t3200: fix failure on case-insensitive filesystems

diff --git a/git-difftool.perl b/git-difftool.perl
index 663640d33cb99a98135b38b95947416b4a8d49b9..67802922ccc41fa2993c1bce4ea1a3d2899c7a40 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -13,9 +13,9 @@
 use 5.008;
 use strict;
 use warnings;
+use Error qw(:try);
 use File::Basename qw(dirname);
 use File::Copy;
-use File::Compare;
 use File::Find;
 use File::stat;
 use File::Path qw(mkpath rmtree);
@@ -88,14 +88,45 @@ sub use_wt_file
        my ($repo, $workdir, $file, $sha1, $symlinks) = @_;
        my $null_sha1 = '0' x 40;
 
-       if ($sha1 eq $null_sha1) {
-               return 1;
-       } elsif (not $symlinks) {
+       if ($sha1 ne $null_sha1 and not $symlinks) {
                return 0;
        }
 
        my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
-       return $sha1 eq $wt_sha1;
+       my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
+       return ($use, $wt_sha1);
+}
+
+sub changed_files
+{
+       my ($repo_path, $index, $worktree) = @_;
+       $ENV{GIT_INDEX_FILE} = $index;
+       $ENV{GIT_WORK_TREE} = $worktree;
+       my $must_unset_git_dir = 0;
+       if (not defined($ENV{GIT_DIR})) {
+               $must_unset_git_dir = 1;
+               $ENV{GIT_DIR} = $repo_path;
+       }
+
+       my @refreshargs = qw/update-index --really-refresh -q --unmerged/;
+       my @gitargs = qw/diff-files --name-only -z/;
+       try {
+               Git::command_oneline(@refreshargs);
+       } catch Git::Error::Command with {};
+
+       my $line = Git::command_oneline(@gitargs);
+       my @files;
+       if (defined $line) {
+               @files = split('\0', $line);
+       } else {
+               @files = ();
+       }
+
+       delete($ENV{GIT_INDEX_FILE});
+       delete($ENV{GIT_WORK_TREE});
+       delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
+
+       return map { $_ => 1 } @files;
 }
 
 sub setup_dir_diff
@@ -121,6 +152,7 @@ sub setup_dir_diff
        my $null_sha1 = '0' x 40;
        my $lindex = '';
        my $rindex = '';
+       my $wtindex = '';
        my %submodule;
        my %symlink;
        my @working_tree = ();
@@ -174,8 +206,12 @@ sub setup_dir_diff
                }
 
                if ($rmode ne $null_mode) {
-                       if (use_wt_file($repo, $workdir, $dst_path, $rsha1, $symlinks)) {
-                               push(@working_tree, $dst_path);
+                       my ($use, $wt_sha1) = use_wt_file($repo, $workdir,
+                                                         $dst_path, $rsha1,
+                                                         $symlinks);
+                       if ($use) {
+                               push @working_tree, $dst_path;
+                               $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
                        } else {
                                $rindex .= "$rmode $rsha1\t$dst_path\0";
                        }
@@ -218,6 +254,12 @@ sub setup_dir_diff
        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
        exit_cleanup($tmpdir, $rc) if $rc != 0;
 
+       $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
+       ($inpipe, $ctx) =
+               $repo->command_input_pipe(qw(update-index --info-only -z --index-info));
+       print($inpipe $wtindex);
+       $repo->command_close_pipe($inpipe, $ctx);
+
        # If $GIT_DIR was explicitly set just for the update/checkout
        # commands, then it should be unset before continuing.
        delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
@@ -390,19 +432,34 @@ sub dir_diff
        # should be copied back to the working tree.
        # Do not copy back files when symlinks are used and the
        # external tool did not replace the original link with a file.
+       #
+       # These hashes are loaded lazily since they aren't needed
+       # in the common case of --symlinks and the difftool updating
+       # files through the symlink.
+       my %wt_modified;
+       my %tmp_modified;
+       my $indices_loaded = 0;
+
        for my $file (@worktree) {
                next if $symlinks && -l "$b/$file";
                next if ! -f "$b/$file";
 
-               my $diff = compare("$b/$file", "$workdir/$file");
-               if ($diff == 0) {
-                       next;
-               } elsif ($diff == -1) {
-                       my $errmsg = "warning: Could not compare ";
-                       $errmsg += "'$b/$file' with '$workdir/$file'\n";
+               if (!$indices_loaded) {
+                       %wt_modified = changed_files($repo->repo_path(),
+                               "$tmpdir/wtindex", "$workdir");
+                       %tmp_modified = changed_files($repo->repo_path(),
+                               "$tmpdir/wtindex", "$b");
+                       $indices_loaded = 1;
+               }
+
+               if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
+                       my $errmsg = "warning: Both files modified: ";
+                       $errmsg .= "'$workdir/$file' and '$b/$file'.\n";
+                       $errmsg .= "warning: Working tree file has been left.\n";
+                       $errmsg .= "warning:\n";
                        warn $errmsg;
                        $error = 1;
-               } elsif ($diff == 1) {
+               } elsif (exists $tmp_modified{$file}) {
                        my $mode = stat("$b/$file")->mode;
                        copy("$b/$file", "$workdir/$file") or
                        exit_cleanup($tmpdir, 1);