lc;
                @parents = ($lc);
        } else {
                $last_rev = $rev;
                if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
                        return $log_entry;
                }
                $ed = Git::SVN::Fetcher->new($self);
        }
        unless ($self->ra->gs_do_update($last_rev, $rev, $self, $ed)) {
                die "SVN connection failed somewhere...\n";
        }
        $self->make_log_entry($rev, \@parents, $ed);
}

sub mkemptydirs {
        my ($self, $r) = @_;

        sub scan {
                my ($r, $empty_dirs, $line) = @_;
                if (defined $r && $line =~ /^r(\d+)$/) {
                        return 0 if $1 > $r;
                } elsif ($line =~ /^  \+empty_dir: (.+)$/) {
                        $empty_dirs->{$1} = 1;
                } elsif ($line =~ /^  \-empty_dir: (.+)$/) {
                        my @d = grep {m[^\Q$1\E(/|$)]} (keys %$empty_dirs);
                        delete @$empty_dirs{@d};
                }
                1; # continue
        };

        my %empty_dirs = ();
        my $gz_file = "$self->{dir}/unhandled.log.gz";
        if (-f $gz_file) {
                if (!can_compress()) {
                        warn "Compress::Zlib could not be found; ",
                             "empty directories in $gz_file will not be read\n";
                } else {
                        my $gz = Compress::Zlib::gzopen($gz_file, "rb") or
                                die "Unable to open $gz_file: $!\n";
                        my $line;
                        while ($gz->gzreadline($line) > 0) {
                                scan($r, \%empty_dirs, $line) or last;
                        }
                        $gz->gzclose;
                }
        }

        if (open my $fh, '<', "$self->{dir}/unhandled.log") {
                binmode $fh or croak "binmode: $!";
                while (<$fh>) {
                        scan($r, \%empty_dirs, $_) or last;
                }
                close $fh;
        }

        my $strip = qr/\A\Q$self->{path}\E(?:\/|$)/;
        foreach my $d (sort keys %empty_dirs) {
                $d = uri_decode($d);
                $d =~ s/$strip//;
                next unless length($d);
                next if -d $d;
                if (-e $d) {
                        warn "$d exists but is not a directory\n";
                } else {
                        print "creating empty directory: $d\n";
                        mkpath([$d]);
                }
        }
}

sub get_untracked {
        my ($self, $ed) = @_;
        my @out;
        my $h = $ed->{empty};
        foreach (sort keys %$h) {
                my $act = $h->{$_} ? '+empty_dir' : '-empty_dir';
                push @out, "  $act: " . uri_encode($_);
                warn "W: $act: $_\n";
        }
        foreach my $t (qw/dir_prop file_prop/) {
                $h = $ed->{$t} or next;
                foreach my $path (sort keys %$h) {
                        my $ppath = $path eq '' ? '.' : $path;
                        foreach my $prop (sort keys %{$h->{$path}}) {
                                next if $SKIP_PROP{$prop};
                                my $v = $h->{$path}->{$prop};
                                my $t_ppath_prop = "$t: " .
                                                    uri_encode($ppath) . ' ' .
                                                    uri_encode($prop);
                                if (defined $v) {
                                        push @out, "  +$t_ppath_prop " .
                                                   uri_encode($v);
                                } else {
                                        push @out, "  -$t_ppath_prop";
                                }
                        }
                }
        }
        foreach my $t (qw/absent_file absent_directory/) {
                $h = $ed->{$t} or next;
                foreach my $parent (sort keys %$h) {
                        foreach my $path (sort @{$h->{$parent}}) {
                                push @out, "  $t: " .
                                           uri_encode("$parent/$path");
                                warn "W: $t: $parent/$path ",
                                     "Insufficient permissions?\n";
                        }
                }
        }
        \@out;
}

sub get_tz {
        # some systmes don't handle or mishandle %z, so be creative.
        my $t = shift || time;
        my $gm = timelocal(gmtime($t));
        my $sign = qw( + + - )[ $t <=> $gm ];
        return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
}

# parse_svn_date(DATE)
# --------------------
# Given a date (in UTC) from Subversion, return a string in the format
# "<TZ Offset> <local date/time>" that Git will use.
#
# By default the parsed date will be in UTC; if $Git::SVN::_localtime
# is true we'll convert it to the local timezone instead.
sub parse_svn_date {
        my $date = shift || return '+0000 1970-01-01 00:00:00';
        my ($Y,$m,$d,$H,$M,$S) = ($date =~ /^(\d{4})\-(\d\d)\-(\d\d)T
                                            (\d\d)\:(\d\d)\:(\d\d)\.\d*Z$/x) or
                                         croak "Unable to parse date: $date\n";
        my $parsed_date;    # Set next.

        if ($Git::SVN::_localtime) {
                # Translate the Subversion datetime to an epoch time.
                # Begin by switching ourselves to $date's timezone, UTC.
                my $old_env_TZ = $ENV{TZ};
                $ENV{TZ} = 'UTC';

                my $epoch_in_UTC =
                    POSIX::strftime('%s', $S, $M, $H, $d, $m - 1, $Y - 1900);

                # Determine our local timezone (including DST) at the
                # time of $epoch_in_UTC.  $Git::SVN::Log::TZ stored the
                # value of TZ, if any, at the time we were run.
                if (defined $Git::SVN::Log::TZ) {
                        $ENV{TZ} = $Git::SVN::Log::TZ;
                } else {
                        delete $ENV{TZ};
                }

                my $our_TZ = get_tz();

                # This converts $epoch_in_UTC into our local timezone.
                my ($sec, $min, $hour, $mday, $mon, $year,
                    $wday, $yday, $isdst) = localtime($epoch_in_UTC);

                $parsed_date = sprintf('%s %04d-%02d-%02d %02d:%02d:%02d',
                                       $our_TZ, $year + 1900, $mon + 1,
                                       $mday, $hour, $min, $sec);

                # Reset us to the timezone in effect when we entered
                # this routine.
                if (defined $old_env_TZ) {
                        $ENV{TZ} = $old_env_TZ;
                } else {
                        delete $ENV{TZ};
                }
        } else {
                $parsed_date = "+0000 $Y-$m-$d $H:$M:$S";
        }

        return $parsed_date;
}

sub other_gs {
        my ($self, $new_url, $url,
            $branch_from, $r, $old_ref_id) = @_;
        my $gs = Git::SVN->find_by_url($new_url, $url, $branch_from);
        unless ($gs) {
                my $ref_id = $old_ref_id;
                $ref_id =~ s/\@\d+-*$//;
                $ref_id .= "\@$r";
                # just grow a tail if we're not unique enough :x
                $ref_id .= '-' while find_ref($ref_id);
                my ($u, $p, $repo_id) = ($new_url, '', $ref_id);
                if ($u =~ s#^\Q$url\E(/|$)##) {
                        $p = $u;
                        $u = $url;
                        $repo_id = $self->{repo_id};
                }
                while (1) {
                        # It is possible to tag two different subdirectories at
                        # the same revision.  If the url for an existing ref
                        # does not match, we must either find a ref with a
                        # matching url or create a new ref by growing a tail.
                        $gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
                        my (undef, $max_commit) = $gs->rev_map_max(1);
                        last if (!$max_commit);
                        my ($url) = ::cmt_metadata($max_commit);
                        last if ($url eq $gs->metadata_url);
                        $ref_id .= '-';
                }
                print STDERR "Initializing parent: $ref_id\n" unless $::_q > 1;
        }
        $gs
}

sub call_authors_prog {
        my ($orig_author) = @_;
        $orig_author = command_oneline('rev-parse', '--sq-quote', $orig_author);
        my $author = `$::_authors_prog $orig_author`;
        if ($? != 0) {
                die "$::_authors_prog failed with exit code $?\n"
        }
        if ($author =~ /^\s*(.+?)\s*<(.*)>\s*$/) {
                my ($name, $email) = ($1, $2);
                $email = undef if length $2 == 0;
                return [$name, $email];
        } else {
                die "Author: $orig_author: $::_authors_prog returned "
                        . "invalid author format: $author\n";
        }
}

sub check_author {
        my ($author) = @_;
        if (!defined $author || length $author == 0) {
                $author = '(no author)';
        }
        if (!defined $::users{$author}) {
                if (defined $::_authors_prog) {
                        $::users{$author} = call_authors_prog($author);
                } elsif (defined $::_authors) {
                        die "Author: $author not defined in $::_authors file\n";
                }
        }
        $author;
}

