[PATCH] Make "git diff" work inside relative subdirectories

We always show the diff as an absolute path, but pathnames to diff are
taken relative to the current working directory (and if no pathnames are
given, the default ends up being all of the current working directory).

Note that "../xyz" also works, so you can do

	cd linux/drivers/char
	git diff ../block

and it will generate a diff of the linux/drivers/block changes.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 13 insertions, 4 deletions

diff --git a/diff-tree.c b/diff-tree.c
index 0dd3cdacb2..fc87902a3d 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -395,16 +395,25 @@ static int diff_tree_stdin(char *line)
 	return diff_tree_commit(commit, line);
 }
 
+static int count_paths(const char **paths)
+{
+	int i = 0;
+	while (*paths++)
+		i++;
+	return i;
+}
+
 static const char diff_tree_usage[] =
 "git-diff-tree [--stdin] [-m] [-s] [-v] [--pretty] [-t] "
 "[<common diff options>] <tree-ish> <tree-ish>"
 COMMON_DIFF_OPTIONS_HELP;
 
-int main(int argc, const char **argv)
+int main(int argc, char **argv)
 {
 	int nr_sha1;
 	char line[1000];
 	unsigned char sha1[2][20];
+	const char *prefix = setup_git_directory();
 
 	nr_sha1 = 0;
 	for (;;) {
@@ -523,11 +532,11 @@ int main(int argc, const char **argv)
 	if (find_copies_harder && detect_rename != DIFF_DETECT_COPY)
 		usage(diff_tree_usage);
 
-	if (argc > 0) {
+	paths = get_pathspec(prefix, argv);
+	if (paths) {
 		int i;
 
-		paths = argv;
-		nr_paths = argc;
+		nr_paths = count_paths(paths);
 		pathlens = xmalloc(nr_paths * sizeof(int));
 		for (i=0; i<nr_paths; i++)
 			pathlens[i] = strlen(paths[i]);