X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=diff.c;h=6a713764831e7521958f4b280f2e1d3911fb3cea;hb=f1efc38bf2856f875b878177c0f0a98d9eb3bb4e;hp=9e9cfc8b75b7b761980b0d32cb0c516ea3505ba3;hpb=31262627109476c529418132e0820687003fb1fe;p=git.git

diff --git a/diff.c b/diff.c
index 9e9cfc8b7..6a7137648 100644
--- a/diff.c
+++ b/diff.c
@@ -13,15 +13,197 @@
 
 static int use_size_cache;
 
-int diff_rename_limit_default = -1;
+static int diff_detect_rename_default = 0;
+static int diff_rename_limit_default = -1;
+static int diff_use_color_default = 0;
+
+/* "\033[1;38;5;2xx;48;5;2xxm\0" is 23 bytes */
+static char diff_colors[][24] = {
+	"\033[m",	/* reset */
+	"",		/* normal */
+	"\033[1m",	/* bold */
+	"\033[36m",	/* cyan */
+	"\033[31m",	/* red */
+	"\033[32m",	/* green */
+	"\033[33m"	/* yellow */
+};
+
+static int parse_diff_color_slot(const char *var, int ofs)
+{
+	if (!strcasecmp(var+ofs, "plain"))
+		return DIFF_PLAIN;
+	if (!strcasecmp(var+ofs, "meta"))
+		return DIFF_METAINFO;
+	if (!strcasecmp(var+ofs, "frag"))
+		return DIFF_FRAGINFO;
+	if (!strcasecmp(var+ofs, "old"))
+		return DIFF_FILE_OLD;
+	if (!strcasecmp(var+ofs, "new"))
+		return DIFF_FILE_NEW;
+	if (!strcasecmp(var+ofs, "commit"))
+		return DIFF_COMMIT;
+	die("bad config variable '%s'", var);
+}
+
+static int parse_color(const char *name, int len)
+{
+	static const char * const color_names[] = {
+		"normal", "black", "red", "green", "yellow",
+		"blue", "magenta", "cyan", "white"
+	};
+	char *end;
+	int i;
+	for (i = 0; i < ARRAY_SIZE(color_names); i++) {
+		const char *str = color_names[i];
+		if (!strncasecmp(name, str, len) && !str[len])
+			return i - 1;
+	}
+	i = strtol(name, &end, 10);
+	if (*name && !*end && i >= -1 && i <= 255)
+		return i;
+	return -2;
+}
+
+static int parse_attr(const char *name, int len)
+{
+	static const int attr_values[] = { 1, 2, 4, 5, 7 };
+	static const char * const attr_names[] = {
+		"bold", "dim", "ul", "blink", "reverse"
+	};
+	int i;
+	for (i = 0; i < ARRAY_SIZE(attr_names); i++) {
+		const char *str = attr_names[i];
+		if (!strncasecmp(name, str, len) && !str[len])
+			return attr_values[i];
+	}
+	return -1;
+}
+
+static void parse_diff_color_value(const char *value, const char *var, char *dst)
+{
+	const char *ptr = value;
+	int attr = -1;
+	int fg = -2;
+	int bg = -2;
+
+	if (!strcasecmp(value, "reset")) {
+		strcpy(dst, "\033[m");
+		return;
+	}
+
+	/* [fg [bg]] [attr] */
+	while (*ptr) {
+		const char *word = ptr;
+		int val, len = 0;
+
+		while (word[len] && !isspace(word[len]))
+			len++;
+
+		ptr = word + len;
+		while (*ptr && isspace(*ptr))
+			ptr++;
+
+		val = parse_color(word, len);
+		if (val >= -1) {
+			if (fg == -2) {
+				fg = val;
+				continue;
+			}
+			if (bg == -2) {
+				bg = val;
+				continue;
+			}
+			goto bad;
+		}
+		val = parse_attr(word, len);
+		if (val < 0 || attr != -1)
+			goto bad;
+		attr = val;
+	}
+
+	if (attr >= 0 || fg >= 0 || bg >= 0) {
+		int sep = 0;
+
+		*dst++ = '\033';
+		*dst++ = '[';
+		if (attr >= 0) {
+			*dst++ = '0' + attr;
+			sep++;
+		}
+		if (fg >= 0) {
+			if (sep++)
+				*dst++ = ';';
+			if (fg < 8) {
+				*dst++ = '3';
+				*dst++ = '0' + fg;
+			} else {
+				dst += sprintf(dst, "38;5;%d", fg);
+			}
+		}
+		if (bg >= 0) {
+			if (sep++)
+				*dst++ = ';';
+			if (bg < 8) {
+				*dst++ = '4';
+				*dst++ = '0' + bg;
+			} else {
+				dst += sprintf(dst, "48;5;%d", bg);
+			}
+		}
+		*dst++ = 'm';
+	}
+	*dst = 0;
+	return;
+bad:
+	die("bad config value '%s' for variable '%s'", value, var);
+}
 
