[thirdparty/git.git] / range-diff.c

#include "cache.h"
#include "range-diff.h"
#include "string-list.h"
#include "run-command.h"
#include "argv-array.h"
#include "hashmap.h"
#include "xdiff-interface.h"
#include "linear-assignment.h"
#include "diffcore.h"
#include "commit.h"
#include "pretty.h"
#include "userdiff.h"

struct patch_util {
	/* For the search for an exact match */
	struct hashmap_entry e;
	const char *diff, *patch;

	int i, shown;
	int diffsize;
	size_t diff_offset;
	/* the index of the matching item in the other branch, or -1 */
	int matching;
	struct object_id oid;
};

/*
 * Reads the patches into a string list, with the `util` field being populated
 * as struct object_id (will need to be free()d).
 */
static int read_patches(const char *range, struct string_list *list)
{
	struct child_process cp = CHILD_PROCESS_INIT;
	FILE *in;
	struct strbuf buf = STRBUF_INIT, line = STRBUF_INIT;
	struct patch_util *util = NULL;
	int in_header = 1;

	argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
			"--reverse", "--date-order", "--decorate=no",
			/*
			 * Choose indicators that are not used anywhere
			 * else in diffs, but still look reasonable
			 * (e.g. will not be confusing when debugging)
			 */
			"--output-indicator-new=>",
			"--output-indicator-old=<",
			"--output-indicator-context=#",
			"--no-abbrev-commit", range,
			NULL);
	cp.out = -1;
	cp.no_stdin = 1;
	cp.git_cmd = 1;

	if (start_command(&cp))
		return error_errno(_("could not start `log`"));
	in = fdopen(cp.out, "r");
	if (!in) {
		error_errno(_("could not read `log` output"));
		finish_command(&cp);
		return -1;
	}

	while (strbuf_getline(&line, in) != EOF) {
		const char *p;

		if (skip_prefix(line.buf, "commit ", &p)) {
			if (util) {
				string_list_append(list, buf.buf)->util = util;
				strbuf_reset(&buf);
			}
			util = xcalloc(sizeof(*util), 1);
			if (get_oid(p, &util->oid)) {
				error(_("could not parse commit '%s'"), p);
				free(util);
				string_list_clear(list, 1);
				strbuf_release(&buf);
				strbuf_release(&line);
				fclose(in);
				finish_command(&cp);
				return -1;
			}
			util->matching = -1;
			in_header = 1;
			continue;
		}

		if (starts_with(line.buf, "diff --git")) {
			in_header = 0;
			strbuf_addch(&buf, '\n');
			if (!util->diff_offset)
				util->diff_offset = buf.len;
			strbuf_addch(&buf, ' ');
			strbuf_addbuf(&buf, &line);
		} else if (in_header) {
			if (starts_with(line.buf, "Author: ")) {
				strbuf_addbuf(&buf, &line);
				strbuf_addstr(&buf, "\n\n");
			} else if (starts_with(line.buf, "    ")) {
				strbuf_rtrim(&line);
				strbuf_addbuf(&buf, &line);
				strbuf_addch(&buf, '\n');
			}
			continue;
		} else if (starts_with(line.buf, "@@ "))
			strbuf_addstr(&buf, "@@");
		else if (!line.buf[0] || starts_with(line.buf, "index "))
			/*
			 * A completely blank (not ' \n', which is context)
			 * line is not valid in a diff.  We skip it
			 * silently, because this neatly handles the blank
			 * separator line between commits in git-log
			 * output.
			 *
			 * We also want to ignore the diff's `index` lines
			 * because they contain exact blob hashes in which
			 * we are not interested.
			 */
			continue;
		else if (line.buf[0] == '>') {
			strbuf_addch(&buf, '+');
			strbuf_add(&buf, line.buf + 1, line.len - 1);
		} else if (line.buf[0] == '<') {
			strbuf_addch(&buf, '-');
			strbuf_add(&buf, line.buf + 1, line.len - 1);
		} else if (line.buf[0] == '#') {
			strbuf_addch(&buf, ' ');
			strbuf_add(&buf, line.buf + 1, line.len - 1);
		} else {
			strbuf_addch(&buf, ' ');
			strbuf_addbuf(&buf, &line);
		}