sub find_extra_svk_parents {
        my ($self, $ed, $tickets, $parents) = @_;
        # aha!  svk:merge property changed...
        my @tickets = split "\n", $tickets;
        my @known_parents;
        for my $ticket ( @tickets ) {
                my ($uuid, $path, $rev) = split /:/, $ticket;
                if ( $uuid eq $self->ra_uuid ) {
                        my $url = $self->{url};
                        my $repos_root = $url;
                        my $branch_from = $path;
                        $branch_from =~ s{^/}{};
                        my $gs = $self->other_gs($repos_root."/".$branch_from,
                                                 $url,
                                                 $branch_from,
                                                 $rev,
                                                 $self->{ref_id});
                        if ( my $commit = $gs->rev_map_get($rev, $uuid) ) {
                                # wahey!  we found it, but it might be
                                # an old one (!)
                                push @known_parents, [ $rev, $commit ];
                        }
                }
        }
        # Ordering matters; highest-numbered commit merge tickets
        # first, as they may account for later merge ticket additions
        # or changes.
        @known_parents = map {$_->[1]} sort {$b->[0] <=> $a->[0]} @known_parents;
        for my $parent ( @known_parents ) {
                my @cmd = ('rev-list', $parent, map { "^$_" } @$parents );
                my ($msg_fh, $ctx) = command_output_pipe(@cmd);
                my $new;
                while ( <$msg_fh> ) {
                        $new=1;last;
                }
                command_close_pipe($msg_fh, $ctx);
                if ( $new ) {
                        print STDERR
                            "Found merge parent (svk:merge ticket): $parent\n";
                        push @$parents, $parent;
                }
        }
}

sub lookup_svn_merge {
        my $uuid = shift;
        my $url = shift;
        my $merge = shift;

        my ($source, $revs) = split ":", $merge;
        my $path = $source;
        $path =~ s{^/}{};
        my $gs = Git::SVN->find_by_url($url.$source, $url, $path);
        if ( !$gs ) {
                warn "Couldn't find revmap for $url$source\n";
                return;
        }
        my @ranges = split ",", $revs;
        my ($tip, $tip_commit);
        my @merged_commit_ranges;
        # find the tip
        for my $range ( @ranges ) {
                my ($bottom, $top) = split "-", $range;
                $top ||= $bottom;
                my $bottom_commit = $gs->find_rev_after( $bottom, 1, $top );
                my $top_commit = $gs->find_rev_before( $top, 1, $bottom );

                unless ($top_commit and $bottom_commit) {
                        warn "W:unknown path/rev in svn:mergeinfo "
                                ."dirprop: $source:$range\n";
                        next;
                }

                if (scalar(command('rev-parse', "$bottom_commit^@"))) {
                        push @merged_commit_ranges,
                             "$bottom_commit^..$top_commit";
                } else {
                        push @merged_commit_ranges, "$top_commit";
                }

                if ( !defined $tip or $top > $tip ) {
                        $tip = $top;
                        $tip_commit = $top_commit;
                }
        }
        return ($tip_commit, @merged_commit_ranges);
}

sub _rev_list {
        my ($msg_fh, $ctx) = command_output_pipe(
                "rev-list", @_,
               );
        my @rv;
        while ( <$msg_fh> ) {
                chomp;
                push @rv, $_;
        }
        command_close_pipe($msg_fh, $ctx);
        @rv;
}

sub check_cherry_pick {
        my $base = shift;
        my $tip = shift;
        my $parents = shift;
        my @ranges = @_;
        my %commits = map { $_ => 1 }
                _rev_list("--no-merges", $tip, "--not", $base, @$parents, "--");
        for my $range ( @ranges ) {
                delete @commits{_rev_list($range, "--")};
        }
        for my $commit (keys %commits) {
                if (has_no_changes($commit)) {
                        delete $commits{$commit};
                }
        }
        return (keys %commits);
}

sub has_no_changes {
        my $commit = shift;

        my @revs = split / /, command_oneline(
                qw(rev-list --parents -1 -m), $commit);

        # Commits with no parents, e.g. the start of a partial branch,
        # have changes by definition.
        return 1 if (@revs < 2);

        # Commits with multiple parents, e.g a merge, have no changes
        # by definition.
        return 0 if (@revs > 2);

        return (command_oneline("rev-parse", "$commit^{tree}") eq
                command_oneline("rev-parse", "$commit~1^{tree}"));
}

sub tie_for_persistent_memoization {
        my $hash = shift;
        my $path = shift;

        if ($can_use_yaml) {
                tie %$hash => 'Git::SVN::Memoize::YAML', "$path.yaml";
        } else {
                tie %$hash => 'Memoize::Storable', "$path.db", 'nstore';
        }
}

# The GIT_DIR environment variable is not always set until after the command
# line arguments are processed, so we can't memoize in a BEGIN block.
{
        my $memoized = 0;

        sub memoize_svn_mergeinfo_functions {
                return if $memoized;
                $memoized = 1;

                my $cache_path = "$ENV{GIT_DIR}/svn/.caches/";
                mkpath([$cache_path]) unless -d $cache_path;

                my %lookup_svn_merge_cache;
                my %check_cherry_pick_cache;
                my %has_no_changes_cache;

                tie_for_persistent_memoization(\%lookup_svn_merge_cache,
                    "$cache_path/lookup_svn_merge");
                memoize 'lookup_svn_merge',
                        SCALAR_CACHE => 'FAULT',
                        LIST_CACHE => ['HASH' => \%lookup_svn_merge_cache],
                ;

                tie_for_persistent_memoization(\%check_cherry_pick_cache,
                    "$cache_path/check_cherry_pick");
                memoize 'check_cherry_pick',
                        SCALAR_CACHE => 'FAULT',
                        LIST_CACHE => ['HASH' => \%check_cherry_pick_cache],
                ;

                tie_for_persistent_memoization(\%has_no_changes_cache,
                    "$cache_path/has_no_changes");
                memoize 'has_no_changes',
                        SCALAR_CACHE => ['HASH' => \%has_no_changes_cache],
                        LIST_CACHE => 'FAULT',
                ;
        }

        sub unmemoize_svn_mergeinfo_functions {
                return if not $memoized;
                $memoized = 0;

                Memoize::unmemoize 'lookup_svn_merge';
                Memoize::unmemoize 'check_cherry_pick';
                Memoize::unmemoize 'has_no_changes';
        }

        Memoize::memoize 'Git::SVN::repos_root';
}

END {
        # Force cache writeout explicitly instead of waiting for
        # global destruction to avoid segfault in Storable:
        # http://rt.cpan.org/Public/Bug/Display.html?id=36087
        unmemoize_svn_mergeinfo_functions();
}

sub parents_exclude {
        my $parents = shift;
        my @commits = @_;
        return unless @commits;

        my @excluded;
        my $excluded;
        do {
                my @cmd = ('rev-list', "-1", @commits, "--not", @$parents );
                $excluded = command_oneline(@cmd);
                if ( $excluded ) {
                        my @new;
                        my $found;
                        for my $commit ( @commits ) {
                                if ( $commit eq $excluded ) {
                                        push @excluded, $commit;
                                        $found++;
                                        last;
                                }
                                else {
                                        push @new, $commit;
                                }
                        }
                        die "saw commit '$excluded' in rev-list output, "
                                ."but we didn't ask for that commit (wanted: @commits --not @$parents)"
                                        unless $found;
                        @commits = @new;
                }
        }
                while ($excluded and @commits);

        return @excluded;
}


# note: this function should only be called if the various dirprops
# have actually changed
sub find_extra_svn_parents {
        my ($self, $ed, $mergeinfo, $parents) = @_;
        # aha!  svk:merge property changed...

        memoize_svn_mergeinfo_functions();

        # We first search for merged tips which are not in our
        # history.  Then, we figure out which git revisions are in
        # that tip, but not this revision.  If all of those revisions
        # are now marked as merge, we can add the tip as a parent.
        my @merges = split "\n", $mergeinfo;
        my @merge_tips;
        my $url = $self->{url};
        my $uuid = $self->ra_uuid;
        my %ranges;
        for my $merge ( @merges ) {
                my ($tip_commit, @ranges) =
                        lookup_svn_merge( $uuid, $url, $merge );
                unless (!$tip_commit or
                                grep { $_ eq $tip_commit } @$parents ) {
                        push @merge_tips, $tip_commit;
                        $ranges{$tip_commit} = \@ranges;
                } else {
                        push @merge_tips, undef;
                }
        }

        my %excluded = map { $_ => 1 }
                parents_exclude($parents, grep { defined } @merge_tips);