-int git_diff_config(const char *var, const char *value)
+/*
+ * These are to give UI layer defaults.
+ * The core-level commands such as git-diff-files should
+ * never be affected by the setting of diff.renames
+ * the user happens to have in the configuration file.
+ */
+int git_diff_ui_config(const char *var, const char *value)
 {
 	if (!strcmp(var, "diff.renamelimit")) {
 		diff_rename_limit_default = git_config_int(var, value);
 		return 0;
 	}
-
+	if (!strcmp(var, "diff.color")) {
+		if (!value)
+			diff_use_color_default = 1; /* bool */
+		else if (!strcasecmp(value, "auto")) {
+			diff_use_color_default = 0;
+			if (isatty(1) || pager_in_use) {
+				char *term = getenv("TERM");
+				if (term && strcmp(term, "dumb"))
+					diff_use_color_default = 1;
+			}
+		}
+		else if (!strcasecmp(value, "never"))
+			diff_use_color_default = 0;
+		else if (!strcasecmp(value, "always"))
+			diff_use_color_default = 1;
+		else
+			diff_use_color_default = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "diff.renames")) {
+		if (!value)
+			diff_detect_rename_default = DIFF_DETECT_RENAME;
+		else if (!strcasecmp(value, "copies") ||
+			 !strcasecmp(value, "copy"))
+			diff_detect_rename_default = DIFF_DETECT_COPY;
+		else if (git_config_bool(var,value))
+			diff_detect_rename_default = DIFF_DETECT_RENAME;
+		return 0;
+	}
+	if (!strncmp(var, "diff.color.", 11)) {
+		int slot = parse_diff_color_slot(var, 11);
+		parse_diff_color_value(value, var, diff_colors[slot]);
+		return 0;
+	}
 	return git_default_config(var, value);
 }
 
@@ -165,7 +347,7 @@ static void emit_rewrite_diff(const char *name_a,
 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 {
 	if (!DIFF_FILE_VALID(one)) {
-		mf->ptr = ""; /* does not matter */
+		mf->ptr = (char *)""; /* does not matter */
 		mf->size = 0;
 		return 0;
 	}
@@ -177,23 +359,58 @@ static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 }
 
 struct emit_callback {
+	struct xdiff_emit_state xm;
+	int nparents, color_diff;
 	const char **label_path;
 };
 
