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

/*
 * Helper functions for tree diff generation
 */
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"

static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
{
	char *newbase = xmalloc(baselen + pathlen + 2);
	memcpy(newbase, base, baselen);
	memcpy(newbase + baselen, path, pathlen);
	memcpy(newbase + baselen + pathlen, "/", 2);
	return newbase;
}

static char *malloc_fullname(const char *base, int baselen, const char *path, int pathlen)
{
	char *fullname = xmalloc(baselen + pathlen + 1);
	memcpy(fullname, base, baselen);
	memcpy(fullname + baselen, path, pathlen);
	fullname[baselen + pathlen] = 0;
	return fullname;
}

static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base, int baselen);

static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;
	char *fullname;

	sha1 = tree_entry_extract(t1, &path1, &mode1);
	sha2 = tree_entry_extract(t2, &path2, &mode2);

	pathlen1 = tree_entry_len(path1, sha1);
	pathlen2 = tree_entry_len(path2, sha2);
	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
	if (cmp < 0) {
		show_entry(opt, "-", t1, base, baselen);
		return -1;
	}
	if (cmp > 0) {
		show_entry(opt, "+", t2, base, baselen);
		return 1;
	}
	if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
		return 0;

	/*
	 * If the filemode has changed to/from a directory from/to a regular
	 * file, we need to consider it a remove and an add.
	 */
	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
		show_entry(opt, "-", t1, base, baselen);
		show_entry(opt, "+", t2, base, baselen);
		return 0;
	}

	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
		int retval;
		char *newbase = malloc_base(base, baselen, path1, pathlen1);
		if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
			newbase[baselen + pathlen1] = 0;
			opt->change(opt, mode1, mode2,
				    sha1, sha2, newbase, 0, 0);
			newbase[baselen + pathlen1] = '/';
		}
		retval = diff_tree_sha1(sha1, sha2, newbase, opt);
		free(newbase);
		return retval;
	}

	fullname = malloc_fullname(base, baselen, path1, pathlen1);
	opt->change(opt, mode1, mode2, sha1, sha2, fullname, 0, 0);
	free(fullname);
	return 0;
}

/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
{
	int all_interesting = 0;
	while (desc->size) {
		int show;

		if (all_interesting)
			show = 1;
		else {
			show = tree_entry_interesting(&desc->entry, base, baselen, &opt->pathspec);
			if (show == 2)
				all_interesting = 1;
		}
		if (show < 0)
			break;
		if (show)
			show_entry(opt, prefix, desc, base, baselen);
		update_tree_entry(desc);
	}
}

/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base, int baselen)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
	int pathlen = tree_entry_len(path, sha1);

	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
		enum object_type type;
		char *newbase = malloc_base(base, baselen, path, pathlen);
		struct tree_desc inner;
		void *tree;
		unsigned long size;

		tree = read_sha1_file(sha1, &type, &size);
		if (!tree || type != OBJ_TREE)
			die("corrupt tree sha %s", sha1_to_hex(sha1));

		if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
			newbase[baselen + pathlen] = 0;
			opt->add_remove(opt, *prefix, mode, sha1, newbase, 0);
			newbase[baselen + pathlen] = '/';
		}

		init_tree_desc(&inner, tree, size);
		show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);

		free(tree);
		free(newbase);
	} else {
		char *fullname = malloc_fullname(base, baselen, path, pathlen);
		opt->add_remove(opt, prefix[0], mode, sha1, fullname, 0);
		free(fullname);
	}
}

static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt, int *all_interesting)
{
	while (t->size) {
		int show = tree_entry_interesting(&t->entry, base, baselen, &opt->pathspec);
		if (show == 2)
			*all_interesting = 1;
		if (!show) {
			update_tree_entry(t);
			continue;
		}
		/* Skip it all? */
		if (show < 0)
			t->size = 0;
		return;
	}
}

