1 files changed, 46 insertions, 34 deletions

diff --git a/diff.c b/diff.c
index 8e4a6a910..e9a8874d0 100644
--- a/diff.c
+++ b/diff.c
@@ -2845,8 +2845,9 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 		remove_tempfile_installed = 1;
 	}
 
-	if (!one->sha1_valid ||
-	    reuse_worktree_file(name, one->sha1, 1)) {
+	if (!S_ISGITLINK(one->mode) &&
+	    (!one->sha1_valid ||
+	     reuse_worktree_file(name, one->sha1, 1))) {
 		struct stat st;
 		if (lstat(name, &st) < 0) {
 			if (errno == ENOENT)
@@ -3599,14 +3600,6 @@ static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
 	return 0;
 }
 
-/* Used only by "diff-files" and "diff --no-index" */
-void handle_deprecated_show_diff_q(struct diff_options *opt)
-{
-	warning("'diff -q' and 'diff-files -q' are deprecated.");
-	warning("Use 'diff --diff-filter=d' instead to ignore deleted filepairs.");
-	parse_diff_filter_opt("d", opt);
-}
-
 static void enable_patch_output(int *fmt) {
 	*fmt &= ~DIFF_FORMAT_NO_OUTPUT;
 	*fmt |= DIFF_FORMAT_PATCH;
@@ -4697,6 +4690,38 @@ static int diff_filespec_is_identical(struct diff_filespec *one,
 	return !memcmp(one->data, two->data, one->size);
 }
 
+static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
+{
+	if (p->done_skip_stat_unmatch)
+		return p->skip_stat_unmatch_result;
+
+	p->done_skip_stat_unmatch = 1;
+	p->skip_stat_unmatch_result = 0;
+	/*
+	 * 1. Entries that come from stat info dirtiness
+	 *    always have both sides (iow, not create/delete),
+	 *    one side of the object name is unknown, with
+	 *    the same mode and size.  Keep the ones that
+	 *    do not match these criteria.  They have real
+	 *    differences.
+	 *
+	 * 2. At this point, the file is known to be modified,
+	 *    with the same mode and size, and the object
+	 *    name of one side is unknown.  Need to inspect
+	 *    the identical contents.
+	 */
+	if (!DIFF_FILE_VALID(p->one) || /* (1) */
+	    !DIFF_FILE_VALID(p->two) ||
+	    (p->one->sha1_valid && p->two->sha1_valid) ||
+	    (p->one->mode != p->two->mode) ||
+	    diff_populate_filespec(p->one, 1) ||
+	    diff_populate_filespec(p->two, 1) ||
+	    (p->one->size != p->two->size) ||
+	    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
+		p->skip_stat_unmatch_result = 1;
+	return p->skip_stat_unmatch_result;
+}
+
 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
 {
 	int i;
@@ -4707,27 +4732,7 @@ static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
 
-		/*
-		 * 1. Entries that come from stat info dirtiness
-		 *    always have both sides (iow, not create/delete),
-		 *    one side of the object name is unknown, with
-		 *    the same mode and size.  Keep the ones that
-		 *    do not match these criteria.  They have real
-		 *    differences.
-		 *
-		 * 2. At this point, the file is known to be modified,
-		 *    with the same mode and size, and the object
-		 *    name of one side is unknown.  Need to inspect
-		 *    the identical contents.
-		 */
-		if (!DIFF_FILE_VALID(p->one) || /* (1) */
-		    !DIFF_FILE_VALID(p->two) ||
-		    (p->one->sha1_valid && p->two->sha1_valid) ||
-		    (p->one->mode != p->two->mode) ||
-		    diff_populate_filespec(p->one, 1) ||
-		    diff_populate_filespec(p->two, 1) ||
-		    (p->one->size != p->two->size) ||
-		    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
+		if (diff_filespec_check_stat_unmatch(p))
 			diff_q(&outq, p);
 		else {
 			/*
@@ -4890,6 +4895,7 @@ void diff_change(struct diff_options *options,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
 	struct diff_filespec *one, *two;
+	struct diff_filepair *p;
 
 	if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
 	    is_submodule_ignored(concatpath, options))
@@ -4916,10 +4922,16 @@ void diff_change(struct diff_options *options,
 	fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
 	one->dirty_submodule = old_dirty_submodule;
 	two->dirty_submodule = new_dirty_submodule;
+	p = diff_queue(&diff_queued_diff, one, two);
 
-	diff_queue(&diff_queued_diff, one, two);
-	if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
-		DIFF_OPT_SET(options, HAS_CHANGES);
+	if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
+		return;
+
+	if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
+	    !diff_filespec_check_stat_unmatch(p))
+		return;
+
+	DIFF_OPT_SET(options, HAS_CHANGES);
 }
 
 struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)