-static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
+const char *diff_get_color(int diff_use_color, enum color_diff ix)
+{
+	if (diff_use_color)
+		return diff_colors[ix];
+	return "";
+}
+
+static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
 	int i;
 	struct emit_callback *ecbdata = priv;
+	const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
+	const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 
 	if (ecbdata->label_path[0]) {
-		printf("--- %s\n", ecbdata->label_path[0]);
-		printf("+++ %s\n", ecbdata->label_path[1]);
+		printf("%s--- %s%s\n", set, ecbdata->label_path[0], reset);
+		printf("%s+++ %s%s\n", set, ecbdata->label_path[1], reset);
 		ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 	}
-	for (i = 0; i < nbuf; i++)
-		if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
-			return -1;
-	return 0;
+
+	/* This is not really necessary for now because
+	 * this codepath only deals with two-way diffs.
+	 */
+	for (i = 0; i < len && line[i] == '@'; i++)
+		;
+	if (2 <= i && i < len && line[i] == ' ') {
+		ecbdata->nparents = i - 1;
+		set = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
+	}
+	else if (len < ecbdata->nparents)
+		set = reset;
+	else {
+		int nparents = ecbdata->nparents;
+		int color = DIFF_PLAIN;
+		for (i = 0; i < nparents && len; i++) {
+			if (line[i] == '-')
+				color = DIFF_FILE_OLD;
+			else if (line[i] == '+')
+				color = DIFF_FILE_NEW;
+		}
+		set = diff_get_color(ecbdata->color_diff, color);
+	}
+	if (len > 0 && line[len-1] == '\n')
+		len--;
+	fputs (set, stdout);
+	fwrite (line, len, 1, stdout);
+	puts (reset);
 }
 
 static char *pprint_rename(const char *a, const char *b)
@@ -324,7 +541,7 @@ static void show_stats(struct diffstat_t* data)
 	}
 
 	for (i = 0; i < data->nr; i++) {
-		char *prefix = "";
+		const char *prefix = "";
 		char *name = data->files[i]->name;
 		int added = data->files[i]->added;
 		int deleted = data->files[i]->deleted;
@@ -447,7 +664,7 @@ static unsigned char *deflate_it(char *data,
 	z_stream stream;
 
 	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
+	deflateInit(&stream, zlib_compression_level);
 	bound = deflateBound(&stream, size);
 	deflated = xmalloc(bound);
 	stream.next_out = deflated;
@@ -515,7 +732,7 @@ static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 		else
 			line[0] = bytes - 26 + 'a' - 1;
 		encode_85(line + 1, cp, bytes);
-		cp += bytes;
+		cp = (char *) cp + bytes;
 		puts(line);
 	}
 	printf("\n");
@@ -544,30 +761,32 @@ static void builtin_diff(const char *name_a,
 	mmfile_t mf1, mf2;
 	const char *lbl[2];
 	char *a_one, *b_two;
+	const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
+	const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
 
 	a_one = quote_two("a/", name_a);
 	b_two = quote_two("b/", name_b);
 	lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 	lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
-	printf("diff --git %s %s\n", a_one, b_two);
+	printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
 	if (lbl[0][0] == '/') {
 		/* /dev/null */
-		printf("new file mode %06o\n", two->mode);
+		printf("%snew file mode %06o%s\n", set, two->mode, reset);
 		if (xfrm_msg && xfrm_msg[0])
-			puts(xfrm_msg);
+			printf("%s%s%s\n", set, xfrm_msg, reset);
 	}
 	else if (lbl[1][0] == '/') {
-		printf("deleted file mode %06o\n", one->mode);
+		printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
 		if (xfrm_msg && xfrm_msg[0])
-			puts(xfrm_msg);
+			printf("%s%s%s\n", set, xfrm_msg, reset);
 	}
 	else {
 		if (one->mode != two->mode) {
-			printf("old mode %06o\n", one->mode);
-			printf("new mode %06o\n", two->mode);
+			printf("%sold mode %06o%s\n", set, one->mode, reset);
+			printf("%snew mode %06o%s\n", set, two->mode, reset);
 		}
 		if (xfrm_msg && xfrm_msg[0])
-			puts(xfrm_msg);
+			printf("%s%s%s\n", set, xfrm_msg, reset);
 		/*
 		 * we do not run diff between different kind
 		 * of objects.
@@ -583,7 +802,7 @@ static void builtin_diff(const char *name_a,
 	if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 		die("unable to read files to diff");
 
-	if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
+	if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
 		/* Quite common confusing case */
 		if (mf1.size == mf2.size &&
 		    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
@@ -602,8 +821,10 @@ static void builtin_diff(const char *name_a,
 		xdemitcb_t ecb;
 		struct emit_callback ecbdata;
 