int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	int baselen = strlen(base);
	int all_t1_interesting = 0;
	int all_t2_interesting = 0;

	for (;;) {
		if (DIFF_OPT_TST(opt, QUICK) &&
		    DIFF_OPT_TST(opt, HAS_CHANGES))
			break;
		if (opt->pathspec.nr) {
			if (!all_t1_interesting)
				skip_uninteresting(t1, base, baselen, opt,
						   &all_t1_interesting);
			if (!all_t2_interesting)
				skip_uninteresting(t2, base, baselen, opt,
						   &all_t2_interesting);
		}
		if (!t1->size) {
			if (!t2->size)
				break;
			show_entry(opt, "+", t2, base, baselen);
			update_tree_entry(t2);
			continue;
		}
		if (!t2->size) {
			show_entry(opt, "-", t1, base, baselen);
			update_tree_entry(t1);
			continue;
		}
		switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
		case -1:
			update_tree_entry(t1);
			continue;
		case 0:
			update_tree_entry(t1);
			/* Fallthrough */
		case 1:
			update_tree_entry(t2);
			continue;
		}
		die("git diff-tree: internal error");
	}
	return 0;
}

/*
 * Does it look like the resulting diff might be due to a rename?
 *  - single entry
 *  - not a valid previous file
 */
static inline int diff_might_be_rename(void)
{
	return diff_queued_diff.nr == 1 &&
		!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
}

static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	struct diff_options diff_opts;
	struct diff_queue_struct *q = &diff_queued_diff;
	struct diff_filepair *choice;
	const char *paths[1];
	int i;

	/* Remove the file creation entry from the diff queue, and remember it */
	choice = q->queue[0];
	q->nr = 0;

	diff_setup(&diff_opts);
	DIFF_OPT_SET(&diff_opts, RECURSIVE);
	DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
	diff_opts.single_follow = opt->pathspec.raw[0];
	diff_opts.break_opt = opt->break_opt;
	paths[0] = NULL;
	diff_tree_setup_paths(paths, &diff_opts);
	if (diff_setup_done(&diff_opts) < 0)
		die("unable to set up diff options to follow renames");
	diff_tree(t1, t2, base, &diff_opts);
	diffcore_std(&diff_opts);
	diff_tree_release_paths(&diff_opts);

	/* Go through the new set of filepairing, and see if we find a more interesting one */
	opt->found_follow = 0;
	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];

		/*
		 * Found a source? Not only do we use that for the new
		 * diff_queued_diff, we will also use that as the path in
		 * the future!
		 */
		if ((p->status == 'R' || p->status == 'C') &&
		    !strcmp(p->two->path, opt->pathspec.raw[0])) {
			/* Switch the file-pairs around */
			q->queue[i] = choice;
			choice = p;

			/* Update the path we use from now on.. */
			diff_tree_release_paths(opt);
			opt->pathspec.raw[0] = xstrdup(p->one->path);
			diff_tree_setup_paths(opt->pathspec.raw, opt);

			/*
			 * The caller expects us to return a set of vanilla
			 * filepairs to let a later call to diffcore_std()
			 * it makes to sort the renames out (among other
			 * things), but we already have found renames
			 * ourselves; signal diffcore_std() not to muck with
			 * rename information.
			 */
			opt->found_follow = 1;
			break;
		}
	}

	/*
	 * Then, discard all the non-relevant file pairs...
	 */
	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];
		diff_free_filepair(p);
	}

	/*
	 * .. and re-instate the one we want (which might be either the
	 * original one, or the rename/copy we found)
	 */
	q->queue[0] = choice;
	q->nr = 1;
}

int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
{
	void *tree1, *tree2;
	struct tree_desc t1, t2;
	unsigned long size1, size2;
	int retval;

