1 files changed, 135 insertions, 79 deletions

diff --git a/diff.c b/diff.c
index 2d0b5e33f9..7c59bfe2d0 100644
--- a/diff.c
+++ b/diff.c
@@ -30,6 +30,7 @@ static int diff_use_color_default = -1;
 static int diff_context_default = 3;
 static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
+static const char *diff_order_file_cfg;
 int diff_auto_refresh_index = 1;
 static int diff_mnemonic_prefix;
 static int diff_no_prefix;
@@ -201,6 +202,8 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		return git_config_string(&external_diff_cmd_cfg, var, value);
 	if (!strcmp(var, "diff.wordregex"))
 		return git_config_string(&diff_word_regex_cfg, var, value);
+	if (!strcmp(var, "diff.orderfile"))
+		return git_config_pathname(&diff_order_file_cfg, var, value);
 
 	if (!strcmp(var, "diff.ignoresubmodules"))
 		handle_ignore_submodules_arg(&default_diff_options, value);
@@ -235,7 +238,7 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
-	if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
+	if (starts_with(var, "diff.color.") || starts_with(var, "color.diff.")) {
 		int slot = parse_diff_color_slot(var, 11);
 		if (slot < 0)
 			return 0;
@@ -264,7 +267,7 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!prefixcmp(var, "submodule."))
+	if (starts_with(var, "submodule."))
 		return parse_submodule_config_option(var, value);
 
 	return git_default_config(var, value, cb);
@@ -669,7 +672,7 @@ static void emit_rewrite_diff(const char *name_a,
 	memset(&ecbdata, 0, sizeof(ecbdata));
 	ecbdata.color_diff = want_color(o->use_color);
 	ecbdata.found_changesp = &o->found_changes;
-	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
+	ecbdata.ws_rule = whitespace_rule(name_b);
 	ecbdata.opt = o;
 	if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 		mmfile_t mf1, mf2;
@@ -1215,7 +1218,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 			diff_words_append(line, len,
 					  &ecbdata->diff_words->plus);
 			return;
-		} else if (!prefixcmp(line, "\\ ")) {
+		} else if (starts_with(line, "\\ ")) {
 			/*
 			 * Eat the "no newline at eof" marker as if we
 			 * saw a "+" or "-" line with nothing on it,
@@ -1683,9 +1686,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 		del = deleted;
 
 		if (graph_width <= max_change) {
-			int total = add + del;
-
-			total = scale_linear(add + del, graph_width, max_change);
+			int total = scale_linear(add + del, graph_width, max_change);
 			if (total < 2 && add && del)
 				/* width >= 2 due to the sanity check */
 				total = 2;
@@ -2254,7 +2255,8 @@ static void builtin_diff(const char *name_a,
 			(!two->mode || S_ISGITLINK(two->mode))) {
 		const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
 		const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
-		show_submodule_summary(o->file, one ? one->path : two->path,
+		show_submodule_summary(o->file, one->path ? one->path : two->path,
+				line_prefix,
 				one->sha1, two->sha1, two->dirty_submodule,
 				meta, del, add, reset);
 		return;
@@ -2373,7 +2375,7 @@ static void builtin_diff(const char *name_a,
 		ecbdata.label_path = lbl;
 		ecbdata.color_diff = want_color(o->use_color);
 		ecbdata.found_changesp = &o->found_changes;
-		ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
+		ecbdata.ws_rule = whitespace_rule(name_b);
 		if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
 			check_blank_at_eof(&mf1, &mf2, &ecbdata);
 		ecbdata.opt = o;
@@ -2388,9 +2390,9 @@ static void builtin_diff(const char *name_a,
 			xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 		if (!diffopts)
 			;
-		else if (!prefixcmp(diffopts, "--unified="))
+		else if (starts_with(diffopts, "--unified="))
 			xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
-		else if (!prefixcmp(diffopts, "-u"))
+		else if (starts_with(diffopts, "-u"))
 			xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 		if (o->word_diff)
 			init_diff_words_data(&ecbdata, o, one, two);
@@ -2585,7 +2587,7 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
  */
 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
 {
-	struct cache_entry *ce;
+	const struct cache_entry *ce;
 	struct stat st;
 	int pos, len;
 