+		memset(&ecbdata, 0, sizeof(ecbdata));
 		ecbdata.label_path = lbl;
-		xpp.flags = XDF_NEED_MINIMAL;
+		ecbdata.color_diff = o->color_diff;
+		xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 		xecfg.ctxlen = o->context;
 		xecfg.flags = XDL_EMIT_FUNCNAMES;
 		if (!diffopts)
@@ -612,8 +833,9 @@ static void builtin_diff(const char *name_a,
 			xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 		else if (!strncmp(diffopts, "-u", 2))
 			xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
-		ecb.outf = fn_out;
+		ecb.outf = xdiff_outf;
 		ecb.priv = &ecbdata;
+		ecbdata.xm.consume = fn_out_consume;
 		xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 	}
 
@@ -627,6 +849,7 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 			     struct diff_filespec *one,
 			     struct diff_filespec *two,
 			     struct diffstat_t *diffstat,
+			     struct diff_options *o,
 			     int complete_rewrite)
 {
 	mmfile_t mf1, mf2;
@@ -656,7 +879,7 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 		xdemitconf_t xecfg;
 		xdemitcb_t ecb;
 
-		xpp.flags = XDF_NEED_MINIMAL;
+		xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 		xecfg.ctxlen = 0;
 		xecfg.flags = 0;
 		ecb.outf = xdiff_outf;
@@ -841,7 +1064,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 			err_empty:
 				err = -1;
 			empty:
-				s->data = "";
+				s->data = (char *)"";
 				s->size = 0;
 				return err;
 			}
@@ -1241,7 +1464,7 @@ static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
 
 	if (DIFF_PAIR_UNMERGED(p)) {
 		/* unmerged */
-		builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
+		builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
 		return;
 	}
 
@@ -1253,7 +1476,7 @@ static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
 
 	if (p->status == DIFF_STATUS_MODIFIED && p->score)
 		complete_rewrite = 1;
-	builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
+	builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
 }
 
 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
@@ -1278,14 +1501,16 @@ static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
 void diff_setup(struct diff_options *options)
 {
 	memset(options, 0, sizeof(*options));
-	options->output_format = DIFF_FORMAT_RAW;
 	options->line_termination = '\n';
 	options->break_opt = -1;
 	options->rename_limit = -1;
 	options->context = 3;
+	options->msg_sep = "";
 
 	options->change = diff_change;
 	options->add_remove = diff_addremove;
+	options->color_diff = diff_use_color_default;
+	options->detect_rename = diff_detect_rename_default;
 }
 
 int diff_setup_done(struct diff_options *options)
@@ -1295,22 +1520,28 @@ int diff_setup_done(struct diff_options *options)
 	    (0 <= options->rename_limit && !options->detect_rename))
 		return -1;
 
+	if (options->output_format & (DIFF_FORMAT_NAME |
+				      DIFF_FORMAT_NAME_STATUS |
+				      DIFF_FORMAT_CHECKDIFF |
+				      DIFF_FORMAT_NO_OUTPUT))
+		options->output_format &= ~(DIFF_FORMAT_RAW |
+					    DIFF_FORMAT_DIFFSTAT |
+					    DIFF_FORMAT_SUMMARY |
+					    DIFF_FORMAT_PATCH);
+
 	/*
 	 * These cases always need recursive; we do not drop caller-supplied
 	 * recursive bits for other formats here.
 	 */
-	if ((options->output_format == DIFF_FORMAT_PATCH) ||
-	    (options->output_format == DIFF_FORMAT_DIFFSTAT) ||
-	    (options->output_format == DIFF_FORMAT_CHECKDIFF))
+	if (options->output_format & (DIFF_FORMAT_PATCH |
+				      DIFF_FORMAT_DIFFSTAT |
+				      DIFF_FORMAT_CHECKDIFF))
 		options->recursive = 1;
-
 	/*
-	 * These combinations do not make sense.
+	 * Also pickaxe would not work very well if you do not say recursive
 	 */
-	if (options->output_format == DIFF_FORMAT_RAW)
-		options->with_raw = 0;
-	if (options->output_format == DIFF_FORMAT_DIFFSTAT)
-		options->with_stat  = 0;
+	if (options->pickaxe)
+		options->recursive = 1;
 
 	if (options->detect_rename && options->rename_limit < 0)
 		options->rename_limit = diff_rename_limit_default;
@@ -1332,7 +1563,7 @@ int diff_setup_done(struct diff_options *options)
 	return 0;
 }
 