	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	init_tree_desc(&t1, tree1, size1);
	init_tree_desc(&t2, tree2, size2);
	retval = diff_tree(&t1, &t2, base, opt);
	if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
		init_tree_desc(&t1, tree1, size1);
		init_tree_desc(&t2, tree2, size2);
		try_to_follow_renames(&t1, &t2, base, opt);
	}
	free(tree1);
	free(tree2);
	return retval;
}

int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
{
	int retval;
	void *tree;
	unsigned long size;
	struct tree_desc empty, real;

	tree = read_object_with_reference(new, tree_type, &size, NULL);
	if (!tree)
		die("unable to read root tree (%s)", sha1_to_hex(new));
	init_tree_desc(&real, tree, size);

	init_tree_desc(&empty, "", 0);
	retval = diff_tree(&empty, &real, base, opt);
	free(tree);
	return retval;
}

void diff_tree_release_paths(struct diff_options *opt)
{
	free_pathspec(&opt->pathspec);
}

void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
	init_pathspec(&opt->pathspec, p);
}
Commit	Line	Data
ac1b3d12 LT	1	/*
	2	* Helper functions for tree diff generation
	3	*/
	4	#include "cache.h"
	5	#include "diff.h"
750f7b66	6	#include "diffcore.h"
8e440259	7	#include "tree.h"
ac1b3d12	8
304de2d2	9	static char malloc_base(const char base, int baselen, const char *path, int pathlen)
ac1b3d12	10	{
ac1b3d12 LT	11	char *newbase = xmalloc(baselen + pathlen + 2);
	12	memcpy(newbase, base, baselen);
	13	memcpy(newbase + baselen, path, pathlen);
	14	memcpy(newbase + baselen + pathlen, "/", 2);
	15	return newbase;
	16	}
	17
fd55a19e DP	18	static char malloc_fullname(const char base, int baselen, const char *path, int pathlen)
	19	{
	20	char *fullname = xmalloc(baselen + pathlen + 1);
	21	memcpy(fullname, base, baselen);
	22	memcpy(fullname + baselen, path, pathlen);
	23	fullname[baselen + pathlen] = 0;
	24	return fullname;
	25	}
	26
cf995ede	27	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
304de2d2	28	const char *base, int baselen);
ac1b3d12	29
304de2d2	30	static int compare_tree_entry(struct tree_desc t1, struct tree_desc t2, const char base, int baselen, struct diff_options opt)
ac1b3d12 LT	31	{
	32	unsigned mode1, mode2;
	33	const char path1, path2;
	34	const unsigned char sha1, sha2;
	35	int cmp, pathlen1, pathlen2;
fd55a19e	36	char *fullname;
ac1b3d12	37
50f9a858 LT	38	sha1 = tree_entry_extract(t1, &path1, &mode1);
50f9a858 LT	39	sha2 = tree_entry_extract(t2, &path2, &mode2);
ac1b3d12	40
304de2d2 LT	41	pathlen1 = tree_entry_len(path1, sha1);
304de2d2 LT	42	pathlen2 = tree_entry_len(path2, sha2);
ac1b3d12 LT	43	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
ac1b3d12 LT	44	if (cmp < 0) {
304de2d2	45	show_entry(opt, "-", t1, base, baselen);
ac1b3d12 LT	46	return -1;
	47	}
	48	if (cmp > 0) {
304de2d2	49	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	50	return 1;
ac1b3d12 LT	51	}
8f67f8ae	52	if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
ac1b3d12 LT	53	return 0;
	54
	55	/*
	56	* If the filemode has changed to/from a directory from/to a regular
	57	* file, we need to consider it a remove and an add.
	58	*/
	59	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
304de2d2 LT	60	show_entry(opt, "-", t1, base, baselen);
