From af7b41c923677ff9291bab56ec7069922e37453b Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Tue, 31 May 2011 11:33:56 -0400
Subject: diff_tree: disable QUICK optimization with diff filter

We stop looking for changes early with QUICK, so our diff
queue contains only a subset of the changes. However, we
don't apply diff filters until later; it will appear at that
point as though there are no changes matching our filter,
when in reality we simply didn't keep looking for changes
long enough.

Commit 2cfe8a6 (diff --quiet: disable optimization when
--diff-filter=X is used, 2011-03-16) fixes this in some
cases by disabling the optimization when a filter is
present. However, it only tweaked run_diff_files, missing
the similar case in diff_tree. Thus the fix worked only for
diffing the working tree and index, but not between trees.

Noticed by Yasushi SHOJI.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4037-whitespace-status.sh b/t/t4037-whitespace-status.sh
index abc4934..3c728a3 100755
--- a/t/t4037-whitespace-status.sh
+++ b/t/t4037-whitespace-status.sh
@@ -67,4 +67,9 @@ test_expect_success 'diff-files --diff-filter --quiet' '
 	test_must_fail git diff-files --diff-filter=M --quiet
 '
 
+test_expect_success 'diff-tree --diff-filter --quiet' '
+	git commit -a -m "worktree state" &&
+	test_must_fail git diff-tree --diff-filter=M --quiet HEAD^ HEAD
+'
+
 test_done
diff --git a/tree-diff.c b/tree-diff.c
index 7d745b4..70bdb89 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -287,6 +287,7 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
 
 	for (;;) {
 		if (DIFF_OPT_TST(opt, QUICK) &&
+		    !opt->filter &&
 		    DIFF_OPT_TST(opt, HAS_CHANGES))
 			break;
 		if (opt->nr_paths) {
-- 
cgit v0.10.2-6-g49f6


From 28b9264dd6cbadcef8b3e48c24ffcb2893b668b3 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 31 May 2011 09:14:17 -0700
Subject: diff: futureproof "stop feeding the backend early" logic

Refactor the "do not stop feeding the backend early" logic into a small
helper function and use it in both run_diff_files() and diff_tree() that
has the stop-early optimization. We may later add other types of diffcore
transformation that require to look at the whole result like diff-filter
does, and having the logic in a single place is essential for longer term
maintainability.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-lib.c b/diff-lib.c
index bfa6503..869d8f0 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -73,9 +73,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		struct cache_entry *ce = active_cache[i];
 		int changed;
 
-		if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
-		    !revs->diffopt.filter &&
-		    DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
+		if (diff_can_quit_early(&revs->diffopt))
 			break;
 
 		if (!ce_path_match(ce, revs->prune_data))
diff --git a/diff.c b/diff.c
index 91d6ea2..ae6853f 100644
--- a/diff.c
+++ b/diff.c
@@ -3513,6 +3513,13 @@ int diff_result_code(struct diff_options *opt, int status)
 	return result;
 }
 
+int diff_can_quit_early(struct diff_options *opt)
+{
+	return (DIFF_OPT_TST(opt, QUICK) &&
+		!opt->filter &&
+		DIFF_OPT_TST(opt, HAS_CHANGES));
+}
+
 void diff_addremove(struct diff_options *options,
 		    int addremove, unsigned mode,
 		    const unsigned char *sha1,
diff --git a/diff.h b/diff.h
index a7e7ccb..b412ffb 100644
--- a/diff.h
+++ b/diff.h
@@ -170,6 +170,8 @@ extern void diff_tree_combined_merge(const unsigned char *sha1, int, struct rev_
 
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
 
+extern int diff_can_quit_early(struct diff_options *);
+
 extern void diff_addremove(struct diff_options *,
 			   int addremove,
 			   unsigned mode,
diff --git a/tree-diff.c b/tree-diff.c
index 70bdb89..33881d1 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -286,9 +286,7 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
 	int baselen = strlen(base);
 
 	for (;;) {
-		if (DIFF_OPT_TST(opt, QUICK) &&
-		    !opt->filter &&
-		    DIFF_OPT_TST(opt, HAS_CHANGES))
+		if (diff_can_quit_early(opt))
 			break;
 		if (opt->nr_paths) {
 			skip_uninteresting(t1, base, baselen, opt);
-- 
cgit v0.10.2-6-g49f6