-int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
+static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
 {
 	char c, *eq;
 	int len;
@@ -1383,22 +1614,22 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
 	const char *arg = av[0];
 	if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
-		options->output_format = DIFF_FORMAT_PATCH;
+		options->output_format |= DIFF_FORMAT_PATCH;
 	else if (opt_arg(arg, 'U', "unified", &options->context))
-		options->output_format = DIFF_FORMAT_PATCH;
+		options->output_format |= DIFF_FORMAT_PATCH;
+	else if (!strcmp(arg, "--raw"))
+		options->output_format |= DIFF_FORMAT_RAW;
 	else if (!strcmp(arg, "--patch-with-raw")) {
-		options->output_format = DIFF_FORMAT_PATCH;
-		options->with_raw = 1;
+		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
 	}
 	else if (!strcmp(arg, "--stat"))
-		options->output_format = DIFF_FORMAT_DIFFSTAT;
+		options->output_format |= DIFF_FORMAT_DIFFSTAT;
 	else if (!strcmp(arg, "--check"))
-		options->output_format = DIFF_FORMAT_CHECKDIFF;
+		options->output_format |= DIFF_FORMAT_CHECKDIFF;
 	else if (!strcmp(arg, "--summary"))
-		options->summary = 1;
+		options->output_format |= DIFF_FORMAT_SUMMARY;
 	else if (!strcmp(arg, "--patch-with-stat")) {
-		options->output_format = DIFF_FORMAT_PATCH;
-		options->with_stat = 1;
+		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
 	}
 	else if (!strcmp(arg, "-z"))
 		options->line_termination = 0;
@@ -1407,19 +1638,23 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--full-index"))
 		options->full_index = 1;
 	else if (!strcmp(arg, "--binary")) {
-		options->output_format = DIFF_FORMAT_PATCH;
+		options->output_format |= DIFF_FORMAT_PATCH;
 		options->full_index = options->binary = 1;
 	}
+	else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
+		options->text = 1;
+	}
 	else if (!strcmp(arg, "--name-only"))
-		options->output_format = DIFF_FORMAT_NAME;
+		options->output_format |= DIFF_FORMAT_NAME;
 	else if (!strcmp(arg, "--name-status"))
-		options->output_format = DIFF_FORMAT_NAME_STATUS;
+		options->output_format |= DIFF_FORMAT_NAME_STATUS;
 	else if (!strcmp(arg, "-R"))
 		options->reverse_diff = 1;
 	else if (!strncmp(arg, "-S", 2))
 		options->pickaxe = arg + 2;
-	else if (!strcmp(arg, "-s"))
-		options->output_format = DIFF_FORMAT_NO_OUTPUT;
+	else if (!strcmp(arg, "-s")) {
+		options->output_format |= DIFF_FORMAT_NO_OUTPUT;
+	}
 	else if (!strncmp(arg, "-O", 2))
 		options->orderfile = arg + 2;
 	else if (!strncmp(arg, "--diff-filter=", 14))
@@ -1456,6 +1691,16 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		else if (40 < options->abbrev)
 			options->abbrev = 40;
 	}
+	else if (!strcmp(arg, "--color"))
+		options->color_diff = 1;
+	else if (!strcmp(arg, "--no-color"))
+		options->color_diff = 0;
+	else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
+		options->xdl_opts |= XDF_IGNORE_WHITESPACE;
+	else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
+		options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
+	else if (!strcmp(arg, "--no-renames"))
+		options->detect_rename = 0;
 	else
 		return 0;
 	return 1;
@@ -1588,15 +1833,17 @@ const char *diff_unique_abbrev(const unsigned char *sha1, int len)
 }
 