        # check merge tips for new parents
        my @new_parents;
        for my $merge_tip ( @merge_tips ) {
                my $spec = shift @merges;
                next unless $merge_tip and $excluded{$merge_tip};

                my $ranges = $ranges{$merge_tip};

                # check out 'new' tips
                my $merge_base;
                eval {
                        $merge_base = command_oneline(
                                "merge-base",
                                @$parents, $merge_tip,
                        );
                };
                if ($@) {
                        die "An error occurred during merge-base"
                                unless $@->isa("Git::Error::Command");

                        warn "W: Cannot find common ancestor between ".
                             "@$parents and $merge_tip. Ignoring merge info.\n";
                        next;
                }

                # double check that there are no missing non-merge commits
                my (@incomplete) = check_cherry_pick(
                        $merge_base, $merge_tip,
                        $parents,
                        @$ranges,
                       );

                if ( @incomplete ) {
                        warn "W:svn cherry-pick ignored ($spec) - missing "
                                .@incomplete." commit(s) (eg $incomplete[0])\n";
                } else {
                        warn
                                "Found merge parent (svn:mergeinfo prop): ",
                                        $merge_tip, "\n";
                        push @new_parents, $merge_tip;
                }
        }

        # cater for merges which merge commits from multiple branches
        if ( @new_parents > 1 ) {
                for ( my $i = 0; $i <= $#new_parents; $i++ ) {
                        for ( my $j = 0; $j <= $#new_parents; $j++ ) {
                                next if $i == $j;
                                next unless $new_parents[$i];
                                next unless $new_parents[$j];
                                my $revs = command_oneline(
                                        "rev-list", "-1",
                                        "$new_parents[$i]..$new_parents[$j]",
                                       );
                                if ( !$revs ) {
                                        undef($new_parents[$j]);
                                }
                        }
                }
        }
        push @$parents, grep { defined } @new_parents;
}

sub make_log_entry {
        my ($self, $rev, $parents, $ed) = @_;
        my $untracked = $self->get_untracked($ed);

        my @parents = @$parents;
        my $ps = $ed->{path_strip} || "";
        for my $path ( grep { m/$ps/ } %{$ed->{dir_prop}} ) {
                my $props = $ed->{dir_prop}{$path};
                if ( $props->{"svk:merge"} ) {
                        $self->find_extra_svk_parents
                                ($ed, $props->{"svk:merge"}, \@parents);
                }
                if ( $props->{"svn:mergeinfo"} ) {
                        $self->find_extra_svn_parents
                                ($ed,
                                 $props->{"svn:mergeinfo"},
                                 \@parents);
                }
        }

        open my $un, '>>', "$self->{dir}/unhandled.log" or croak $!;
        print $un "r$rev\n" or croak $!;
        print $un $_, "\n" foreach @$untracked;
        my %log_entry = ( parents => \@parents, revision => $rev,
                          log => '');

        my $headrev;
        my $logged = delete $self->{logged_rev_props};
        if (!$logged || $self->{-want_revprops}) {
                my $rp = $self->ra->rev_proplist($rev);
                foreach (sort keys %$rp) {
                        my $v = $rp->{$_};
                        if (/^svn:(author|date|log)$/) {
                                $log_entry{$1} = $v;
                        } elsif ($_ eq 'svm:headrev') {
                                $headrev = $v;
                        } else {
                                print $un "  rev_prop: ", uri_encode($_), ' ',
                                          uri_encode($v), "\n";
                        }
                }
        } else {
                map { $log_entry{$_} = $logged->{$_} } keys %$logged;
        }
        close $un or croak $!;

        $log_entry{date} = parse_svn_date($log_entry{date});
        $log_entry{log} .= "\n";
        my $author = $log_entry{author} = check_author($log_entry{author});
        my ($name, $email) = defined $::users{$author} ? @{$::users{$author}}
                                                       : ($author, undef);

        my ($commit_name, $commit_email) = ($name, $email);
        if ($_use_log_author) {
                my $name_field;
                if ($log_entry{log} =~ /From:\s+(.*\S)\s*\n/i) {
                        $name_field = $1;
                } elsif ($log_entry{log} =~ /Signed-off-by:\s+(.*\S)\s*\n/i) {
                        $name_field = $1;
                }
                if (!defined $name_field) {
                        if (!defined $email) {
                                $email = $name;
                        }
                } elsif ($name_field =~ /(.*?)\s+<(.*)>/) {
                        ($name, $email) = ($1, $2);
                } elsif ($name_field =~ /(.*)@/) {
                        ($name, $email) = ($1, $name_field);
                } else {
                        ($name, $email) = ($name_field, $name_field);
                }
        }
        if (defined $headrev && $self->use_svm_props) {
                if ($self->rewrite_root) {
                        die "Can't have both 'useSvmProps' and 'rewriteRoot' ",
                            "options set!\n";
                }
                if ($self->rewrite_uuid) {
                        die "Can't have both 'useSvmProps' and 'rewriteUUID' ",
                            "options set!\n";
                }
                my ($uuid, $r) = $headrev =~ m{^([a-f\d\-]{30,}):(\d+)$}i;
                # we don't want "SVM: initializing mirror for junk" ...
                return undef if $r == 0;
                my $svm = $self->svm;
                if ($uuid ne $svm->{uuid}) {
                        die "UUID mismatch on SVM path:\n",
                            "expected: $svm->{uuid}\n",
                            "     got: $uuid\n";
                }
                my $full_url = $self->full_url;
                $full_url =~ s#^\Q$svm->{replace}\E(/|$)#$svm->{source}$1# or
                             die "Failed to replace '$svm->{replace}' with ",
                                 "'$svm->{source}' in $full_url\n";
                # throw away username for storing in records
                remove_username($full_url);
                $log_entry{metadata} = "$full_url\@$r $uuid";
                $log_entry{svm_revision} = $r;
                $email ||= "$author\@$uuid";
                $commit_email ||= "$author\@$uuid";
        } elsif ($self->use_svnsync_props) {
                my $full_url = $self->svnsync->{url};
                $full_url .= "/$self->{path}" if length $self->{path};
                remove_username($full_url);
                my $uuid = $self->svnsync->{uuid};
                $log_entry{metadata} = "$full_url\@$rev $uuid";
                $email ||= "$author\@$uuid";
                $commit_email ||= "$author\@$uuid";
        } else {
                my $url = $self->metadata_url;
                remove_username($url);
                my $uuid = $self->rewrite_uuid || $self->ra->get_uuid;
                $log_entry{metadata} = "$url\@$rev " . $uuid;
                $email ||= "$author\@" . $uuid;
                $commit_email ||= "$author\@" . $uuid;
        }
        $log_entry{name} = $name;
        $log_entry{email} = $email;
        $log_entry{commit_name} = $commit_name;
        $log_entry{commit_email} = $commit_email;
        \%log_entry;
}

sub fetch {
        my ($self, $min_rev, $max_rev, @parents) = @_;
        my ($last_rev, $last_commit) = $self->last_rev_commit;
        my ($base, $head) = $self->get_fetch_range($min_rev, $max_rev);
        $self->ra->gs_fetch_loop_common($base, $head, [$self]);
}

sub set_tree_cb {
        my ($self, $log_entry, $tree, $rev, $date, $author) = @_;
        $self->{inject_parents} = { $rev => $tree };
        $self->fetch(undef, undef);
}

sub set_tree {
        my ($self, $tree) = (shift, shift);
        my $log_entry = ::get_commit_entry($tree);
        unless ($self->{last_rev}) {
                fatal("Must have an existing revision to commit");
        }
        my %ed_opts = ( r => $self->{last_rev},
                        log => $log_entry->{log},
                        ra => $self->ra,
                        tree_a => $self->{last_commit},
                        tree_b => $tree,
                        editor_cb => sub {
                               $self->set_tree_cb($log_entry, $tree, @_) },
                        svn_path => $self->{path} );
        if (!Git::SVN::Editor->new(\%ed_opts)->apply_diff) {
                print "No changes\nr$self->{last_rev} = $tree\n";
        }
}

sub rebuild_from_rev_db {
        my ($self, $path) = @_;
        my $r = -1;
        open my $fh, '<', $path or croak "open: $!";
        binmode $fh or croak "binmode: $!";
        while (<$fh>) {
                length($_) == 41 or croak "inconsistent size in ($_) != 41";
                chomp($_);
                ++$r;
                next if $_ eq ('0' x 40);
                $self->rev_map_set($r, $_);
                print "r$r = $_\n";
        }
        close $fh or croak "close: $!";
        unlink $path or croak "unlink: $!";
}