		strbuf_addch(&buf, '\n');
		util->diffsize++;
	}
	fclose(in);
	strbuf_release(&line);

	if (util)
		string_list_append(list, buf.buf)->util = util;
	strbuf_release(&buf);

	if (finish_command(&cp))
		return -1;

	return 0;
}

static int patch_util_cmp(const void *dummy, const struct patch_util *a,
		     const struct patch_util *b, const char *keydata)
{
	return strcmp(a->diff, keydata ? keydata : b->diff);
}

static void find_exact_matches(struct string_list *a, struct string_list *b)
{
	struct hashmap map;
	int i;

	hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);

	/* First, add the patches of a to a hash map */
	for (i = 0; i < a->nr; i++) {
		struct patch_util *util = a->items[i].util;

		util->i = i;
		util->patch = a->items[i].string;
		util->diff = util->patch + util->diff_offset;
		hashmap_entry_init(util, strhash(util->diff));
		hashmap_add(&map, util);
	}

	/* Now try to find exact matches in b */
	for (i = 0; i < b->nr; i++) {
		struct patch_util *util = b->items[i].util, *other;

		util->i = i;
		util->patch = b->items[i].string;
		util->diff = util->patch + util->diff_offset;
		hashmap_entry_init(util, strhash(util->diff));
		other = hashmap_remove(&map, util, NULL);
		if (other) {
			if (other->matching >= 0)
				BUG("already assigned!");

			other->matching = i;
			util->matching = other->i;
		}
	}

	hashmap_free(&map, 0);
}

static void diffsize_consume(void *data, char *line, unsigned long len)
{
	(*(int *)data)++;
}

static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
			  const char *funcline, long funclen)
{
	diffsize_consume(data, NULL, 0);
}

static int diffsize(const char *a, const char *b)
{
	xpparam_t pp = { 0 };
	xdemitconf_t cfg = { 0 };
	mmfile_t mf1, mf2;
	int count = 0;

	mf1.ptr = (char *)a;
	mf1.size = strlen(a);
	mf2.ptr = (char *)b;
	mf2.size = strlen(b);

	cfg.ctxlen = 3;
	if (!xdi_diff_outf(&mf1, &mf2,
			   diffsize_hunk, diffsize_consume, &count,
			   &pp, &cfg))
		return count;

	error(_("failed to generate diff"));
	return COST_MAX;
}

static void get_correspondences(struct string_list *a, struct string_list *b,
				int creation_factor)
{
	int n = a->nr + b->nr;
	int *cost, c, *a2b, *b2a;
	int i, j;

	ALLOC_ARRAY(cost, st_mult(n, n));
	ALLOC_ARRAY(a2b, n);
	ALLOC_ARRAY(b2a, n);

	for (i = 0; i < a->nr; i++) {
		struct patch_util *a_util = a->items[i].util;

		for (j = 0; j < b->nr; j++) {
			struct patch_util *b_util = b->items[j].util;

			if (a_util->matching == j)
				c = 0;
			else if (a_util->matching < 0 && b_util->matching < 0)
				c = diffsize(a_util->diff, b_util->diff);
			else
				c = COST_MAX;
			cost[i + n * j] = c;
		}

		c = a_util->matching < 0 ?
			a_util->diffsize * creation_factor / 100 : COST_MAX;
		for (j = b->nr; j < n; j++)
			cost[i + n * j] = c;
	}

	for (j = 0; j < b->nr; j++) {
		struct patch_util *util = b->items[j].util;

		c = util->matching < 0 ?
			util->diffsize * creation_factor / 100 : COST_MAX;
		for (i = a->nr; i < n; i++)
			cost[i + n * j] = c;
	}

	for (i = a->nr; i < n; i++)
		for (j = b->nr; j < n; j++)
			cost[i + n * j] = 0;

	compute_assignment(n, n, cost, a2b, b2a);

	for (i = 0; i < a->nr; i++)
		if (a2b[i] >= 0 && a2b[i] < b->nr) {
			struct patch_util *a_util = a->items[i].util;
			struct patch_util *b_util = b->items[a2b[i]].util;