 static void diff_flush_raw(struct diff_filepair *p,
-			   int line_termination,
-			   int inter_name_termination,
-			   struct diff_options *options,
-			   int output_format)
+			   struct diff_options *options)
 {
 	int two_paths;
 	char status[10];
 	int abbrev = options->abbrev;
 	const char *path_one, *path_two;
+	int inter_name_termination = '\t';
+	int line_termination = options->line_termination;
+
+	if (!line_termination)
+		inter_name_termination = 0;
 
 	path_one = p->one->path;
 	path_two = p->two->path;
@@ -1625,7 +1872,7 @@ static void diff_flush_raw(struct diff_filepair *p,
 		two_paths = 0;
 		break;
 	}
-	if (output_format != DIFF_FORMAT_NAME_STATUS) {
+	if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
 		printf(":%06o %06o %s ",
 		       p->one->mode, p->two->mode,
 		       diff_unique_abbrev(p->one->sha1, abbrev));
@@ -1642,16 +1889,12 @@ static void diff_flush_raw(struct diff_filepair *p,
 		free((void*)path_two);
 }
 
-static void diff_flush_name(struct diff_filepair *p,
-			    int inter_name_termination,
-			    int line_termination)
+static void diff_flush_name(struct diff_filepair *p, int line_termination)
 {
 	char *path = p->two->path;
 
 	if (line_termination)
 		path = quote_one(p->two->path);
-	else
-		path = p->two->path;
 	printf("%s%c", path, line_termination);
 	if (p->two->path != path)
 		free(path);
@@ -1838,50 +2081,30 @@ static void diff_resolve_rename_copy(void)
 	diff_debug_queue("resolve-rename-copy done", q);
 }
 
-static void flush_one_pair(struct diff_filepair *p,
-			   int diff_output_format,
-			   struct diff_options *options,
-			   struct diffstat_t *diffstat)
+static int check_pair_status(struct diff_filepair *p)
 {
-	int inter_name_termination = '\t';
-	int line_termination = options->line_termination;
-	if (!line_termination)
-		inter_name_termination = 0;
-
 	switch (p->status) {
 	case DIFF_STATUS_UNKNOWN:
-		break;
+		return 0;
 	case 0:
 		die("internal error in diff-resolve-rename-copy");
-		break;
 	default:
-		switch (diff_output_format) {
-		case DIFF_FORMAT_DIFFSTAT:
-			diff_flush_stat(p, options, diffstat);
-			break;
-		case DIFF_FORMAT_CHECKDIFF:
-			diff_flush_checkdiff(p, options);
-			break;
-		case DIFF_FORMAT_PATCH:
-			diff_flush_patch(p, options);
-			break;
-		case DIFF_FORMAT_RAW:
-		case DIFF_FORMAT_NAME_STATUS:
-			diff_flush_raw(p, line_termination,
-				       inter_name_termination,
-				       options, diff_output_format);
-			break;
-		case DIFF_FORMAT_NAME:
-			diff_flush_name(p,
-					inter_name_termination,
-					line_termination);
-			break;
-		case DIFF_FORMAT_NO_OUTPUT:
-			break;
-		}
+		return 1;
 	}
 }
 
+static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
+{
+	int fmt = opt->output_format;
+
+	if (fmt & DIFF_FORMAT_CHECKDIFF)
+		diff_flush_checkdiff(p, opt);
+	else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
+		diff_flush_raw(p, opt);
+	else if (fmt & DIFF_FORMAT_NAME)
+		diff_flush_name(p, opt->line_termination);
+}
+
 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
 {
 	if (fs->mode)
@@ -1961,58 +2184,235 @@ static void diff_summary(struct diff_filepair *p)
 	}
 }
 
