1 files changed, 230 insertions, 136 deletions

diff --git a/diff.c b/diff.c
index 266112ca61..f66716fab4 100644
--- a/diff.c
+++ b/diff.c
@@ -16,6 +16,7 @@
 #include "submodule.h"
 #include "ll-merge.h"
 #include "string-list.h"
+#include "argv-array.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
@@ -30,6 +31,7 @@ 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 +203,8 @@ 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 +239,7 @@ 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 +268,7 @@ 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 +673,7 @@ 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 +1219,7 @@ 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,
@@ -1358,11 +1362,7 @@ static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 {
 	struct diffstat_file *x;
 	x = xcalloc(sizeof (*x), 1);
-	if (diffstat->nr == diffstat->alloc) {
-		diffstat->alloc = alloc_nr(diffstat->alloc);
-		diffstat->files = xrealloc(diffstat->files,
-				diffstat->alloc * sizeof(x));
-	}
+	ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
 	diffstat->files[diffstat->nr++] = x;
 	if (name_b) {
 		x->from_name = xstrdup(name_a);
@@ -1462,20 +1462,12 @@ int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
 	 * but nothing about added/removed lines? Is this a bug in Git?").
 	 */
 	if (insertions || deletions == 0) {
-		/*
-		 * TRANSLATORS: "+" in (+) is a line addition marker;
-		 * do not translate it.
-		 */
 		strbuf_addf(&sb,
 			    (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
 			    insertions);
 	}
 
 	if (deletions || insertions == 0) {
-		/*
-		 * TRANSLATORS: "-" in (-) is a line removal marker;
-		 * do not translate it.
-		 */
 		strbuf_addf(&sb,
 			    (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
 			    deletions);
@@ -2252,7 +2244,7 @@ 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);
@@ -2372,7 +2364,7 @@ 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;
@@ -2387,9 +2379,9 @@ 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);
@@ -2842,8 +2834,9 @@ 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)
@@ -2887,6 +2880,16 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 	return temp;
 }
 
+static void add_external_diff_name(struct argv_array *argv,
+				   const char *name,
+				   struct diff_filespec *df)
+{
+	struct diff_tempfile *temp = prepare_temp_file(name, df);
+	argv_array_push(argv, temp->name);
+	argv_array_push(argv, temp->hex);
+	argv_array_push(argv, temp->mode);
+}
+
 /* An external diff command takes:
  *
  * diff-cmd name infile1 infile1-sha1 infile1-mode \
@@ -2899,41 +2902,36 @@ 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 argv_array argv = ARGV_ARRAY_INIT;
+	struct argv_array env = ARGV_ARRAY_INIT;
+	struct diff_queue_struct *q = &diff_queued_diff;
+
+	argv_array_push(&argv, pgm);
+	argv_array_push(&argv, name);
 
 	if (one && two) {
-		struct diff_tempfile *temp_one, *temp_two;
-		const char *othername = (other ? other : name);
-		temp_one = prepare_temp_file(name, one);
-		temp_two = prepare_temp_file(othername, two);
-		*arg++ = pgm;
-		*arg++ = name;
-		*arg++ = temp_one->name;
-		*arg++ = temp_one->hex;
-		*arg++ = temp_one->mode;
-		*arg++ = temp_two->name;
-		*arg++ = temp_two->hex;
-		*arg++ = temp_two->mode;
-		if (other) {
-			*arg++ = other;
-			*arg++ = xfrm_msg;
+		add_external_diff_name(&argv, name, one);
+		if (!other)
+			add_external_diff_name(&argv, name, two);
+		else {
+			add_external_diff_name(&argv, other, two);
+			argv_array_push(&argv, other);
+			argv_array_push(&argv, xfrm_msg);
 		}
-	} else {
-		*arg++ = pgm;
-		*arg++ = name;
 	}
-	*arg = NULL;
-	fflush(NULL);
-	retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
+
+	argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
+	argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
+
+	if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
+		die(_("external diff died, stopping at %s"), name);
+
 	remove_tempfile();
-	if (retval) {
-		fprintf(stderr, "external diff died, stopping at %s.\n", name);
-		exit(1);
-	}
+	argv_array_clear(&argv);
+	argv_array_clear(&env);
 }
 
 static int similarity_index(struct diff_filepair *p)
@@ -3042,7 +3040,7 @@ 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)
@@ -3201,12 +3199,15 @@ void diff_setup(struct diff_options *options)
 	options->context = diff_context_default;
 	DIFF_OPT_SET(options, RENAME_EMPTY);
 