sub rebuild {
        my ($self) = @_;
        my $map_path = $self->map_path;
        my $partial = (-e $map_path && ! -z $map_path);
        return unless ::verify_ref($self->refname.'^0');
        if (!$partial && ($self->use_svm_props || $self->no_metadata)) {
                my $rev_db = $self->rev_db_path;
                $self->rebuild_from_rev_db($rev_db);
                if ($self->use_svm_props) {
                        my $svm_rev_db = $self->rev_db_path($self->svm_uuid);
                        $self->rebuild_from_rev_db($svm_rev_db);
                }
                $self->unlink_rev_db_symlink;
                return;
        }
        print "Rebuilding $map_path ...\n" if (!$partial);
        my ($base_rev, $head) = ($partial ? $self->rev_map_max_norebuild(1) :
                (undef, undef));
        my ($log, $ctx) =
            command_output_pipe(qw/rev-list --pretty=raw --reverse/,
                                ($head ? "$head.." : "") . $self->refname,
                                '--');
        my $metadata_url = $self->metadata_url;
        remove_username($metadata_url);
        my $svn_uuid = $self->rewrite_uuid || $self->ra_uuid;
        my $c;
        while (<$log>) {
                if ( m{^commit ($::sha1)$} ) {
                        $c = $1;
                        next;
                }
                next unless s{^\s*(git-svn-id:)}{$1};
                my ($url, $rev, $uuid) = ::extract_metadata($_);
                remove_username($url);

                # ignore merges (from set-tree)
                next if (!defined $rev || !$uuid);

                # if we merged or otherwise started elsewhere, this is
                # how we break out of it
                if (($uuid ne $svn_uuid) ||
                    ($metadata_url && $url && ($url ne $metadata_url))) {
                        next;
                }
                if ($partial && $head) {
                        print "Partial-rebuilding $map_path ...\n";
                        print "Currently at $base_rev = $head\n";
                        $head = undef;
                }

                $self->rev_map_set($rev, $c);
                print "r$rev = $c\n";
        }
        command_close_pipe($log, $ctx);
        print "Done rebuilding $map_path\n" if (!$partial || !$head);
        my $rev_db_path = $self->rev_db_path;
        if (-f $self->rev_db_path) {
                unlink $self->rev_db_path or croak "unlink: $!";
        }
        $self->unlink_rev_db_symlink;
}

# rev_map:
# Tie::File seems to be prone to offset errors if revisions get sparse,
# it's not that fast, either.  Tie::File is also not in Perl 5.6.  So
# one of my favorite modules is out :<  Next up would be one of the DBM
# modules, but I'm not sure which is most portable...
#
# This is the replacement for the rev_db format, which was too big
# and inefficient for large repositories with a lot of sparse history
# (mainly tags)
#
# The format is this:
#   - 24 bytes for every record,
#     * 4 bytes for the integer representing an SVN revision number
#     * 20 bytes representing the sha1 of a git commit
#   - No empty padding records like the old format
#     (except the last record, which can be overwritten)
#   - new records are written append-only since SVN revision numbers
#     increase monotonically
#   - lookups on SVN revision number are done via a binary search
#   - Piping the file to xxd -c24 is a good way of dumping it for
#     viewing or editing (piped back through xxd -r), should the need
#     ever arise.
#   - The last record can be padding revision with an all-zero sha1
#     This is used to optimize fetch performance when using multiple
#     "fetch" directives in .git/config
#
# These files are disposable unless noMetadata or useSvmProps is set

sub _rev_map_set {
        my ($fh, $rev, $commit) = @_;

        binmode $fh or croak "binmode: $!";
        my $size = (stat($fh))[7];
        ($size % 24) == 0 or croak "inconsistent size: $size";

        my $wr_offset = 0;
        if ($size > 0) {
                sysseek($fh, -24, SEEK_END) or croak "seek: $!";
                my $read = sysread($fh, my $buf, 24) or croak "read: $!";
                $read == 24 or croak "read only $read bytes (!= 24)";
                my ($last_rev, $last_commit) = unpack(rev_map_fmt, $buf);
                if ($last_commit eq ('0' x40)) {
                        if ($size >= 48) {
                                sysseek($fh, -48, SEEK_END) or croak "seek: $!";
                                $read = sysread($fh, $buf, 24) or
                                    croak "read: $!";
                                $read == 24 or
                                    croak "read only $read bytes (!= 24)";
                                ($last_rev, $last_commit) =
                                    unpack(rev_map_fmt, $buf);
                                if ($last_commit eq ('0' x40)) {
                                        croak "inconsistent .rev_map\n";
                                }
                        }
                        if ($last_rev >= $rev) {
                                croak "last_rev is higher!: $last_rev >= $rev";
                        }
                        $wr_offset = -24;
                }
        }
        sysseek($fh, $wr_offset, SEEK_END) or croak "seek: $!";
        syswrite($fh, pack(rev_map_fmt, $rev, $commit), 24) == 24 or
          croak "write: $!";
}

sub _rev_map_reset {
        my ($fh, $rev, $commit) = @_;
        my $c = _rev_map_get($fh, $rev);
        $c eq $commit or die "_rev_map_reset(@_) commit $c does not match!\n";
        my $offset = sysseek($fh, 0, SEEK_CUR) or croak "seek: $!";
        truncate $fh, $offset or croak "truncate: $!";
}

sub mkfile {
        my ($path) = @_;
        unless (-e $path) {
                my ($dir, $base) = ($path =~ m#^(.*?)/?([^/]+)$#);
                mkpath([$dir]) unless -d $dir;
                open my $fh, '>>', $path or die "Couldn't create $path: $!\n";
                close $fh or die "Couldn't close (create) $path: $!\n";
        }
}

sub rev_map_set {
        my ($self, $rev, $commit, $update_ref, $uuid) = @_;
        defined $commit or die "missing arg3\n";
        length $commit == 40 or die "arg3 must be a full SHA1 hexsum\n";
        my $db = $self->map_path($uuid);
        my $db_lock = "$db.lock";
        my $sigmask;
        $update_ref ||= 0;
        if ($update_ref) {
                $sigmask = POSIX::SigSet->new();
                my $signew = POSIX::SigSet->new(SIGINT, SIGHUP, SIGTERM,
                        SIGALRM, SIGUSR1, SIGUSR2);
                sigprocmask(SIG_BLOCK, $signew, $sigmask) or
                        croak "Can't block signals: $!";
        }
        mkfile($db);

        $LOCKFILES{$db_lock} = 1;
        my $sync;
        # both of these options make our .rev_db file very, very important
        # and we can't afford to lose it because rebuild() won't work
        if ($self->use_svm_props || $self->no_metadata) {
                $sync = 1;
                copy($db, $db_lock) or die "rev_map_set(@_): ",
                                           "Failed to copy: ",
                                           "$db => $db_lock ($!)\n";
        } else {
                rename $db, $db_lock or die "rev_map_set(@_): ",
                                            "Failed to rename: ",
                                            "$db => $db_lock ($!)\n";
        }

        sysopen(my $fh, $db_lock, O_RDWR | O_CREAT)
             or croak "Couldn't open $db_lock: $!\n";
        $update_ref eq 'reset' ? _rev_map_reset($fh, $rev, $commit) :
                                 _rev_map_set($fh, $rev, $commit);
        if ($sync) {
                $fh->flush or die "Couldn't flush $db_lock: $!\n";
                $fh->sync or die "Couldn't sync $db_lock: $!\n";
        }
        close $fh or croak $!;
        if ($update_ref) {
                $_head = $self;
                my $note = "";
                $note = " ($update_ref)" if ($update_ref !~ /^\d*$/);
                command_noisy('update-ref', '-m', "r$rev$note",
                              $self->refname, $commit);
        }
        rename $db_lock, $db or die "rev_map_set(@_): ", "Failed to rename: ",
                                    "$db_lock => $db ($!)\n";
        delete $LOCKFILES{$db_lock};
        if ($update_ref) {
                sigprocmask(SIG_SETMASK, $sigmask) or
                        croak "Can't restore signal mask: $!";
        }
}