-void diff_flush(struct diff_options *options)
+struct patch_id_t {
+	struct xdiff_emit_state xm;
+	SHA_CTX *ctx;
+	int patchlen;
+};
+
+static int remove_space(char *line, int len)
+{
+	int i;
+        char *dst = line;
+        unsigned char c;
+
+        for (i = 0; i < len; i++)
+                if (!isspace((c = line[i])))
+                        *dst++ = c;
+
+        return dst - line;
+}
+
+static void patch_id_consume(void *priv, char *line, unsigned long len)
+{
+	struct patch_id_t *data = priv;
+	int new_len;
+
+	/* Ignore line numbers when computing the SHA1 of the patch */
+	if (!strncmp(line, "@@ -", 4))
+		return;
+
+	new_len = remove_space(line, len);
+
+	SHA1_Update(data->ctx, line, new_len);
+	data->patchlen += new_len;
+}
+
+/* returns 0 upon success, and writes result into sha1 */
+static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
+{
+	struct diff_queue_struct *q = &diff_queued_diff;
+	int i;
+	SHA_CTX ctx;
+	struct patch_id_t data;
+	char buffer[PATH_MAX * 4 + 20];
+
+	SHA1_Init(&ctx);
+	memset(&data, 0, sizeof(struct patch_id_t));
+	data.ctx = &ctx;
+	data.xm.consume = patch_id_consume;
+
+	for (i = 0; i < q->nr; i++) {
+		xpparam_t xpp;
+		xdemitconf_t xecfg;
+		xdemitcb_t ecb;
+		mmfile_t mf1, mf2;
+		struct diff_filepair *p = q->queue[i];
+		int len1, len2;
+
+		if (p->status == 0)
+			return error("internal diff status error");
+		if (p->status == DIFF_STATUS_UNKNOWN)
+			continue;
+		if (diff_unmodified_pair(p))
+			continue;
+		if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
+		    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
+			continue;
+		if (DIFF_PAIR_UNMERGED(p))
+			continue;
+
+		diff_fill_sha1_info(p->one);
+		diff_fill_sha1_info(p->two);
+		if (fill_mmfile(&mf1, p->one) < 0 ||
+				fill_mmfile(&mf2, p->two) < 0)
+			return error("unable to read files to diff");
+
+		/* Maybe hash p->two? into the patch id? */
+		if (mmfile_is_binary(&mf2))
+			continue;
+
+		len1 = remove_space(p->one->path, strlen(p->one->path));
+		len2 = remove_space(p->two->path, strlen(p->two->path));
+		if (p->one->mode == 0)
+			len1 = snprintf(buffer, sizeof(buffer),
+					"diff--gita/%.*sb/%.*s"
+					"newfilemode%06o"
+					"---/dev/null"
+					"+++b/%.*s",
+					len1, p->one->path,
+					len2, p->two->path,
+					p->two->mode,
+					len2, p->two->path);
+		else if (p->two->mode == 0)
+			len1 = snprintf(buffer, sizeof(buffer),
+					"diff--gita/%.*sb/%.*s"
+					"deletedfilemode%06o"
+					"---a/%.*s"
+					"+++/dev/null",
+					len1, p->one->path,
+					len2, p->two->path,
+					p->one->mode,
+					len1, p->one->path);
+		else
+			len1 = snprintf(buffer, sizeof(buffer),
+					"diff--gita/%.*sb/%.*s"
+					"---a/%.*s"
+					"+++b/%.*s",
+					len1, p->one->path,
+					len2, p->two->path,
+					len1, p->one->path,
+					len2, p->two->path);
+		SHA1_Update(&ctx, buffer, len1);
+
+		xpp.flags = XDF_NEED_MINIMAL;
+		xecfg.ctxlen = 3;
+		xecfg.flags = XDL_EMIT_FUNCNAMES;
+		ecb.outf = xdiff_outf;
+		ecb.priv = &data;
+		xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+	}
+
+	SHA1_Final(sha1, &ctx);
+	return 0;
+}
+
+int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
-	int diff_output_format = options->output_format;
-	struct diffstat_t *diffstat = NULL;
+	int result = diff_get_patch_id(options, sha1);
+
+	for (i = 0; i < q->nr; i++)
+		diff_free_filepair(q->queue[i]);
+
+	free(q->queue);
+	q->queue = NULL;
+	q->nr = q->alloc = 0;
+
+	return result;
+}
+
+static int is_summary_empty(const struct diff_queue_struct *q)
+{
+	int i;
+
+	for (i = 0; i < q->nr; i++) {
+		const struct diff_filepair *p = q->queue[i];
 