			a_util->matching = a2b[i];
			b_util->matching = i;
		}

	free(cost);
	free(a2b);
	free(b2a);
}

static void output_pair_header(struct diff_options *diffopt,
			       int patch_no_width,
			       struct strbuf *buf,
			       struct strbuf *dashes,
			       struct patch_util *a_util,
			       struct patch_util *b_util)
{
	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
	struct commit *commit;
	char status;
	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	const char *color;

	if (!dashes->len)
		strbuf_addchars(dashes, '-',
				strlen(find_unique_abbrev(oid,
							  DEFAULT_ABBREV)));

	if (!b_util) {
		color = color_old;
		status = '<';
	} else if (!a_util) {
		color = color_new;
		status = '>';
	} else if (strcmp(a_util->patch, b_util->patch)) {
		color = color_commit;
		status = '!';
	} else {
		color = color_commit;
		status = '=';
	}

	strbuf_reset(buf);
	strbuf_addstr(buf, status == '!' ? color_old : color);
	if (!a_util)
		strbuf_addf(buf, "%*s:  %s ", patch_no_width, "-", dashes->buf);
	else
		strbuf_addf(buf, "%*d:  %s ", patch_no_width, a_util->i + 1,
			    find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));

	if (status == '!')
		strbuf_addf(buf, "%s%s", color_reset, color);
	strbuf_addch(buf, status);
	if (status == '!')
		strbuf_addf(buf, "%s%s", color_reset, color_new);

	if (!b_util)
		strbuf_addf(buf, " %*s:  %s", patch_no_width, "-", dashes->buf);
	else
		strbuf_addf(buf, " %*d:  %s", patch_no_width, b_util->i + 1,
			    find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));

	commit = lookup_commit_reference(the_repository, oid);
	if (commit) {
		if (status == '!')
			strbuf_addf(buf, "%s%s", color_reset, color);

		strbuf_addch(buf, ' ');
		pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	}
	strbuf_addf(buf, "%s\n", color_reset);

	fwrite(buf->buf, buf->len, 1, diffopt->file);
}

static struct userdiff_driver no_func_name = {
	.funcname = { "$^", 0 }
};

static struct diff_filespec *get_filespec(const char *name, const char *p)
{
	struct diff_filespec *spec = alloc_filespec(name);

	fill_filespec(spec, &null_oid, 0, 0100644);
	spec->data = (char *)p;
	spec->size = strlen(p);
	spec->should_munmap = 0;
	spec->is_stdin = 1;
	spec->driver = &no_func_name;

	return spec;
}

static void patch_diff(const char *a, const char *b,
			      struct diff_options *diffopt)
{
	diff_queue(&diff_queued_diff,
		   get_filespec("a", a), get_filespec("b", b));

	diffcore_std(diffopt);
	diff_flush(diffopt);
}

static void output(struct string_list *a, struct string_list *b,
		   struct diff_options *diffopt)
{
	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
	int i = 0, j = 0;

	/*
	 * We assume the user is really more interested in the second argument
	 * ("newer" version). To that end, we print the output in the order of
	 * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	 * commits that are no longer in the RHS into a good place, we place
	 * them once we have shown all of their predecessors in the LHS.
	 */

	while (i < a->nr || j < b->nr) {
		struct patch_util *a_util, *b_util;
		a_util = i < a->nr ? a->items[i].util : NULL;
		b_util = j < b->nr ? b->items[j].util : NULL;

		/* Skip all the already-shown commits from the LHS. */
		while (i < a->nr && a_util->shown)
			a_util = ++i < a->nr ? a->items[i].util : NULL;

		/* Show unmatched LHS commit whose predecessors were shown. */
		if (i < a->nr && a_util->matching < 0) {
			output_pair_header(diffopt, patch_no_width,
					   &buf, &dashes, a_util, NULL);
			i++;
			continue;
		}

		/* Show unmatched RHS commits. */
		while (j < b->nr && b_util->matching < 0) {
			output_pair_header(diffopt, patch_no_width,
					   &buf, &dashes, NULL, b_util);
			b_util = ++j < b->nr ? b->items[j].util : NULL;
		}

