Merge branch 'jk/difftool-dir-diff-edit-fix'

"git difftool --dir-diff" made symlinks to working tree files when
preparing a temporary directory structure, so that accidental edits
of these files in the difftool are reflected back to the working
tree, but the logic to decide when to do so was not quite right.

* jk/difftool-dir-diff-edit-fix:
difftool --dir-diff: symlink all files matching the working tree
difftool: avoid double slashes in symlink targets
git-difftool(1): fix formatting of --symlink description

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index e0e12e947034b3f690d7f103ee90e0bc1a21f926..8361e6e4e3d2d4829d3ce3c6f3ec4a2ac974e86e 100644 (file)
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -72,10 +72,12 @@ with custom merge tool commands and has the same value as `$MERGED`.
 --symlinks::
 --no-symlinks::
        'git difftool''s default behavior is create symlinks to the
-       working tree when run in `--dir-diff` mode.
+       working tree when run in `--dir-diff` mode and the right-hand
+       side of the comparison yields the same content as the file in
+       the working tree.
 +
-       Specifying `--no-symlinks` instructs 'git difftool' to create
-       copies instead.  `--no-symlinks` is the default on Windows.
+Specifying `--no-symlinks` instructs 'git difftool' to create copies
+instead.  `--no-symlinks` is the default on Windows.
 
 -x <command>::
 --extcmd=<command>::

diff --git a/git-difftool.perl b/git-difftool.perl
index 12231fbc6708971f6350006c710124bd369de7ab..663640d33cb99a98135b38b95947416b4a8d49b9 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -83,6 +83,21 @@ sub exit_cleanup
        exit($status | ($status >> 8));
 }
 
+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) {
+               return 0;
+       }
+
+       my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
+       return $sha1 eq $wt_sha1;
+}
+
 sub setup_dir_diff
 {
        my ($repo, $workdir, $symlinks) = @_;
@@ -159,10 +174,10 @@ sub setup_dir_diff
                }
 
                if ($rmode ne $null_mode) {
-                       if ($rsha1 ne $null_sha1) {
-                               $rindex .= "$rmode $rsha1\t$dst_path\0";
-                       } else {
+                       if (use_wt_file($repo, $workdir, $dst_path, $rsha1, $symlinks)) {
                                push(@working_tree, $dst_path);
+                       } else {
+                               $rindex .= "$rmode $rsha1\t$dst_path\0";
                        }
                }
        }
@@ -209,7 +224,9 @@ sub setup_dir_diff
        delete($ENV{GIT_INDEX_FILE});
 
        # Changes in the working tree need special treatment since they are
-       # not part of the index
+       # not part of the index. Remove any trailing slash from $workdir
+       # before starting to avoid double slashes in symlink targets.
+       $workdir =~ s|/$||;
        for my $file (@working_tree) {
                my $dir = dirname($file);
                unless (-d "$rdir/$dir") {

diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 3aab6e15000f57e76d05f70920525d5734e20ef7..c6d6b1c99fe98b7dc692eaf3828a08696bfb5e10 100755 (executable)
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -340,6 +340,28 @@ test_expect_success PERL 'difftool --dir-diff' '
        stdin_contains file <output
 '
 
+write_script .git/CHECK_SYMLINKS <<\EOF
+for f in file file2 sub/sub
+do
+       echo "$f"
+       readlink "$2/$f"
+done >actual
+EOF
+
+test_expect_success PERL,SYMLINKS 'difftool --dir-diff --symlink without unstaged changes' '
+       cat >expect <<-EOF &&
+       file
+       $(pwd)/file
+       file2
+       $(pwd)/file2
+       sub/sub
+       $(pwd)/sub/sub
+       EOF
+       git difftool --dir-diff --symlink \
+               --extcmd "./.git/CHECK_SYMLINKS" branch HEAD &&
+       test_cmp actual expect
+'
+
 test_expect_success PERL 'difftool --dir-diff ignores --prompt' '
        git difftool --dir-diff --prompt --extcmd ls branch >output &&
        stdin_contains sub <output &&