-	if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
-		diffstat = xcalloc(sizeof (struct diffstat_t), 1);
-		diffstat->xm.consume = diffstat_consume;
+		switch (p->status) {
+		case DIFF_STATUS_DELETED:
+		case DIFF_STATUS_ADDED:
+		case DIFF_STATUS_COPIED:
+		case DIFF_STATUS_RENAMED:
+			return 0;
+		default:
+			if (p->score)
+				return 0;
+			if (p->one->mode && p->two->mode &&
+			    p->one->mode != p->two->mode)
+				return 0;
+			break;
+		}
 	}
+	return 1;
+}
+
+void diff_flush(struct diff_options *options)
+{
+	struct diff_queue_struct *q = &diff_queued_diff;
+	int i, output_format = options->output_format;
+	int separator = 0;
+
+	/*
+	 * Order: raw, stat, summary, patch
+	 * or:    name/name-status/checkdiff (other bits clear)
+	 */
+	if (!q->nr)
+		goto free_queue;
 
-	if (options->with_raw) {
+	if (output_format & (DIFF_FORMAT_RAW |
+			     DIFF_FORMAT_NAME |
+			     DIFF_FORMAT_NAME_STATUS |
+			     DIFF_FORMAT_CHECKDIFF)) {
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
-			flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
+			if (check_pair_status(p))
+				flush_one_pair(p, options);
 		}
-		putchar(options->line_termination);
+		separator++;
 	}
-	if (options->with_stat) {
+
+	if (output_format & DIFF_FORMAT_DIFFSTAT) {
+		struct diffstat_t diffstat;
+
+		memset(&diffstat, 0, sizeof(struct diffstat_t));
+		diffstat.xm.consume = diffstat_consume;
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
-			flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
-				       diffstat);
+			if (check_pair_status(p))
+				diff_flush_stat(p, options, &diffstat);
 		}
-		show_stats(diffstat);
-		free(diffstat);
-		diffstat = NULL;
-		if (options->summary)
-			for (i = 0; i < q->nr; i++)
-				diff_summary(q->queue[i]);
-		if (options->stat_sep)
-			fputs(options->stat_sep, stdout);
-		else
-			putchar(options->line_termination);
-	}
-	for (i = 0; i < q->nr; i++) {
-		struct diff_filepair *p = q->queue[i];
-		flush_one_pair(p, diff_output_format, options, diffstat);
+		show_stats(&diffstat);
+		separator++;
 	}
 
-	if (diffstat) {
-		show_stats(diffstat);
-		free(diffstat);
+	if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
+		for (i = 0; i < q->nr; i++)
+			diff_summary(q->queue[i]);
+		separator++;
 	}
 
-	for (i = 0; i < q->nr; i++) {
-		if (diffstat && options->summary)
-			diff_summary(q->queue[i]);
-		diff_free_filepair(q->queue[i]);
+	if (output_format & DIFF_FORMAT_PATCH) {
+		if (separator) {
+			if (options->stat_sep) {
+				/* attach patch instead of inline */
+				fputs(options->stat_sep, stdout);
+			} else {
+				putchar(options->line_termination);
+			}
+		}
+
+		for (i = 0; i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (check_pair_status(p))
+				diff_flush_patch(p, options);
+		}
 	}
 
+	for (i = 0; i < q->nr; i++)
+		diff_free_filepair(q->queue[i]);
+free_queue:
 	free(q->queue);
 	q->queue = NULL;
 	q->nr = q->alloc = 0;