304de2d2 LT	61	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	62	return 0;
	63	}
	64
8f67f8ae	65	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
ac1b3d12	66	int retval;
304de2d2	67	char *newbase = malloc_base(base, baselen, path1, pathlen1);
fd55a19e DP	68	if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
fd55a19e DP	69	newbase[baselen + pathlen1] = 0;
ac1b3d12	70	opt->change(opt, mode1, mode2,
e3d42c47	71	sha1, sha2, newbase, 0, 0);
fd55a19e DP	72	newbase[baselen + pathlen1] = '/';
fd55a19e DP	73	}
ac1b3d12 LT	74	retval = diff_tree_sha1(sha1, sha2, newbase, opt);
	75	free(newbase);
	76	return retval;
	77	}
	78
fd55a19e	79	fullname = malloc_fullname(base, baselen, path1, pathlen1);
e3d42c47	80	opt->change(opt, mode1, mode2, sha1, sha2, fullname, 0, 0);
fd55a19e	81	free(fullname);
ac1b3d12 LT	82	return 0;
	83	}
	84
ac1b3d12	85	/* A whole sub-tree went away or appeared */
304de2d2	86	static void show_tree(struct diff_options opt, const char prefix, struct tree_desc desc, const char base, int baselen)
ac1b3d12	87	{
1d848f64	88	int all_interesting = 0;
ac1b3d12	89	while (desc->size) {
1d848f64 JH	90	int show;
	91
	92	if (all_interesting)
	93	show = 1;
	94	else {
475005a1	95	show = tree_entry_interesting(&desc->entry, base, baselen, &opt->pathspec);
1d848f64 JH	96	if (show == 2)
	97	all_interesting = 1;
	98	}
5d865017 LT	99	if (show < 0)
	100	break;
	101	if (show)
304de2d2	102	show_entry(opt, prefix, desc, base, baselen);
ac1b3d12 LT	103	update_tree_entry(desc);
	104	}
	105	}
	106
	107	/* A file entry went away or appeared */
cf995ede	108	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
304de2d2	109	const char *base, int baselen)
ac1b3d12 LT	110	{
	111	unsigned mode;
	112	const char *path;
50f9a858	113	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
fd55a19e	114	int pathlen = tree_entry_len(path, sha1);
ac1b3d12	115
8f67f8ae	116	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
21666f1a	117	enum object_type type;
304de2d2	118	char *newbase = malloc_base(base, baselen, path, pathlen);
ac1b3d12 LT	119	struct tree_desc inner;
ac1b3d12 LT	120	void *tree;
6fda5e51	121	unsigned long size;
ac1b3d12	122
6fda5e51	123	tree = read_sha1_file(sha1, &type, &size);
21666f1a	124	if (!tree \|\| type != OBJ_TREE)
ac1b3d12 LT	125	die("corrupt tree sha %s", sha1_to_hex(sha1));
ac1b3d12 LT	126
df533f34 NE	127	if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
df533f34 NE	128	newbase[baselen + pathlen] = 0;
e3d42c47	129	opt->add_remove(opt, *prefix, mode, sha1, newbase, 0);
df533f34 NE	130	newbase[baselen + pathlen] = '/';
	131	}
	132
6fda5e51	133	init_tree_desc(&inner, tree, size);
304de2d2	134	show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
ac1b3d12 LT	135
	136	free(tree);
	137	free(newbase);
cf995ede	138	} else {
fd55a19e	139	char *fullname = malloc_fullname(base, baselen, path, pathlen);
e3d42c47	140	opt->add_remove(opt, prefix[0], mode, sha1, fullname, 0);
fd55a19e	141	free(fullname);
ac1b3d12	142	}
ac1b3d12 LT	143	}
ac1b3d12 LT	144
7e1ec0d4	145	static void skip_uninteresting(struct tree_desc t, const char base, int baselen, struct diff_options opt, int all_interesting)
5d865017 LT	146	{
5d865017 LT	147	while (t->size) {
475005a1	148	int show = tree_entry_interesting(&t->entry, base, baselen, &opt->pathspec);