# If want_commit, this will return an array of (rev, commit) where
# commit _must_ be a valid commit in the archive.
# Otherwise, it'll return the max revision (whether or not the
# commit is valid or just a 0x40 placeholder).
sub rev_map_max {
        my ($self, $want_commit) = @_;
        $self->rebuild;
        my ($r, $c) = $self->rev_map_max_norebuild($want_commit);
        $want_commit ? ($r, $c) : $r;
}

sub rev_map_max_norebuild {
        my ($self, $want_commit) = @_;
        my $map_path = $self->map_path;
        stat $map_path or return $want_commit ? (0, undef) : 0;
        sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
        binmode $fh or croak "binmode: $!";
        my $size = (stat($fh))[7];
        ($size % 24) == 0 or croak "inconsistent size: $size";

        if ($size == 0) {
                close $fh or croak "close: $!";
                return $want_commit ? (0, undef) : 0;
        }

        sysseek($fh, -24, SEEK_END) or croak "seek: $!";
        sysread($fh, my $buf, 24) == 24 or croak "read: $!";
        my ($r, $c) = unpack(rev_map_fmt, $buf);
        if ($want_commit && $c eq ('0' x40)) {
                if ($size < 48) {
                        return $want_commit ? (0, undef) : 0;
                }
                sysseek($fh, -48, SEEK_END) or croak "seek: $!";
                sysread($fh, $buf, 24) == 24 or croak "read: $!";
                ($r, $c) = unpack(rev_map_fmt, $buf);
                if ($c eq ('0'x40)) {
                        croak "Penultimate record is all-zeroes in $map_path";
                }
        }
        close $fh or croak "close: $!";
        $want_commit ? ($r, $c) : $r;
}

sub rev_map_get {
        my ($self, $rev, $uuid) = @_;
        my $map_path = $self->map_path($uuid);
        return undef unless -e $map_path;

        sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
        my $c = _rev_map_get($fh, $rev);
        close($fh) or croak "close: $!";
        $c
}

sub _rev_map_get {
        my ($fh, $rev) = @_;

        binmode $fh or croak "binmode: $!";
        my $size = (stat($fh))[7];
        ($size % 24) == 0 or croak "inconsistent size: $size";

        if ($size == 0) {
                return undef;
        }

        my ($l, $u) = (0, $size - 24);
        my ($r, $c, $buf);

        while ($l <= $u) {
                my $i = int(($l/24 + $u/24) / 2) * 24;
                sysseek($fh, $i, SEEK_SET) or croak "seek: $!";
                sysread($fh, my $buf, 24) == 24 or croak "read: $!";
                my ($r, $c) = unpack(rev_map_fmt, $buf);

                if ($r < $rev) {
                        $l = $i + 24;
                } elsif ($r > $rev) {
                        $u = $i - 24;
                } else { # $r == $rev
                        return $c eq ('0' x 40) ? undef : $c;
                }
        }
        undef;
}

# Finds the first svn revision that exists on (if $eq_ok is true) or
# before $rev for the current branch.  It will not search any lower
# than $min_rev.  Returns the git commit hash and svn revision number
# if found, else (undef, undef).
sub find_rev_before {
        my ($self, $rev, $eq_ok, $min_rev) = @_;
        --$rev unless $eq_ok;
        $min_rev ||= 1;
        my $max_rev = $self->rev_map_max;
        $rev = $max_rev if ($rev > $max_rev);
        while ($rev >= $min_rev) {
                if (my $c = $self->rev_map_get($rev)) {
                        return ($rev, $c);
                }
                --$rev;
        }
        return (undef, undef);
}

# Finds the first svn revision that exists on (if $eq_ok is true) or
# after $rev for the current branch.  It will not search any higher
# than $max_rev.  Returns the git commit hash and svn revision number
# if found, else (undef, undef).
sub find_rev_after {
        my ($self, $rev, $eq_ok, $max_rev) = @_;
        ++$rev unless $eq_ok;
        $max_rev ||= $self->rev_map_max;
        while ($rev <= $max_rev) {
                if (my $c = $self->rev_map_get($rev)) {
                        return ($rev, $c);
                }
                ++$rev;
        }
        return (undef, undef);
}

sub _new {
        my ($class, $repo_id, $ref_id, $path) = @_;
        unless (defined $repo_id && length $repo_id) {
                $repo_id = $Git::SVN::default_repo_id;
        }
        unless (defined $ref_id && length $ref_id) {
                $_prefix = '' unless defined($_prefix);
                $_[2] = $ref_id =
                             "refs/remotes/$_prefix$Git::SVN::default_ref_id";
        }
        $_[1] = $repo_id;
        my $dir = "$ENV{GIT_DIR}/svn/$ref_id";

        # Older repos imported by us used $GIT_DIR/svn/foo instead of
        # $GIT_DIR/svn/refs/remotes/foo when tracking refs/remotes/foo
        if ($ref_id =~ m{^refs/remotes/(.*)}) {
                my $old_dir = "$ENV{GIT_DIR}/svn/$1";
                if (-d $old_dir && ! -d $dir) {
                        $dir = $old_dir;
                }
        }

        $_[3] = $path = '' unless (defined $path);
        mkpath([$dir]);
        bless {
                ref_id => $ref_id, dir => $dir, index => "$dir/index",
                path => $path, config => "$ENV{GIT_DIR}/svn/config",
                map_root => "$dir/.rev_map", repo_id => $repo_id }, $class;
}

# for read-only access of old .rev_db formats
sub unlink_rev_db_symlink {
        my ($self) = @_;
        my $link = $self->rev_db_path;
        $link =~ s/\.[\w-]+$// or croak "missing UUID at the end of $link";
        if (-l $link) {
                unlink $link or croak "unlink: $link failed!";
        }
}

sub rev_db_path {
        my ($self, $uuid) = @_;
        my $db_path = $self->map_path($uuid);
        $db_path =~ s{/\.rev_map\.}{/\.rev_db\.}
            or croak "map_path: $db_path does not contain '/.rev_map.' !";
        $db_path;
}

# the new replacement for .rev_db
sub map_path {
        my ($self, $uuid) = @_;
        $uuid ||= $self->ra_uuid;
        "$self->{map_root}.$uuid";
}

sub uri_encode {
        my ($f) = @_;
        $f =~ s#([^a-zA-Z0-9\*!\:_\./\-])#uc sprintf("%%%02x",ord($1))#eg;
        $f
}

sub uri_decode {
        my ($f) = @_;
        $f =~ s#%([0-9a-fA-F]{2})#chr(hex($1))#eg;
        $f
}

sub remove_username {
        $_[0] =~ s{^([^:]*://)[^@]+@}{$1};
}

package Git::SVN::Log;
use strict;
use warnings;
use Git::SVN::Utils qw(fatal);
use POSIX qw/strftime/;
use constant commit_log_separator => ('-' x 72) . "\n";
use vars qw/$TZ $limit $color $pager $non_recursive $verbose $oneline
            %rusers $show_commit $incremental/;
my $l_fmt;

sub cmt_showable {
        my ($c) = @_;
        return 1 if defined $c->{r};

        # big commit message got truncated by the 16k pretty buffer in rev-list
        if ($c->{l} && $c->{l}->[-1] eq "...\n" &&
                                $c->{a_raw} =~ /\@([a-f\d\-]+)>$/) {
                @{$c->{l}} = ();
                my @log = command(qw/cat-file commit/, $c->{c});

                # shift off the headers
                shift @log while ($log[0] ne '');
                shift @log;

                # TODO: make $c->{l} not have a trailing newline in the future
                @{$c->{l}} = map { "$_\n" } grep !/^git-svn-id: /, @log;