@@ -2676,6 +2678,14 @@ static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 int diff_populate_filespec(struct diff_filespec *s, int size_only)
 {
 	int err = 0;
+	/*
+	 * demote FAIL to WARN to allow inspecting the situation
+	 * instead of refusing.
+	 */
+	enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
+				    ? SAFE_CRLF_WARN
+				    : safe_crlf);
+
 	if (!DIFF_FILE_VALID(s))
 		die("internal error: asking to populate invalid file.");
 	if (S_ISDIR(s->mode))
@@ -2731,7 +2741,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 		/*
 		 * Convert from working tree format to canonical git format
 		 */
-		if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
+		if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
 			size_t size = 0;
 			munmap(s->data, s->size);
 			s->should_munmap = 0;
@@ -2892,11 +2902,16 @@ static void run_external_diff(const char *pgm,
 			      struct diff_filespec *one,
 			      struct diff_filespec *two,
 			      const char *xfrm_msg,
-			      int complete_rewrite)
+			      int complete_rewrite,
+			      struct diff_options *o)
 {
 	const char *spawn_arg[10];
 	int retval;
 	const char **arg = &spawn_arg[0];
+	struct diff_queue_struct *q = &diff_queued_diff;
+	const char *env[3] = { NULL };
+	char env_counter[50];
+	char env_total[50];
 
 	if (one && two) {
 		struct diff_tempfile *temp_one, *temp_two;
@@ -2921,7 +2936,14 @@ static void run_external_diff(const char *pgm,
 	}
 	*arg = NULL;
 	fflush(NULL);
-	retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
+
+	env[0] = env_counter;
+	snprintf(env_counter, sizeof(env_counter), "GIT_DIFF_PATH_COUNTER=%d",
+		 ++o->diff_path_counter);
+	env[1] = env_total;
+	snprintf(env_total, sizeof(env_total), "GIT_DIFF_PATH_TOTAL=%d", q->nr);
+
+	retval = run_command_v_opt_cd_env(spawn_arg, RUN_USING_SHELL, NULL, env);
 	remove_tempfile();
 	if (retval) {
 		fprintf(stderr, "external diff died, stopping at %s.\n", name);
@@ -3035,7 +3057,7 @@ static void run_diff_cmd(const char *pgm,
 
 	if (pgm) {
 		run_external_diff(pgm, name, other, one, two, xfrm_msg,
-				  complete_rewrite);
+				  complete_rewrite, o);
 		return;
 	}
 	if (one && two)
@@ -3200,6 +3222,8 @@ void diff_setup(struct diff_options *options)
 	options->detect_rename = diff_detect_rename_default;
 	options->xdl_opts |= diff_algorithm;
 
+	options->orderfile = diff_order_file_cfg;
+
 	if (diff_no_prefix) {
 		options->a_prefix = options->b_prefix = "";
 	} else if (!diff_mnemonic_prefix) {
@@ -3212,6 +3236,9 @@ void diff_setup_done(struct diff_options *options)
 {
 	int count = 0;
 
+	if (options->set_default)
+		options->set_default(options);
+
 	if (options->output_format & DIFF_FORMAT_NAME)
 		count++;
 	if (options->output_format & DIFF_FORMAT_NAME_STATUS)
@@ -3307,6 +3334,8 @@ void diff_setup_done(struct diff_options *options)
 		options->output_format = DIFF_FORMAT_NO_OUTPUT;
 		DIFF_OPT_SET(options, EXIT_WITH_STATUS);
 	}
+
+	options->diff_path_counter = 0;
 }
 