		/* Show matching LHS/RHS pair. */
		if (j < b->nr) {
			a_util = a->items[b_util->matching].util;
			output_pair_header(diffopt, patch_no_width,
					   &buf, &dashes, a_util, b_util);
			if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
				patch_diff(a->items[b_util->matching].string,
					   b->items[j].string, diffopt);
			a_util->shown = 1;
			j++;
		}
	}
	strbuf_release(&buf);
	strbuf_release(&dashes);
}

static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
{
	return data;
}

int show_range_diff(const char *range1, const char *range2,
		    int creation_factor, int dual_color,
		    struct diff_options *diffopt)
{
	int res = 0;

	struct string_list branch1 = STRING_LIST_INIT_DUP;
	struct string_list branch2 = STRING_LIST_INIT_DUP;

	if (read_patches(range1, &branch1))
		res = error(_("could not parse log for '%s'"), range1);
	if (!res && read_patches(range2, &branch2))
		res = error(_("could not parse log for '%s'"), range2);

	if (!res) {
		struct diff_options opts;
		struct strbuf indent = STRBUF_INIT;

		if (diffopt)
			memcpy(&opts, diffopt, sizeof(opts));
		else
			diff_setup(&opts);

		if (!opts.output_format)
			opts.output_format = DIFF_FORMAT_PATCH;
		opts.flags.suppress_diff_headers = 1;
		opts.flags.dual_color_diffed_diffs = dual_color;
		opts.output_prefix = output_prefix_cb;
		strbuf_addstr(&indent, "    ");
		opts.output_prefix_data = &indent;
		diff_setup_done(&opts);

		find_exact_matches(&branch1, &branch2);
		get_correspondences(&branch1, &branch2, creation_factor);
		output(&branch1, &branch2, &opts);

		strbuf_release(&indent);
	}

	string_list_clear(&branch1, 1);
	string_list_clear(&branch2, 1);