+	/* pathchange left =NULL by default */
 	options->change = diff_change;
 	options->add_remove = diff_addremove;
 	options->use_color = diff_use_color_default;
 	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) {
@@ -3219,6 +3220,9 @@ 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)
@@ -3314,6 +3318,8 @@ 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)
@@ -3343,14 +3349,11 @@ static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *va
 	if (c != '-')
 		return 0;
 	arg++;
-	eq = strchr(arg, '=');
-	if (eq)
-		len = eq - arg;
-	else
-		len = strlen(arg);
+	eq = strchrnul(arg, '=');
+	len = eq - arg;
 	if (!len || strncmp(arg, arg_long, len))
 		return 0;
-	if (eq) {
+	if (*eq) {
 		int n;
 		char *end;
 		if (!isdigit(*++eq))
@@ -3388,10 +3391,10 @@ 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;
 	}
@@ -3419,7 +3422,7 @@ 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);
@@ -3429,7 +3432,7 @@ 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);
@@ -3439,7 +3442,7 @@ 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);
@@ -3449,7 +3452,7 @@ 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);
@@ -3503,6 +3506,80 @@ static int parse_submodule_opt(struct diff_options *options, const char *value)
 	return 1;
 }
 
+static const char diff_status_letters[] = {
+	DIFF_STATUS_ADDED,
+	DIFF_STATUS_COPIED,
+	DIFF_STATUS_DELETED,
+	DIFF_STATUS_MODIFIED,
+	DIFF_STATUS_RENAMED,
+	DIFF_STATUS_TYPE_CHANGED,
+	DIFF_STATUS_UNKNOWN,
+	DIFF_STATUS_UNMERGED,
+	DIFF_STATUS_FILTER_AON,
+	DIFF_STATUS_FILTER_BROKEN,
+	'\0',
+};
+
+static unsigned int filter_bit['Z' + 1];
+
+static void prepare_filter_bits(void)
+{
+	int i;
+
+	if (!filter_bit[DIFF_STATUS_ADDED]) {
+		for (i = 0; diff_status_letters[i]; i++)
+			filter_bit[(int) diff_status_letters[i]] = (1 << i);
+	}
+}
+
+static unsigned filter_bit_tst(char status, const struct diff_options *opt)
+{
+	return opt->filter & filter_bit[(int) status];
+}
+
+static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
+{
+	int i, optch;
+
+	prepare_filter_bits();
+
+	/*
+	 * If there is a negation e.g. 'd' in the input, and we haven't
+	 * initialized the filter field with another --diff-filter, start
+	 * from full set of bits, except for AON.
+	 */
+	if (!opt->filter) {
+		for (i = 0; (optch = optarg[i]) != '\0'; i++) {
+			if (optch < 'a' || 'z' < optch)
+				continue;
+			opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
+			opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
+			break;
+		}
+	}
+
+	for (i = 0; (optch = optarg[i]) != '\0'; i++) {
+		unsigned int bit;
+		int negate;
+
+		if ('a' <= optch && optch <= 'z') {
+			negate = 1;
+			optch = toupper(optch);
+		} else {
+			negate = 0;
+		}
+
+		bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
+		if (!bit)
+			return optarg[i];
+		if (negate)
+			opt->filter &= ~bit;
+		else
+			opt->filter |= bit;
+	}
+	return 0;
+}
+
 static void enable_patch_output(int *fmt) {
 	*fmt &= ~DIFF_FORMAT_NO_OUTPUT;
 	*fmt |= DIFF_FORMAT_PATCH;
@@ -3529,15 +3606,15 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		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);
 	}
@@ -3554,17 +3631,17 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->output_format |= DIFF_FORMAT_NAME_STATUS;
 	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);
@@ -3573,7 +3650,7 @@ 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);
@@ -3589,7 +3666,7 @@ 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;
 	}
@@ -3642,7 +3719,7 @@ 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\"");
@@ -3654,7 +3731,7 @@ 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;
@@ -3663,7 +3740,7 @@ 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;
@@ -3699,12 +3776,12 @@ 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 */
@@ -3732,12 +3809,15 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		return argcount;
 	}
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
-		options->filter = optarg;
+		int offending = parse_diff_filter_opt(optarg, options);
+		if (offending)
+			die("unknown change class '%c' in --diff-filter=%s",
+			    offending, optarg);
 		return argcount;
 	}
 	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;
@@ -3819,22 +3899,22 @@ 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';
 		}
 	}
 	if (cmd != 'M' && cmd != 'C' && cmd != 'B')
-		return -1; /* that is not a -M, -C nor -B option */
+		return -1; /* that is not a -M, -C, or -B option */
 