 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
@@ -3381,10 +3410,10 @@ int parse_long_opt(const char *opt, const char **argv,
 	if (arg[0] != '-' || arg[1] != '-')
 		return 0;
 	arg += strlen("--");
-	if (prefixcmp(arg, opt))
+	if (!starts_with(arg, opt))
 		return 0;
 	arg += strlen(opt);
-	if (*arg == '=') { /* sticked form: --option=value */
+	if (*arg == '=') { /* stuck form: --option=value */
 		*optarg = arg + 1;
 		return 1;
 	}
@@ -3412,7 +3441,7 @@ static int stat_opt(struct diff_options *options, const char **av)
 
 	switch (*arg) {
 	case '-':
-		if (!prefixcmp(arg, "-width")) {
+		if (starts_with(arg, "-width")) {
 			arg += strlen("-width");
 			if (*arg == '=')
 				width = strtoul(arg + 1, &end, 10);
@@ -3422,7 +3451,7 @@ static int stat_opt(struct diff_options *options, const char **av)
 				width = strtoul(av[1], &end, 10);
 				argcount = 2;
 			}
-		} else if (!prefixcmp(arg, "-name-width")) {
+		} else if (starts_with(arg, "-name-width")) {
 			arg += strlen("-name-width");
 			if (*arg == '=')
 				name_width = strtoul(arg + 1, &end, 10);
@@ -3432,7 +3461,7 @@ static int stat_opt(struct diff_options *options, const char **av)
 				name_width = strtoul(av[1], &end, 10);
 				argcount = 2;
 			}
-		} else if (!prefixcmp(arg, "-graph-width")) {
+		} else if (starts_with(arg, "-graph-width")) {
 			arg += strlen("-graph-width");
 			if (*arg == '=')
 				graph_width = strtoul(arg + 1, &end, 10);
@@ -3442,7 +3471,7 @@ static int stat_opt(struct diff_options *options, const char **av)
 				graph_width = strtoul(av[1], &end, 10);
 				argcount = 2;
 			}
-		} else if (!prefixcmp(arg, "-count")) {
+		} else if (starts_with(arg, "-count")) {
 			arg += strlen("-count");
 			if (*arg == '=')
 				count = strtoul(arg + 1, &end, 10);
@@ -3570,6 +3599,11 @@ static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
 	return 0;
 }
 
+static void enable_patch_output(int *fmt) {
+	*fmt &= ~DIFF_FORMAT_NO_OUTPUT;
+	*fmt |= DIFF_FORMAT_PATCH;
+}
+
 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
 	const char *arg = av[0];
@@ -3577,29 +3611,29 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	int argcount;
 