	return res;
}
Commit	Line	Data
d9c66f0b JS	1	#include "cache.h"
	2	#include "range-diff.h"
	3	#include "string-list.h"
	4	#include "run-command.h"
	5	#include "argv-array.h"
	6	#include "hashmap.h"
	7	#include "xdiff-interface.h"
	8	#include "linear-assignment.h"
c8c5e43a	9	#include "diffcore.h"
eb0be38c JS	10	#include "commit.h"
eb0be38c JS	11	#include "pretty.h"
4eba1fe6	12	#include "userdiff.h"
d9c66f0b JS	13
	14	struct patch_util {
	15	/* For the search for an exact match */
	16	struct hashmap_entry e;
	17	const char diff, patch;
	18
9dc46e02	19	int i, shown;
d9c66f0b JS	20	int diffsize;
	21	size_t diff_offset;
	22	/* the index of the matching item in the other branch, or -1 */
	23	int matching;
	24	struct object_id oid;
	25	};
	26
	27	/*
	28	* Reads the patches into a string list, with the `util` field being populated
	29	* as struct object_id (will need to be free()d).
	30	*/
	31	static int read_patches(const char range, struct string_list list)
	32	{
	33	struct child_process cp = CHILD_PROCESS_INIT;
	34	FILE *in;
	35	struct strbuf buf = STRBUF_INIT, line = STRBUF_INIT;
	36	struct patch_util *util = NULL;
	37	int in_header = 1;
	38
	39	argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
	40	"--reverse", "--date-order", "--decorate=no",
8d5ccb59 SB	41	/*
	42	* Choose indicators that are not used anywhere
	43	* else in diffs, but still look reasonable
	44	* (e.g. will not be confusing when debugging)
	45	*/
	46	"--output-indicator-new=>",
	47	"--output-indicator-old=<",
	48	"--output-indicator-context=#",
d9c66f0b JS	49	"--no-abbrev-commit", range,
	50	NULL);
	51	cp.out = -1;
	52	cp.no_stdin = 1;
	53	cp.git_cmd = 1;
	54
	55	if (start_command(&cp))
	56	return error_errno(_("could not start `log`"));
	57	in = fdopen(cp.out, "r");
	58	if (!in) {
	59	error_errno(_("could not read `log` output"));
	60	finish_command(&cp);
	61	return -1;
	62	}
	63
	64	while (strbuf_getline(&line, in) != EOF) {
	65	const char *p;
	66
	67	if (skip_prefix(line.buf, "commit ", &p)) {
	68	if (util) {
	69	string_list_append(list, buf.buf)->util = util;
	70	strbuf_reset(&buf);
	71	}
	72	util = xcalloc(sizeof(*util), 1);
	73	if (get_oid(p, &util->oid)) {
	74	error(_("could not parse commit '%s'"), p);
	75	free(util);
	76	string_list_clear(list, 1);
	77	strbuf_release(&buf);
	78	strbuf_release(&line);
	79	fclose(in);
	80	finish_command(&cp);
	81	return -1;
	82	}
	83	util->matching = -1;
	84	in_header = 1;
	85	continue;
	86	}
	87
	88	if (starts_with(line.buf, "diff --git")) {
	89	in_header = 0;
	90	strbuf_addch(&buf, '\n');
	91	if (!util->diff_offset)
	92	util->diff_offset = buf.len;
2543a641	93	strbuf_addch(&buf, ' ');
d9c66f0b JS	94	strbuf_addbuf(&buf, &line);
	95	} else if (in_header) {
	96	if (starts_with(line.buf, "Author: ")) {
	97	strbuf_addbuf(&buf, &line);
	98	strbuf_addstr(&buf, "\n\n");
	99	} else if (starts_with(line.buf, " ")) {
a142f978	100	strbuf_rtrim(&line);
d9c66f0b JS	101	strbuf_addbuf(&buf, &line);
	102	strbuf_addch(&buf, '\n');
	103	}
	104	continue;
	105	} else if (starts_with(line.buf, "@@ "))
	106	strbuf_addstr(&buf, "@@");
	107	else if (!line.buf[0] \|\| starts_with(line.buf, "index "))
	108	/*
	109	* A completely blank (not ' \n', which is context)
	110	* line is not valid in a diff. We skip it
	111	* silently, because this neatly handles the blank
	112	* separator line between commits in git-log
	113	* output.
	114	*
	115	* We also want to ignore the diff's `index` lines
	116	* because they contain exact blob hashes in which
	117	* we are not interested.
	118	*/
	119	continue;
8d5ccb59 SB	120	else if (line.buf[0] == '>') {
	121	strbuf_addch(&buf, '+');
	122	strbuf_add(&buf, line.buf + 1, line.len - 1);
	123	} else if (line.buf[0] == '<') {