                (undef, $c->{r}, undef) = ::extract_metadata(
                                (grep(/^git-svn-id: /, @log))[-1]);
        }
        return defined $c->{r};
}

sub log_use_color {
        return $color || Git->repository->get_colorbool('color.diff');
}

sub git_svn_log_cmd {
        my ($r_min, $r_max, @args) = @_;
        my $head = 'HEAD';
        my (@files, @log_opts);
        foreach my $x (@args) {
                if ($x eq '--' || @files) {
                        push @files, $x;
                } else {
                        if (::verify_ref("$x^0")) {
                                $head = $x;
                        } else {
                                push @log_opts, $x;
                        }
                }
        }

        my ($url, $rev, $uuid, $gs) = ::working_head_info($head);
        $gs ||= Git::SVN->_new;
        my @cmd = (qw/log --abbrev-commit --pretty=raw --default/,
                   $gs->refname);
        push @cmd, '-r' unless $non_recursive;
        push @cmd, qw/--raw --name-status/ if $verbose;
        push @cmd, '--color' if log_use_color();
        push @cmd, @log_opts;
        if (defined $r_max && $r_max == $r_min) {
                push @cmd, '--max-count=1';
                if (my $c = $gs->rev_map_get($r_max)) {
                        push @cmd, $c;
                }
        } elsif (defined $r_max) {
                if ($r_max < $r_min) {
                        ($r_min, $r_max) = ($r_max, $r_min);
                }
                my (undef, $c_max) = $gs->find_rev_before($r_max, 1, $r_min);
                my (undef, $c_min) = $gs->find_rev_after($r_min, 1, $r_max);
                # If there are no commits in the range, both $c_max and $c_min
                # will be undefined.  If there is at least 1 commit in the
                # range, both will be defined.
                return () if !defined $c_min || !defined $c_max;
                if ($c_min eq $c_max) {
                        push @cmd, '--max-count=1', $c_min;
                } else {
                        push @cmd, '--boundary', "$c_min..$c_max";
                }
        }
        return (@cmd, @files);
}

# adapted from pager.c
sub config_pager {
        if (! -t *STDOUT) {
                $ENV{GIT_PAGER_IN_USE} = 'false';
                $pager = undef;
                return;
        }
        chomp($pager = command_oneline(qw(var GIT_PAGER)));
        if ($pager eq 'cat') {
                $pager = undef;
        }
        $ENV{GIT_PAGER_IN_USE} = defined($pager);
}

sub run_pager {
        return unless defined $pager;
        pipe my ($rfd, $wfd) or return;
        defined(my $pid = fork) or fatal "Can't fork: $!";
        if (!$pid) {
                open STDOUT, '>&', $wfd or
                                     fatal "Can't redirect to stdout: $!";
                return;
        }
        open STDIN, '<&', $rfd or fatal "Can't redirect stdin: $!";
        $ENV{LESS} ||= 'FRSX';
        exec $pager or fatal "Can't run pager: $! ($pager)";
}

sub format_svn_date {
        my $t = shift || time;
        my $gmoff = Git::SVN::get_tz($t);
        return strftime("%Y-%m-%d %H:%M:%S $gmoff (%a, %d %b %Y)", localtime($t));
}

sub parse_git_date {
        my ($t, $tz) = @_;
        # Date::Parse isn't in the standard Perl distro :(
        if ($tz =~ s/^\+//) {
                $t += tz_to_s_offset($tz);
        } elsif ($tz =~ s/^\-//) {
                $t -= tz_to_s_offset($tz);
        }
        return $t;
}

sub set_local_timezone {
        if (defined $TZ) {
                $ENV{TZ} = $TZ;
        } else {
                delete $ENV{TZ};
        }
}

sub tz_to_s_offset {
        my ($tz) = @_;
        $tz =~ s/(\d\d)$//;
        return ($1 * 60) + ($tz * 3600);
}

sub get_author_info {
        my ($dest, $author, $t, $tz) = @_;
        $author =~ s/(?:^\s*|\s*$)//g;
        $dest->{a_raw} = $author;
        my $au;
        if ($::_authors) {
                $au = $rusers{$author} || undef;
        }
        if (!$au) {
                ($au) = ($author =~ /<([^>]+)\@[^>]+>$/);
        }
        $dest->{t} = $t;
        $dest->{tz} = $tz;
        $dest->{a} = $au;
        $dest->{t_utc} = parse_git_date($t, $tz);
}

sub process_commit {
        my ($c, $r_min, $r_max, $defer) = @_;
        if (defined $r_min && defined $r_max) {
                if ($r_min == $c->{r} && $r_min == $r_max) {
                        show_commit($c);
                        return 0;
                }
                return 1 if $r_min == $r_max;
                if ($r_min < $r_max) {
                        # we need to reverse the print order
                        return 0 if (defined $limit && --$limit < 0);
                        push @$defer, $c;
                        return 1;
                }
                if ($r_min != $r_max) {
                        return 1 if ($r_min < $c->{r});
                        return 1 if ($r_max > $c->{r});
                }
        }
        return 0 if (defined $limit && --$limit < 0);
        show_commit($c);
        return 1;
}

sub show_commit {
        my $c = shift;
        if ($oneline) {
                my $x = "\n";
                if (my $l = $c->{l}) {
                        while ($l->[0] =~ /^\s*$/) { shift @$l }
                        $x = $l->[0];
                }
                $l_fmt ||= 'A' . length($c->{r});
                print 'r',pack($l_fmt, $c->{r}),' | ';
                print "$c->{c} | " if $show_commit;
                print $x;
        } else {
                show_commit_normal($c);
        }
}

sub show_commit_changed_paths {
        my ($c) = @_;
        return unless $c->{changed};
        print "Changed paths:\n", @{$c->{changed}};
}

sub show_commit_normal {
        my ($c) = @_;
        print commit_log_separator, "r$c->{r} | ";
        print "$c->{c} | " if $show_commit;
        print "$c->{a} | ", format_svn_date($c->{t_utc}), ' | ';
        my $nr_line = 0;

        if (my $l = $c->{l}) {
                while ($l->[$#$l] eq "\n" && $#$l > 0
                                          && $l->[($#$l - 1)] eq "\n") {
                        pop @$l;
                }
                $nr_line = scalar @$l;
                if (!$nr_line) {
                        print "1 line\n\n\n";
                } else {
                        if ($nr_line == 1) {
                                $nr_line = '1 line';
                        } else {
                                $nr_line .= ' lines';
                        }
                        print $nr_line, "\n";
                        show_commit_changed_paths($c);
                        print "\n";
                        print $_ foreach @$l;
                }
        } else {
                print "1 line\n";
                show_commit_changed_paths($c);
                print "\n";

        }
        foreach my $x (qw/raw stat diff/) {
                if ($c->{$x}) {
                        print "\n";
                        print $_ foreach @{$c->{$x}}
                }
        }
}

sub cmd_show_log {
        my (@args) = @_;
        my ($r_min, $r_max);
        my $r_last = -1; # prevent dupes
        set_local_timezone();
        if (defined $::_revision) {
                if ($::_revision =~ /^(\d+):(\d+)$/) {
                        ($r_min, $r_max) = ($1, $2);
                } elsif ($::_revision =~ /^\d+$/) {
                        $r_min = $r_max = $::_revision;
                } else {
                        fatal "-r$::_revision is not supported, use ",
                                "standard 'git log' arguments instead";
                }
        }

        config_pager();
        @args = git_svn_log_cmd($r_min, $r_max, @args);
        if (!@args) {
                print commit_log_separator unless $incremental || $oneline;
                return;
        }
        my $log = command_output_pipe(@args);
        run_pager();
        my (@k, $c, $d, $stat);
        my $esc_color = qr/(?:\033\[(?:(?:\d+;)*\d*)?m)*/;
        while (<$log>) {
                if (/^${esc_color}commit (?:- )?($::sha1_short)/o) {
                        my $cmt = $1;
                        if ($c && cmt_showable($c) && $c->{r} != $r_last) {
                                $r_last = $c->{r};
                                process_commit($c, $r_min, $r_max, \@k) or
                                                                goto out;
                        }
                        $d = undef;
                        $c = { c => $cmt };
                } elsif (/^${esc_color}author (.+) (\d+) ([\-\+]?\d+)$/o) {
                        get_author_info($c, $1, $2, $3);
                } elsif (/^${esc_color}(?:tree|parent|committer) /o) {
                        # ignore
                } elsif (/^${esc_color}:\d{6} \d{6} $::sha1_short/o) {
                        push @{$c->{raw}}, $_;
                } elsif (/^${esc_color}[ACRMDT]\t/) {
                        # we could add $SVN->{svn_path} here, but that requires
                        # remote access at the moment (repo_path_split)...
                        s#^(${esc_color})([ACRMDT])\t#$1   $2 #o;
                        push @{$c->{changed}}, $_;
                } elsif (/^${esc_color}diff /o) {
                        $d = 1;
                        push @{$c->{diff}}, $_;
                } elsif ($d) {
                        push @{$c->{diff}}, $_;
                } elsif (/^\ .+\ \|\s*\d+\ $esc_color[\+\-]*
                          $esc_color*[\+\-]*$esc_color$/x) {
                        $stat = 1;
                        push @{$c->{stat}}, $_;
                } elsif ($stat && /^ \d+ files changed, \d+ insertions/) {
                        push @{$c->{stat}}, $_;
                        $stat = undef;
                } elsif (/^${esc_color}    (git-svn-id:.+)$/o) {
                        ($c->{url}, $c->{r}, undef) = ::extract_metadata($1);
                } elsif (s/^${esc_color}    //o) {
                        push @{$c->{l}}, $_;
                }
        }
        if ($c && defined $c->{r} && $c->{r} != $r_last) {
                $r_last = $c->{r};
                process_commit($c, $r_min, $r_max, \@k);
        }
        if (@k) {
                ($r_min, $r_max) = ($r_max, $r_min);
                process_commit($_, $r_min, $r_max) foreach reverse @k;
        }
out:
        close $log;
        print commit_log_separator unless $incremental || $oneline;
}