 	opt1 = parse_rename_score(&opt);
 	if (cmd != 'B')
@@ -3858,11 +3938,7 @@ struct diff_queue_struct diff_queued_diff;
 
 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 {
-	if (queue->alloc <= queue->nr) {
-		queue->alloc = alloc_nr(queue->alloc);
-		queue->queue = xrealloc(queue->queue,
-					sizeof(dp) * queue->alloc);
-	}
+	ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
 	queue->queue[queue->nr++] = dp;
 }
 
@@ -4032,9 +4108,9 @@ 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)
@@ -4237,7 +4313,7 @@ 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);
@@ -4524,27 +4600,32 @@ free_queue:
 	}
 }
 
-static void diffcore_apply_filter(const char *filter)
+static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
+{
+	return (((p->status == DIFF_STATUS_MODIFIED) &&
+		 ((p->score &&
+		   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
+		  (!p->score &&
+		   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
+		((p->status != DIFF_STATUS_MODIFIED) &&
+		 filter_bit_tst(p->status, options)));
+}
+
+static void diffcore_apply_filter(struct diff_options *options)
 {
 	int i;
 	struct diff_queue_struct *q = &diff_queued_diff;
 	struct diff_queue_struct outq;
+
 	DIFF_QUEUE_CLEAR(&outq);
 
-	if (!filter)
+	if (!options->filter)
 		return;
 
-	if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
+	if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
 		int found;
 		for (i = found = 0; !found && i < q->nr; i++) {
-			struct diff_filepair *p = q->queue[i];
-			if (((p->status == DIFF_STATUS_MODIFIED) &&
-			     ((p->score &&
-			       strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
-			      (!p->score &&
-			       strchr(filter, DIFF_STATUS_MODIFIED)))) ||
-			    ((p->status != DIFF_STATUS_MODIFIED) &&
-			     strchr(filter, p->status)))
+			if (match_filter(options, q->queue[i]))
 				found++;
 		}
 		if (found)
@@ -4562,14 +4643,7 @@ static void diffcore_apply_filter(const char *filter)
 		/* Only the matching ones */
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
-
-			if (((p->status == DIFF_STATUS_MODIFIED) &&
-			     ((p->score &&
-			       strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
-			      (!p->score &&
-			       strchr(filter, DIFF_STATUS_MODIFIED)))) ||
-			    ((p->status != DIFF_STATUS_MODIFIED) &&
-			     strchr(filter, p->status)))
+			if (match_filter(options, p))
 				diff_q(&outq, p);
 			else
 				diff_free_filepair(p);
@@ -4592,6 +4666,38 @@ 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;
@@ -4602,27 +4708,7 @@ 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 {
 			/*
@@ -4658,6 +4744,7 @@ void diffcore_fix_diff_index(struct diff_options *options)
 
 void diffcore_std(struct diff_options *options)
 {
+	/* NOTE please keep the following in sync with diff_tree_combined() */
 	if (options->skip_stat_unmatch)
 		diffcore_skip_stat_unmatch(options);
 	if (!options->found_follow) {
@@ -4676,7 +4763,7 @@ void diffcore_std(struct diff_options *options)
 	if (!options->found_follow)
 		/* See try_to_follow_renames() in tree-diff.c */
 		diff_resolve_rename_copy();
-	diffcore_apply_filter(options->filter);
+	diffcore_apply_filter(options);
 
 	if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
 		DIFF_OPT_SET(options, HAS_CHANGES);
@@ -4785,6 +4872,7 @@ 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))
@@ -4811,10 +4899,16 @@ 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)