	124	strbuf_addch(&buf, '-');
	125	strbuf_add(&buf, line.buf + 1, line.len - 1);
	126	} else if (line.buf[0] == '#') {
	127	strbuf_addch(&buf, ' ');
	128	strbuf_add(&buf, line.buf + 1, line.len - 1);
	129	} else {
2543a641	130	strbuf_addch(&buf, ' ');
d9c66f0b	131	strbuf_addbuf(&buf, &line);
8d5ccb59	132	}
d9c66f0b JS	133
	134	strbuf_addch(&buf, '\n');
	135	util->diffsize++;
	136	}
	137	fclose(in);
	138	strbuf_release(&line);
	139
	140	if (util)
	141	string_list_append(list, buf.buf)->util = util;
	142	strbuf_release(&buf);
	143
	144	if (finish_command(&cp))
	145	return -1;
	146
	147	return 0;
	148	}
	149
	150	static int patch_util_cmp(const void dummy, const struct patch_util a,
	151	const struct patch_util b, const char keydata)
	152	{
	153	return strcmp(a->diff, keydata ? keydata : b->diff);
	154	}
	155
	156	static void find_exact_matches(struct string_list a, struct string_list b)
	157	{
	158	struct hashmap map;
	159	int i;
	160
	161	hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
	162
	163	/* First, add the patches of a to a hash map */
	164	for (i = 0; i < a->nr; i++) {
	165	struct patch_util *util = a->items[i].util;
	166
	167	util->i = i;
	168	util->patch = a->items[i].string;
	169	util->diff = util->patch + util->diff_offset;
	170	hashmap_entry_init(util, strhash(util->diff));
	171	hashmap_add(&map, util);
	172	}
	173
	174	/* Now try to find exact matches in b */
	175	for (i = 0; i < b->nr; i++) {
	176	struct patch_util util = b->items[i].util, other;
	177
	178	util->i = i;
	179	util->patch = b->items[i].string;
	180	util->diff = util->patch + util->diff_offset;
	181	hashmap_entry_init(util, strhash(util->diff));
	182	other = hashmap_remove(&map, util, NULL);
	183	if (other) {
	184	if (other->matching >= 0)
	185	BUG("already assigned!");
	186
	187	other->matching = i;
	188	util->matching = other->i;
	189	}
	190	}
	191
	192	hashmap_free(&map, 0);
	193	}
	194
	195	static void diffsize_consume(void data, char line, unsigned long len)
	196	{
197	((int )data)++;
198	}
199
d2eb8093 JK	200	static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
	201	const char *funcline, long funclen)
	202	{
	203	diffsize_consume(data, NULL, 0);
	204	}
	205
d9c66f0b JS	206	static int diffsize(const char a, const char b)
	207	{
	208	xpparam_t pp = { 0 };
	209	xdemitconf_t cfg = { 0 };
	210	mmfile_t mf1, mf2;
	211	int count = 0;
	212
	213	mf1.ptr = (char *)a;
	214	mf1.size = strlen(a);
	215	mf2.ptr = (char *)b;
	216	mf2.size = strlen(b);
	217
	218	cfg.ctxlen = 3;
d2eb8093 JK	219	if (!xdi_diff_outf(&mf1, &mf2,
	220	diffsize_hunk, diffsize_consume, &count,
	221	&pp, &cfg))
d9c66f0b JS	222	return count;
	223
	224	error(_("failed to generate diff"));
	225	return COST_MAX;
	226	}
	227
	228	static void get_correspondences(struct string_list a, struct string_list b,
	229	int creation_factor)
	230	{
	231	int n = a->nr + b->nr;
	232	int cost, c, a2b, *b2a;
	233	int i, j;
	234
	235	ALLOC_ARRAY(cost, st_mult(n, n));
	236	ALLOC_ARRAY(a2b, n);
	237	ALLOC_ARRAY(b2a, n);
	238
	239	for (i = 0; i < a->nr; i++) {
	240	struct patch_util *a_util = a->items[i].util;
	241
	242	for (j = 0; j < b->nr; j++) {
	243	struct patch_util *b_util = b->items[j].util;
	244
	245	if (a_util->matching == j)
	246	c = 0;
	247	else if (a_util->matching < 0 && b_util->matching < 0)
	248	c = diffsize(a_util->diff, b_util->diff);
	249	else
	250	c = COST_MAX;
	251	cost[i + n * j] = c;
	252	}
	253
	254	c = a_util->matching < 0 ?
	255	a_util->diffsize * creation_factor / 100 : COST_MAX;
	256	for (j = b->nr; j < n; j++)
	257	cost[i + n * j] = c;
	258	}
	259
	260	for (j = 0; j < b->nr; j++) {
	261	struct patch_util *util = b->items[j].util;
	262
	263	c = util->matching < 0 ?
	264	util->diffsize * creation_factor / 100 : COST_MAX;