sub cmd_blame {
        my $path = pop;

        config_pager();
        run_pager();

        my ($fh, $ctx, $rev);

        if ($_git_format) {
                ($fh, $ctx) = command_output_pipe('blame', @_, $path);
                while (my $line = <$fh>) {
                        if ($line =~ /^\^?([[:xdigit:]]+)\s/) {
                                # Uncommitted edits show up as a rev ID of
                                # all zeros, which we can't look up with
                                # cmt_metadata
                                if ($1 !~ /^0+$/) {
                                        (undef, $rev, undef) =
                                                ::cmt_metadata($1);
                                        $rev = '0' if (!$rev);
                                } else {
                                        $rev = '0';
                                }
                                $rev = sprintf('%-10s', $rev);
                                $line =~ s/^\^?[[:xdigit:]]+(\s)/$rev$1/;
                        }
                        print $line;
                }
        } else {
                ($fh, $ctx) = command_output_pipe('blame', '-p', @_, 'HEAD',
                                                  '--', $path);
                my ($sha1);
                my %authors;
                my @buffer;
                my %dsha; #distinct sha keys

                while (my $line = <$fh>) {
                        push @buffer, $line;
                        if ($line =~ /^([[:xdigit:]]{40})\s\d+\s\d+/) {
                                $dsha{$1} = 1;
                        }
                }

                my $s2r = ::cmt_sha2rev_batch([keys %dsha]);

                foreach my $line (@buffer) {
                        if ($line =~ /^([[:xdigit:]]{40})\s\d+\s\d+/) {
                                $rev = $s2r->{$1};
                                $rev = '0' if (!$rev)
                        }
                        elsif ($line =~ /^author (.*)/) {
                                $authors{$rev} = $1;
                                $authors{$rev} =~ s/\s/_/g;
                        }
                        elsif ($line =~ /^\t(.*)$/) {
                                printf("%6s %10s %s\n", $rev, $authors{$rev}, $1);
                        }
                }
        }
        command_close_pipe($fh, $ctx);
}

package Git::SVN::Migration;
# these version numbers do NOT correspond to actual version numbers
# of git nor git-svn.  They are just relative.
#
# v0 layout: .git/$id/info/url, refs/heads/$id-HEAD
#
# v1 layout: .git/$id/info/url, refs/remotes/$id
#
# v2 layout: .git/svn/$id/info/url, refs/remotes/$id
#
# v3 layout: .git/svn/$id, refs/remotes/$id
#            - info/url may remain for backwards compatibility
#            - this is what we migrate up to this layout automatically,
#            - this will be used by git svn init on single branches
# v3.1 layout (auto migrated):
#            - .rev_db => .rev_db.$UUID, .rev_db will remain as a symlink
#              for backwards compatibility
#
# v4 layout: .git/svn/$repo_id/$id, refs/remotes/$repo_id/$id
#            - this is only created for newly multi-init-ed
#              repositories.  Similar in spirit to the
#              --use-separate-remotes option in git-clone (now default)
#            - we do not automatically migrate to this (following
#              the example set by core git)
#
# v5 layout: .rev_db.$UUID => .rev_map.$UUID
#            - newer, more-efficient format that uses 24-bytes per record
#              with no filler space.
#            - use xxd -c24 < .rev_map.$UUID to view and debug
#            - This is a one-way migration, repositories updated to the
#              new format will not be able to use old git-svn without
#              rebuilding the .rev_db.  Rebuilding the rev_db is not
#              possible if noMetadata or useSvmProps are set; but should
#              be no problem for users that use the (sensible) defaults.
use strict;
use warnings;
use Carp qw/croak/;
use File::Path qw/mkpath/;
use File::Basename qw/dirname basename/;
use vars qw/$_minimize/;

sub migrate_from_v0 {
        my $git_dir = $ENV{GIT_DIR};
        return undef unless -d $git_dir;
        my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
        my $migrated = 0;
        while (<$fh>) {
                chomp;
                my ($id, $orig_ref) = ($_, $_);
                next unless $id =~ s#^refs/heads/(.+)-HEAD$#$1#;
                next unless -f "$git_dir/$id/info/url";
                my $new_ref = "refs/remotes/$id";
                if (::verify_ref("$new_ref^0")) {
                        print STDERR "W: $orig_ref is probably an old ",
                                     "branch used by an ancient version of ",
                                     "git-svn.\n",
                                     "However, $new_ref also exists.\n",
                                     "We will not be able ",
                                     "to use this branch until this ",
                                     "ambiguity is resolved.\n";
                        next;
                }
                print STDERR "Migrating from v0 layout...\n" if !$migrated;
                print STDERR "Renaming ref: $orig_ref => $new_ref\n";
                command_noisy('update-ref', $new_ref, $orig_ref);
                command_noisy('update-ref', '-d', $orig_ref, $orig_ref);
                $migrated++;
        }
        command_close_pipe($fh, $ctx);
        print STDERR "Done migrating from v0 layout...\n" if $migrated;
        $migrated;
}

sub migrate_from_v1 {
        my $git_dir = $ENV{GIT_DIR};
        my $migrated = 0;
        return $migrated unless -d $git_dir;
        my $svn_dir = "$git_dir/svn";

        # just in case somebody used 'svn' as their $id at some point...
        return $migrated if -d $svn_dir && ! -f "$svn_dir/info/url";

        print STDERR "Migrating from a git-svn v1 layout...\n";
        mkpath([$svn_dir]);
        print STDERR "Data from a previous version of git-svn exists, but\n\t",
                     "$svn_dir\n\t(required for this version ",
                     "($::VERSION) of git-svn) does not exist.\n";
        my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
        while (<$fh>) {
                my $x = $_;
                next unless $x =~ s#^refs/remotes/##;
                chomp $x;
                next unless -f "$git_dir/$x/info/url";
                my $u = eval { ::file_to_s("$git_dir/$x/info/url") };
                next unless $u;
                my $dn = dirname("$git_dir/svn/$x");
                mkpath([$dn]) unless -d $dn;
                if ($x eq 'svn') { # they used 'svn' as GIT_SVN_ID:
                        mkpath(["$git_dir/svn/svn"]);
                        print STDERR " - $git_dir/$x/info => ",
                                        "$git_dir/svn/$x/info\n";
                        rename "$git_dir/$x/info", "$git_dir/svn/$x/info" or
                               croak "$!: $x";
                        # don't worry too much about these, they probably
                        # don't exist with repos this old (save for index,
                        # and we can easily regenerate that)
                        foreach my $f (qw/unhandled.log index .rev_db/) {
                                rename "$git_dir/$x/$f", "$git_dir/svn/$x/$f";
                        }
                } else {
                        print STDERR " - $git_dir/$x => $git_dir/svn/$x\n";
                        rename "$git_dir/$x", "$git_dir/svn/$x" or
                               croak "$!: $x";
                }
                $migrated++;
        }
        command_close_pipe($fh, $ctx);
        print STDERR "Done migrating from a git-svn v1 layout\n";
        $migrated;
}

sub read_old_urls {
        my ($l_map, $pfx, $path) = @_;
        my @dir;
        foreach (<$path/*>) {
                if (-r "$_/info/url") {
                        $pfx .= '/' if $pfx && $pfx !~ m!/$!;
                        my $ref_id = $pfx . basename $_;
                        my $url = ::file_to_s("$_/info/url");
                        $l_map->{$ref_id} = $url;
                } elsif (-d $_) {
                        push @dir, $_;
                }
        }
        foreach (@dir) {
                my $x = $_;
                $x =~ s!^\Q$ENV{GIT_DIR}\E/svn/!!o;
                read_old_urls($l_map, $x, $_);
        }
}

sub migrate_from_v2 {
        my @cfg = command(qw/config -l/);
        return if grep /^svn-remote\..+\.url=/, @cfg;
        my %l_map;
        read_old_urls(\%l_map, '', "$ENV{GIT_DIR}/svn");
        my $migrated = 0;

        foreach my $ref_id (sort keys %l_map) {
                eval { Git::SVN->init($l_map{$ref_id}, '', undef, $ref_id) };
                if ($@) {
                        Git::SVN->init($l_map{$ref_id}, '', $ref_id, $ref_id);
                }
                $migrated++;
        }
        $migrated;
}

sub minimize_connections {
        my $r = Git::SVN::read_all_remotes();
        my $new_urls = {};
        my $root_repos = {};
        foreach my $repo_id (keys %$r) {
                my $url = $r->{$repo_id}->{url} or next;
                my $fetch = $r->{$repo_id}->{fetch} or next;
                my $ra = Git::SVN::Ra->new($url);

