[PATCH] Add --diff-filter= output restriction to diff-* family.

This is a halfway between debugging aid and a helper to write an
ultra-smart merge scripts.  The new option takes a string that
consists of a list of "status" letters, and limits the diff
output to only those classes of changes, with two exceptions:

 - A broken pair (aka "complete rewrite"), does not match D
   (deleted) or N (created).  Use B to look for them.

 - The letter "A" in the diff-filter string does not match
   anything itself, but causes the entire diff that contains
   selected patches to be output (this behaviour is similar to
   that of --pickaxe-all for the -S option).

For example,

    $ git-rev-list HEAD |
      git-diff-tree --stdin -s -v -B -C --diff-filter=BCR

shows a list of commits that have complete rewrite, copy, or
rename.

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

1 files changed, 5 insertions, 2 deletions

diff --git a/diff-files.c b/diff-files.c
index 5c895cca7..b6d972e06 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -17,6 +17,7 @@ static const char *pickaxe = NULL;
 static int pickaxe_opts = 0;
 static int diff_break_opt = -1;
 static const char *orderfile = NULL;
+static const char *diff_filter = NULL;
 static int silent = 0;
 
 static void show_unmerge(const char *path)
@@ -59,6 +60,8 @@ int main(int argc, const char **argv)
 			pickaxe = argv[1] + 2;
 		else if (!strncmp(argv[1], "-O", 2))
 			orderfile = argv[1] + 2;
+		else if (!strncmp(argv[1], "--diff-filter=", 14))
+			diff_filter = argv[1] + 14;
 		else if (!strcmp(argv[1], "--pickaxe-all"))
 			pickaxe_opts = DIFF_PICKAXE_ALL;
 		else if (!strncmp(argv[1], "-B", 2)) {
@@ -131,7 +134,7 @@ int main(int argc, const char **argv)
 		     detect_rename, diff_score_opt,
 		     pickaxe, pickaxe_opts,
 		     diff_break_opt,
-		     orderfile);
-	diff_flush(diff_output_format, 1);
+		     orderfile, diff_filter);
+	diff_flush(diff_output_format);
 	return 0;
 }