	265	for (i = a->nr; i < n; i++)
	266	cost[i + n * j] = c;
	267	}
	268
	269	for (i = a->nr; i < n; i++)
	270	for (j = b->nr; j < n; j++)
	271	cost[i + n * j] = 0;
	272
	273	compute_assignment(n, n, cost, a2b, b2a);
	274
	275	for (i = 0; i < a->nr; i++)
	276	if (a2b[i] >= 0 && a2b[i] < b->nr) {
	277	struct patch_util *a_util = a->items[i].util;
	278	struct patch_util *b_util = b->items[a2b[i]].util;
	279
	280	a_util->matching = a2b[i];
	281	b_util->matching = i;
	282	}
	283
	284	free(cost);
	285	free(a2b);
286	free(b2a);
287	}
288
faa1df86	289	static void output_pair_header(struct diff_options *diffopt,
d1f87a2d	290	int patch_no_width,
faa1df86	291	struct strbuf *buf,
eb0be38c JS	292	struct strbuf *dashes,
	293	struct patch_util *a_util,
	294	struct patch_util *b_util)
d9c66f0b	295	{
eb0be38c JS	296	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
eb0be38c JS	297	struct commit *commit;
faa1df86 JS	298	char status;
	299	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	300	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	301	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	302	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	303	const char *color;
eb0be38c JS	304
	305	if (!dashes->len)
	306	strbuf_addchars(dashes, '-',
	307	strlen(find_unique_abbrev(oid,
	308	DEFAULT_ABBREV)));
	309
faa1df86 JS	310	if (!b_util) {
	311	color = color_old;
	312	status = '<';
	313	} else if (!a_util) {
	314	color = color_new;
	315	status = '>';
	316	} else if (strcmp(a_util->patch, b_util->patch)) {
	317	color = color_commit;
	318	status = '!';
	319	} else {
	320	color = color_commit;
	321	status = '=';
	322	}
	323
eb0be38c	324	strbuf_reset(buf);
faa1df86	325	strbuf_addstr(buf, status == '!' ? color_old : color);
eb0be38c	326	if (!a_util)
d1f87a2d	327	strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
eb0be38c	328	else
d1f87a2d	329	strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
eb0be38c JS	330	find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
eb0be38c JS	331
faa1df86 JS	332	if (status == '!')
	333	strbuf_addf(buf, "%s%s", color_reset, color);
	334	strbuf_addch(buf, status);
	335	if (status == '!')
	336	strbuf_addf(buf, "%s%s", color_reset, color_new);
eb0be38c JS	337
eb0be38c JS	338	if (!b_util)
d1f87a2d	339	strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
eb0be38c	340	else
d1f87a2d	341	strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
eb0be38c JS	342	find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
	343
	344	commit = lookup_commit_reference(the_repository, oid);
	345	if (commit) {
faa1df86 JS	346	if (status == '!')
	347	strbuf_addf(buf, "%s%s", color_reset, color);
	348
eb0be38c JS	349	strbuf_addch(buf, ' ');
	350	pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	351	}
faa1df86	352	strbuf_addf(buf, "%s\n", color_reset);
eb0be38c	353
87f1b2d4	354	fwrite(buf->buf, buf->len, 1, diffopt->file);
d9c66f0b JS	355	}
d9c66f0b JS	356
4eba1fe6 JS	357	static struct userdiff_driver no_func_name = {
	358	.funcname = { "$^", 0 }
	359	};
	360
c8c5e43a JS	361	static struct diff_filespec get_filespec(const char name, const char *p)
	362	{
	363	struct diff_filespec *spec = alloc_filespec(name);
	364
0e573e8f	365	fill_filespec(spec, &null_oid, 0, 0100644);
c8c5e43a JS	366	spec->data = (char *)p;
	367	spec->size = strlen(p);
	368	spec->should_munmap = 0;
	369	spec->is_stdin = 1;
4eba1fe6	370	spec->driver = &no_func_name;
c8c5e43a JS	371
	372	return spec;
	373	}
	374
	375	static void patch_diff(const char a, const char b,
	376	struct diff_options *diffopt)
	377	{
	378	diff_queue(&diff_queued_diff,
	379	get_filespec("a", a), get_filespec("b", b));
	380
	381	diffcore_std(diffopt);
	382	diff_flush(diffopt);
	383	}
	384