 	/* Output format options */
-	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
-		options->output_format |= DIFF_FORMAT_PATCH;
-	else if (opt_arg(arg, 'U', "unified", &options->context))
-		options->output_format |= DIFF_FORMAT_PATCH;
+	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
+	    || opt_arg(arg, 'U', "unified", &options->context))
+		enable_patch_output(&options->output_format);
 	else if (!strcmp(arg, "--raw"))
 		options->output_format |= DIFF_FORMAT_RAW;
-	else if (!strcmp(arg, "--patch-with-raw"))
-		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
-	else if (!strcmp(arg, "--numstat"))
+	else if (!strcmp(arg, "--patch-with-raw")) {
+		enable_patch_output(&options->output_format);
+		options->output_format |= DIFF_FORMAT_RAW;
+	} else if (!strcmp(arg, "--numstat"))
 		options->output_format |= DIFF_FORMAT_NUMSTAT;
 	else if (!strcmp(arg, "--shortstat"))
 		options->output_format |= DIFF_FORMAT_SHORTSTAT;
 	else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
 		return parse_dirstat_opt(options, "");
-	else if (!prefixcmp(arg, "-X"))
+	else if (starts_with(arg, "-X"))
 		return parse_dirstat_opt(options, arg + 2);
-	else if (!prefixcmp(arg, "--dirstat="))
+	else if (starts_with(arg, "--dirstat="))
 		return parse_dirstat_opt(options, arg + 10);
 	else if (!strcmp(arg, "--cumulative"))
 		return parse_dirstat_opt(options, "cumulative");
 	else if (!strcmp(arg, "--dirstat-by-file"))
 		return parse_dirstat_opt(options, "files");
-	else if (!prefixcmp(arg, "--dirstat-by-file=")) {
+	else if (starts_with(arg, "--dirstat-by-file=")) {
 		parse_dirstat_opt(options, "files");
 		return parse_dirstat_opt(options, arg + 18);
 	}
@@ -3607,25 +3641,26 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->output_format |= DIFF_FORMAT_CHECKDIFF;
 	else if (!strcmp(arg, "--summary"))
 		options->output_format |= DIFF_FORMAT_SUMMARY;
-	else if (!strcmp(arg, "--patch-with-stat"))
-		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
-	else if (!strcmp(arg, "--name-only"))
+	else if (!strcmp(arg, "--patch-with-stat")) {
+		enable_patch_output(&options->output_format);
+		options->output_format |= DIFF_FORMAT_DIFFSTAT;
+	} else if (!strcmp(arg, "--name-only"))
 		options->output_format |= DIFF_FORMAT_NAME;
 	else if (!strcmp(arg, "--name-status"))
 		options->output_format |= DIFF_FORMAT_NAME_STATUS;
-	else if (!strcmp(arg, "-s"))
+	else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
 		options->output_format |= DIFF_FORMAT_NO_OUTPUT;
-	else if (!prefixcmp(arg, "--stat"))
+	else if (starts_with(arg, "--stat"))
 		/* --stat, --stat-width, --stat-name-width, or --stat-count */
 		return stat_opt(options, av);
 
 	/* renames options */
-	else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
+	else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
 		 !strcmp(arg, "--break-rewrites")) {
 		if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
 			return error("invalid argument to -B: %s", arg+2);
 	}
-	else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
+	else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
 		 !strcmp(arg, "--find-renames")) {
 		if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 			return error("invalid argument to -M: %s", arg+2);
@@ -3634,7 +3669,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
 		options->irreversible_delete = 1;
 	}
-	else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
+	else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
 		 !strcmp(arg, "--find-copies")) {
 		if (options->detect_rename == DIFF_DETECT_COPY)
 			DIFF_OPT_SET(options, FIND_COPIES_HARDER);
@@ -3650,7 +3685,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_OPT_CLR(options, RENAME_EMPTY);
 	else if (!strcmp(arg, "--relative"))
 		DIFF_OPT_SET(options, RELATIVE_NAME);
-	else if (!prefixcmp(arg, "--relative=")) {
+	else if (starts_with(arg, "--relative=")) {
 		DIFF_OPT_SET(options, RELATIVE_NAME);
 		options->prefix = arg + 11;
 	}
@@ -3666,6 +3701,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
 	else if (!strcmp(arg, "--ignore-space-at-eol"))
 		DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
+	else if (!strcmp(arg, "--ignore-blank-lines"))
+		DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
 	else if (!strcmp(arg, "--patience"))
 		options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 	else if (!strcmp(arg, "--histogram"))
@@ -3684,7 +3721,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 
 	/* flags options */
 	else if (!strcmp(arg, "--binary")) {
-		options->output_format |= DIFF_FORMAT_PATCH;
+		enable_patch_output(&options->output_format);
 		DIFF_OPT_SET(options, BINARY);
 	}
 	else if (!strcmp(arg, "--full-index"))
@@ -3701,7 +3738,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_OPT_CLR(options, FOLLOW_RENAMES);
 	else if (!strcmp(arg, "--color"))
 		options->use_color = 1;
-	else if (!prefixcmp(arg, "--color=")) {
+	else if (starts_with(arg, "--color=")) {
 		int value = git_config_colorbool(NULL, arg+8);
 		if (value < 0)
 			return error("option `color' expects \"always\", \"auto\", or \"never\"");
@@ -3713,7 +3750,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
 	}
-	else if (!prefixcmp(arg, "--color-words=")) {
+	else if (starts_with(arg, "--color-words=")) {
 		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
 		options->word_regex = arg + 14;
@@ -3722,7 +3759,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		if (options->word_diff == DIFF_WORDS_NONE)
 			options->word_diff = DIFF_WORDS_PLAIN;
 	}
-	else if (!prefixcmp(arg, "--word-diff=")) {
+	else if (starts_with(arg, "--word-diff=")) {
 		const char *type = arg + 12;
 		if (!strcmp(type, "plain"))
 			options->word_diff = DIFF_WORDS_PLAIN;
@@ -3758,12 +3795,12 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--ignore-submodules")) {
 		DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
 		handle_ignore_submodules_arg(options, "all");
-	} else if (!prefixcmp(arg, "--ignore-submodules=")) {
+	} else if (starts_with(arg, "--ignore-submodules=")) {
 		DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
 		handle_ignore_submodules_arg(options, arg + 20);
 	} else if (!strcmp(arg, "--submodule"))
 		DIFF_OPT_SET(options, SUBMODULE_LOG);
-	else if (!prefixcmp(arg, "--submodule="))
+	else if (starts_with(arg, "--submodule="))
 		return parse_submodule_opt(options, arg + 12);
 
