expose a helper function peel_to_type().

diff --git a/git-cvsexportcommit.perl b/git-cvsexportcommit.perl
index f284c88a46b5cc7d6e75b78346829ce03e60b060..2a8ad1e9f4cbc2c21b83fd72fae1e0d2e582fbdc 100755 (executable)
--- a/git-cvsexportcommit.perl
+++ b/git-cvsexportcommit.perl
@@ -1,28 +1,41 @@
 #!/usr/bin/perl -w
 
-# Known limitations:
-# - does not propagate permissions
-# - error handling has not been extensively tested
-#
-
 use strict;
 use Getopt::Std;
 use File::Temp qw(tempdir);
 use Data::Dumper;
 use File::Basename qw(basename dirname);
+use File::Spec;
 
-unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
-    die "GIT_DIR is not defined or is unreadable";
-}
-
-our ($opt_h, $opt_P, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m, $opt_d, $opt_u);
+our ($opt_h, $opt_P, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m, $opt_d, $opt_u, $opt_w);
 
-getopts('uhPpvcfam:d:');
+getopts('uhPpvcfam:d:w:');
 
 $opt_h && usage();
 
 die "Need at least one commit identifier!" unless @ARGV;
 
+if ($opt_w) {
+       # Remember where GIT_DIR is before changing to CVS checkout
+       unless ($ENV{GIT_DIR}) {
+               # No GIT_DIR set. Figure it out for ourselves
+               my $gd =`git-rev-parse --git-dir`;
+               chomp($gd);
+               $ENV{GIT_DIR} = $gd;
+       }
+       # Make sure GIT_DIR is absolute
+       $ENV{GIT_DIR} = File::Spec->rel2abs($ENV{GIT_DIR});
+
+       if (! -d $opt_w."/CVS" ) {
+               die "$opt_w is not a CVS checkout";
+       }
+       chdir $opt_w or die "Cannot change to CVS checkout at $opt_w";
+}
+unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
+    die "GIT_DIR is not defined or is unreadable";
+}
+
+
 my @cvs;
 if ($opt_d) {
        @cvs = ('cvs', '-d', $opt_d);
@@ -82,6 +95,7 @@
     }
 }
 
+my $noparent = "0000000000000000000000000000000000000000";
 if ($parent) {
     my $found;
     # double check that it's a valid parent
@@ -95,8 +109,10 @@
 } else { # we don't have a parent from the cmdline...
     if (@parents == 1) { # it's safe to get it from the commit
        $parent = $parents[0];
-    } else { # or perhaps not!
-       die "This commit has more than one parent -- please name the parent you want to use explicitly";
+    } elsif (@parents == 0) { # there is no parent
+        $parent = $noparent;
+    } else { # cannot choose automatically from multiple parents
+        die "This commit has more than one parent -- please name the parent you want to use explicitly";
     }
 }
 
@@ -116,7 +132,11 @@
 }
 close MSG;
 
-`git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
+if ($parent eq $noparent) {
+    `git-diff-tree --binary -p --root $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
+} else {
+    `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
+}
 
 ## apply non-binary changes
 
@@ -174,11 +194,11 @@
 my %cvsstat;
 if (@canstatusfiles) {
     if ($opt_u) {
-      my @updated = safe_pipe_capture(@cvs, 'update', @canstatusfiles);
+      my @updated = xargs_safe_pipe_capture([@cvs, 'update'], @canstatusfiles);
       print @updated;
     }
     my @cvsoutput;
-    @cvsoutput= safe_pipe_capture(@cvs, 'status', @canstatusfiles);
+    @cvsoutput = xargs_safe_pipe_capture([@cvs, 'status'], @canstatusfiles);
     my $matchcount = 0;
     foreach my $l (@cvsoutput) {
         chomp $l;
@@ -267,13 +287,14 @@
     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
     print "using a patch program. After applying the patch and resolving the\n";
     print "problems you may commit using:";
+    print "\n    cd \"$opt_w\"" if $opt_w;
     print "\n    $cmd\n\n";
     exit(1);
 }
 
 if ($opt_c) {
     print "Autocommit\n  $cmd\n";
-    print safe_pipe_capture(@cvs, 'commit', '-F', '.msg', @files);
+    print xargs_safe_pipe_capture([@cvs, 'commit', '-F', '.msg'], @files);
     if ($?) {
        die "Exiting: The commit did not succeed";
     }
@@ -294,7 +315,7 @@
 
 sub usage {
        print STDERR <<END;
-Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
+Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-u] [-w cvsworkdir] [-m msgprefix] [ parent ] commit
 END
        exit(1);
 }
@@ -313,15 +334,24 @@ sub safe_pipe_capture {
     return wantarray ? @output : join('',@output);
 }
 
-sub safe_pipe_capture_blob {
-    my $output;
-    if (my $pid = open my $child, '-|') {
-        local $/;
-       undef $/;
-       $output = (<$child>);
-       close $child or die join(' ',@_).": $! $?";
-    } else {
-       exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
-    }
-    return $output;
+sub xargs_safe_pipe_capture {
+       my $MAX_ARG_LENGTH = 65536;
+       my $cmd = shift;
+       my @output;
+       my $output;
+       while(@_) {
+               my @args;
+               my $length = 0;
+               while(@_ && $length < $MAX_ARG_LENGTH) {
+                       push @args, shift;
+                       $length += length($args[$#args]);
+               }
+               if (wantarray) {
+                       push @output, safe_pipe_capture(@$cmd, @args);
+               }
+               else {
+                       $output .= safe_pipe_capture(@$cmd, @args);
+               }
+       }
+       return wantarray ? @output : $output;
 }