	385	static void output(struct string_list a, struct string_list b,
	386	struct diff_options *diffopt)
d9c66f0b	387	{
eb0be38c	388	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
d1f87a2d	389	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
9dc46e02 JS	390	int i = 0, j = 0;
	391
	392	/*
	393	* We assume the user is really more interested in the second argument
	394	* ("newer" version). To that end, we print the output in the order of
	395	* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	396	* commits that are no longer in the RHS into a good place, we place
	397	* them once we have shown all of their predecessors in the LHS.
	398	*/
	399
	400	while (i < a->nr \|\| j < b->nr) {
	401	struct patch_util a_util, b_util;
	402	a_util = i < a->nr ? a->items[i].util : NULL;
	403	b_util = j < b->nr ? b->items[j].util : NULL;
	404
	405	/* Skip all the already-shown commits from the LHS. */
	406	while (i < a->nr && a_util->shown)
	407	a_util = ++i < a->nr ? a->items[i].util : NULL;
	408
	409	/* Show unmatched LHS commit whose predecessors were shown. */
	410	if (i < a->nr && a_util->matching < 0) {
d1f87a2d	411	output_pair_header(diffopt, patch_no_width,
faa1df86	412	&buf, &dashes, a_util, NULL);
9dc46e02 JS	413	i++;
	414	continue;
	415	}
d9c66f0b	416
9dc46e02 JS	417	/* Show unmatched RHS commits. */
9dc46e02 JS	418	while (j < b->nr && b_util->matching < 0) {
d1f87a2d	419	output_pair_header(diffopt, patch_no_width,
faa1df86	420	&buf, &dashes, NULL, b_util);
9dc46e02	421	b_util = ++j < b->nr ? b->items[j].util : NULL;
d9c66f0b	422	}
d9c66f0b	423
9dc46e02 JS	424	/* Show matching LHS/RHS pair. */
	425	if (j < b->nr) {
	426	a_util = a->items[b_util->matching].util;
d1f87a2d	427	output_pair_header(diffopt, patch_no_width,
faa1df86	428	&buf, &dashes, a_util, b_util);
c8c5e43a JS	429	if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
	430	patch_diff(a->items[b_util->matching].string,
	431	b->items[j].string, diffopt);
9dc46e02 JS	432	a_util->shown = 1;
	433	j++;
	434	}
d9c66f0b	435	}
eb0be38c JS	436	strbuf_release(&buf);
eb0be38c JS	437	strbuf_release(&dashes);
d9c66f0b JS	438	}
d9c66f0b JS	439
73a834e9 ES	440	static struct strbuf output_prefix_cb(struct diff_options opt, void *data)
	441	{
	442	return data;
	443	}
	444
d9c66f0b	445	int show_range_diff(const char range1, const char range2,
73a834e9 ES	446	int creation_factor, int dual_color,
73a834e9 ES	447	struct diff_options *diffopt)
d9c66f0b JS	448	{
	449	int res = 0;
	450
	451	struct string_list branch1 = STRING_LIST_INIT_DUP;
	452	struct string_list branch2 = STRING_LIST_INIT_DUP;
	453
	454	if (read_patches(range1, &branch1))
	455	res = error(_("could not parse log for '%s'"), range1);
	456	if (!res && read_patches(range2, &branch2))
	457	res = error(_("could not parse log for '%s'"), range2);
	458
	459	if (!res) {
73a834e9 ES	460	struct diff_options opts;
	461	struct strbuf indent = STRBUF_INIT;
	462
d8981c3f JH	463	if (diffopt)
	464	memcpy(&opts, diffopt, sizeof(opts));
	465	else
	466	diff_setup(&opts);
	467
a48e12ef ÆAB	468	if (!opts.output_format)
a48e12ef ÆAB	469	opts.output_format = DIFF_FORMAT_PATCH;
73a834e9 ES	470	opts.flags.suppress_diff_headers = 1;
	471	opts.flags.dual_color_diffed_diffs = dual_color;
	472	opts.output_prefix = output_prefix_cb;
	473	strbuf_addstr(&indent, " ");
	474	opts.output_prefix_data = &indent;
	475	diff_setup_done(&opts);
	476
d9c66f0b JS	477	find_exact_matches(&branch1, &branch2);
d9c66f0b JS	478	get_correspondences(&branch1, &branch2, creation_factor);
73a834e9 ES	479	output(&branch1, &branch2, &opts);
	480
	481	strbuf_release(&indent);
d9c66f0b JS	482	}
	483
	484	string_list_clear(&branch1, 1);
	485	string_list_clear(&branch2, 1);
	486
	487	return res;
	488	}