 	/* misc options */
@@ -3799,7 +3836,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	}
 	else if (!strcmp(arg, "--abbrev"))
 		options->abbrev = DEFAULT_ABBREV;
-	else if (!prefixcmp(arg, "--abbrev=")) {
+	else if (starts_with(arg, "--abbrev=")) {
 		options->abbrev = strtoul(arg + 9, NULL, 10);
 		if (options->abbrev < MINIMUM_ABBREV)
 			options->abbrev = MINIMUM_ABBREV;
@@ -3881,15 +3918,15 @@ static int diff_scoreopt_parse(const char *opt)
 	cmd = *opt++;
 	if (cmd == '-') {
 		/* convert the long-form arguments into short-form versions */
-		if (!prefixcmp(opt, "break-rewrites")) {
+		if (starts_with(opt, "break-rewrites")) {
 			opt += strlen("break-rewrites");
 			if (*opt == 0 || *opt++ == '=')
 				cmd = 'B';
-		} else if (!prefixcmp(opt, "find-copies")) {
+		} else if (starts_with(opt, "find-copies")) {
 			opt += strlen("find-copies");
 			if (*opt == 0 || *opt++ == '=')
 				cmd = 'C';
-		} else if (!prefixcmp(opt, "find-renames")) {
+		} else if (starts_with(opt, "find-renames")) {
 			opt += strlen("find-renames");
 			if (*opt == 0 || *opt++ == '=')
 				cmd = 'M';
@@ -4094,9 +4131,9 @@ void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
 		DIFF_FILE_VALID(s) ? "valid" : "invalid",
 		s->mode,
 		s->sha1_valid ? sha1_to_hex(s->sha1) : "");
-	fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+	fprintf(stderr, "queue[%d] %s size %lu\n",
 		x, one ? one : "",
-		s->size, s->xfrm_flags);
+		s->size);
 }
 
 void diff_debug_filepair(const struct diff_filepair *p, int i)
@@ -4299,7 +4336,7 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
 	int new_len;
 
 	/* Ignore line numbers when computing the SHA1 of the patch */
-	if (!prefixcmp(line, "@@ -"))
+	if (starts_with(line, "@@ -"))
 		return;
 
 	new_len = remove_space(line, len);
@@ -4526,7 +4563,7 @@ void diff_flush(struct diff_options *options)
 	    DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
 		/*
 		 * run diff_flush_patch for the exit status. setting
-		 * options->file to /dev/null should be safe, becaue we
+		 * options->file to /dev/null should be safe, because we
 		 * aren't supposed to produce any output anyway.
 		 */
 		if (options->close_file)
@@ -4652,6 +4689,38 @@ 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;
@@ -4662,27 +4731,7 @@ 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 {
 			/*
@@ -4845,6 +4894,7 @@ 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))
@@ -4871,10 +4921,16 @@ 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)