                # skip existing cases where we already connect to the root
                if (($ra->{url} eq $ra->{repos_root}) ||
                    ($ra->{repos_root} eq $repo_id)) {
                        $root_repos->{$ra->{url}} = $repo_id;
                        next;
                }

                my $root_ra = Git::SVN::Ra->new($ra->{repos_root});
                my $root_path = $ra->{url};
                $root_path =~ s#^\Q$ra->{repos_root}\E(/|$)##;
                foreach my $path (keys %$fetch) {
                        my $ref_id = $fetch->{$path};
                        my $gs = Git::SVN->new($ref_id, $repo_id, $path);

                        # make sure we can read when connecting to
                        # a higher level of a repository
                        my ($last_rev, undef) = $gs->last_rev_commit;
                        if (!defined $last_rev) {
                                $last_rev = eval {
                                        $root_ra->get_latest_revnum;
                                };
                                next if $@;
                        }
                        my $new = $root_path;
                        $new .= length $path ? "/$path" : '';
                        eval {
                                $root_ra->get_log([$new], $last_rev, $last_rev,
                                                  0, 0, 1, sub { });
                        };
                        next if $@;
                        $new_urls->{$ra->{repos_root}}->{$new} =
                                { ref_id => $ref_id,
                                  old_repo_id => $repo_id,
                                  old_path => $path };
                }
        }

        my @emptied;
        foreach my $url (keys %$new_urls) {
                # see if we can re-use an existing [svn-remote "repo_id"]
                # instead of creating a(n ugly) new section:
                my $repo_id = $root_repos->{$url} || $url;

                my $fetch = $new_urls->{$url};
                foreach my $path (keys %$fetch) {
                        my $x = $fetch->{$path};
                        Git::SVN->init($url, $path, $repo_id, $x->{ref_id});
                        my $pfx = "svn-remote.$x->{old_repo_id}";

                        my $old_fetch = quotemeta("$x->{old_path}:".
                                                  "$x->{ref_id}");
                        command_noisy(qw/config --unset/,
                                      "$pfx.fetch", '^'. $old_fetch . '$');
                        delete $r->{$x->{old_repo_id}}->
                               {fetch}->{$x->{old_path}};
                        if (!keys %{$r->{$x->{old_repo_id}}->{fetch}}) {
                                command_noisy(qw/config --unset/,
                                              "$pfx.url");
                                push @emptied, $x->{old_repo_id}
                        }
                }
        }
        if (@emptied) {
                my $file = $ENV{GIT_CONFIG} || "$ENV{GIT_DIR}/config";
                print STDERR <<EOF;
The following [svn-remote] sections in your config file ($file) are empty
and can be safely removed:
EOF
                print STDERR "[svn-remote \"$_\"]\n" foreach @emptied;
        }
}

sub migration_check {
        migrate_from_v0();
        migrate_from_v1();
        migrate_from_v2();
        minimize_connections() if $_minimize;
}

package Git::IndexInfo;
use strict;
use warnings;
use Git qw/command_input_pipe command_close_pipe/;

sub new {
        my ($class) = @_;
        my ($gui, $ctx) = command_input_pipe(qw/update-index -z --index-info/);
        bless { gui => $gui, ctx => $ctx, nr => 0}, $class;
}

sub remove {
        my ($self, $path) = @_;
        if (print { $self->{gui} } '0 ', 0 x 40, "\t", $path, "\0") {
                return ++$self->{nr};
        }
        undef;
}

sub update {
        my ($self, $mode, $hash, $path) = @_;
        if (print { $self->{gui} } $mode, ' ', $hash, "\t", $path, "\0") {
                return ++$self->{nr};
        }
        undef;
}

sub DESTROY {
        my ($self) = @_;
        command_close_pipe($self->{gui}, $self->{ctx});
}

package Git::SVN::GlobSpec;
use strict;
use warnings;

sub new {
        my ($class, $glob, $pattern_ok) = @_;
        my $re = $glob;
        $re =~ s!/+$!!g; # no need for trailing slashes
        my (@left, @right, @patterns);
        my $state = "left";
        my $die_msg = "Only one set of wildcard directories " .
                                "(e.g. '*' or '*/*/*') is supported: '$glob'\n";
        for my $part (split(m|/|, $glob)) {
                if ($part =~ /\*/ && $part ne "*") {
                        die "Invalid pattern in '$glob': $part\n";
                } elsif ($pattern_ok && $part =~ /[{}]/ &&
                         $part !~ /^\{[^{}]+\}/) {
                        die "Invalid pattern in '$glob': $part\n";
                }
                if ($part eq "*") {
                        die $die_msg if $state eq "right";
                        $state = "pattern";
                        push(@patterns, "[^/]*");
                } elsif ($pattern_ok && $part =~ /^\{(.*)\}$/) {
                        die $die_msg if $state eq "right";
                        $state = "pattern";
                        my $p = quotemeta($1);
                        $p =~ s/\\,/|/g;
                        push(@patterns, "(?:$p)");
                } else {
                        if ($state eq "left") {
                                push(@left, $part);
                        } else {
                                push(@right, $part);
                                $state = "right";
                        }
                }
        }
        my $depth = @patterns;
        if ($depth == 0) {
                die "One '*' is needed in glob: '$glob'\n";
        }
        my $left = join('/', @left);
        my $right = join('/', @right);
        $re = join('/', @patterns);
        $re = join('\/',
                   grep(length, quotemeta($left), "($re)", quotemeta($right)));
        my $left_re = qr/^\/\Q$left\E(\/|$)/;
        bless { left => $left, right => $right, left_regex => $left_re,
                regex => qr/$re/, glob => $glob, depth => $depth }, $class;
}

sub full_path {
        my ($self, $path) = @_;
        return (length $self->{left} ? "$self->{left}/" : '') .
               $path . (length $self->{right} ? "/$self->{right}" : '');
}

__END__

Data structures:


$remotes = { # returned by read_all_remotes()
        'svn' => {
                # svn-remote.svn.url=https://svn.musicpd.org
                url => 'https://svn.musicpd.org',
                # svn-remote.svn.fetch=mpd/trunk:trunk
                fetch => {
                        'mpd/trunk' => 'trunk',
                },
                # svn-remote.svn.tags=mpd/tags/*:tags/*
                tags => {
                        path => {
                                left => 'mpd/tags',
                                right => '',
                                regex => qr!mpd/tags/([^/]+)$!,
                                glob => 'tags/*',
                        },
                        ref => {
                                left => 'tags',
                                right => '',
                                regex => qr!tags/([^/]+)$!,
                                glob => 'tags/*',
                        },
                }
        }
};

$log_entry hashref as returned by libsvn_log_entry()
{
        log => 'whitespace-formatted log entry
',                                              # trailing newline is preserved
        revision => '8',                        # integer
        date => '2004-02-24T17:01:44.108345Z',  # commit date
        author => 'committer name'
};


# this is generated by generate_diff();
@mods = array of diff-index line hashes, each element represents one line
        of diff-index output

diff-index line ($m hash)
{
        mode_a => first column of diff-index output, no leading ':',
        mode_b => second column of diff-index output,
        sha1_b => sha1sum of the final blob,
        chg => change type [MCRADT],
        file_a => original file name of a file (iff chg is 'C' or 'R')
        file_b => new/current file name of a file (any chg)
}
;

# retval of read_url_paths{,_all}();
$l_map = {
        # repository root url
        'https://svn.musicpd.org' => {
                # repository path               # GIT_SVN_ID
                'mpd/trunk'             =>      'trunk',
                'mpd/tags/0.11.5'       =>      'tags/0.11.5',
        },
}

Notes:
        I don't trust the each() function on unless I created %hash myself
        because the internal iterator may not have started at base.