difftool: fix argument handling in subdirs

When in a subdirectory of a repository, path arguments should be
interpreted relative to the current directory not the root of the
working tree.

The Git::repository object passed into setup_dir_diff() is configured to
handle this correctly but we create a new Git::repository here without
setting the WorkingSubdir argument.  By simply using the existing
repository, path arguments are handled relative to the current
directory.

Reported-by: Bernhard Kirchen <[email protected]>
Signed-off-by: John Keeping <[email protected]>
Acked-by: David Aguilar <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: johnkeeping

git-difftool.perl

@@ -115,16 +115,9 @@ sub setup_dir_diff
 {
 	my ($repo, $workdir, $symlinks) = @_;
 
-	# Run the diff; exit immediately if no diff found
-	# 'Repository' and 'WorkingCopy' must be explicitly set to insure that
-	# if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
-	# by Git->repository->command*.
 	my $repo_path = $repo->repo_path();
-	my %repo_args = (Repository => $repo_path, WorkingCopy => $workdir);
-	my $diffrepo = Git->repository(%repo_args);
-
 	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
-	my $diffrtn = $diffrepo->command_oneline(@gitargs);
+	my $diffrtn = $repo->command_oneline(@gitargs);
 	exit(0) unless defined($diffrtn);
 
 	# Build index info for left and right sides of the diff
@@ -176,12 +169,12 @@ sub setup_dir_diff
 
 		if ($lmode eq $symlink_mode) {
 			$symlink{$src_path}{left} =
-				$diffrepo->command_oneline('show', "$lsha1");
+				$repo->command_oneline('show', "$lsha1");
 		}
 
 		if ($rmode eq $symlink_mode) {
 			$symlink{$dst_path}{right} =
-				$diffrepo->command_oneline('show', "$rsha1");
+				$repo->command_oneline('show', "$rsha1");
 		}
 
 		if ($lmode ne $null_mode and $status !~ /^C/) {