7e1ec0d4 EN	149	if (show == 2)
7e1ec0d4 EN	150	*all_interesting = 1;
5d865017 LT	151	if (!show) {
	152	update_tree_entry(t);
	153	continue;
	154	}
	155	/* Skip it all? */
	156	if (show < 0)
	157	t->size = 0;
	158	return;
	159	}
	160	}
	161
ac1b3d12 LT	162	int diff_tree(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
ac1b3d12 LT	163	{
304de2d2	164	int baselen = strlen(base);
7e1ec0d4 EN	165	int all_t1_interesting = 0;
7e1ec0d4 EN	166	int all_t2_interesting = 0;
304de2d2	167
5d865017	168	for (;;) {
90b19941	169	if (DIFF_OPT_TST(opt, QUICK) &&
f245194f	170	DIFF_OPT_TST(opt, HAS_CHANGES))
822cac01	171	break;
66f13625	172	if (opt->pathspec.nr) {
7e1ec0d4 EN	173	if (!all_t1_interesting)
	174	skip_uninteresting(t1, base, baselen, opt,
	175	&all_t1_interesting);
	176	if (!all_t2_interesting)
	177	skip_uninteresting(t2, base, baselen, opt,
	178	&all_t2_interesting);
ac1b3d12 LT	179	}
ac1b3d12 LT	180	if (!t1->size) {
5d865017 LT	181	if (!t2->size)
5d865017 LT	182	break;
304de2d2	183	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	184	update_tree_entry(t2);
	185	continue;
	186	}
	187	if (!t2->size) {
304de2d2	188	show_entry(opt, "-", t1, base, baselen);
ac1b3d12 LT	189	update_tree_entry(t1);
	190	continue;
	191	}
304de2d2	192	switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
ac1b3d12 LT	193	case -1:
	194	update_tree_entry(t1);
	195	continue;
	196	case 0:
	197	update_tree_entry(t1);
	198	/* Fallthrough */
	199	case 1:
	200	update_tree_entry(t2);
	201	continue;
	202	}
7e44c935	203	die("git diff-tree: internal error");
ac1b3d12 LT	204	}
	205	return 0;
	206	}
	207
750f7b66 LT	208	/*
	209	* Does it look like the resulting diff might be due to a rename?
	210	* - single entry
	211	* - not a valid previous file
	212	*/
	213	static inline int diff_might_be_rename(void)
	214	{
	215	return diff_queued_diff.nr == 1 &&
	216	!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
	217	}
	218
	219	static void try_to_follow_renames(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
	220	{
	221	struct diff_options diff_opts;
9f38e1ef LT	222	struct diff_queue_struct *q = &diff_queued_diff;
	223	struct diff_filepair *choice;
	224	const char *paths[1];
750f7b66 LT	225	int i;
750f7b66 LT	226
9f38e1ef LT	227	/* Remove the file creation entry from the diff queue, and remember it */
	228	choice = q->queue[0];
	229	q->nr = 0;
	230
750f7b66	231	diff_setup(&diff_opts);
8f67f8ae	232	DIFF_OPT_SET(&diff_opts, RECURSIVE);
0cdca133	233	DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
750f7b66	234	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
66f13625	235	diff_opts.single_follow = opt->pathspec.raw[0];
6dd4b66f	236	diff_opts.break_opt = opt->break_opt;
750f7b66 LT	237	paths[0] = NULL;
	238	diff_tree_setup_paths(paths, &diff_opts);
	239	if (diff_setup_done(&diff_opts) < 0)
	240	die("unable to set up diff options to follow renames");
	241	diff_tree(t1, t2, base, &diff_opts);
	242	diffcore_std(&diff_opts);
03b69c76	243	diff_tree_release_paths(&diff_opts);
750f7b66	244
9f38e1ef	245	/* Go through the new set of filepairing, and see if we find a more interesting one */
44c48a90	246	opt->found_follow = 0;
9f38e1ef LT	247	for (i = 0; i < q->nr; i++) {
9f38e1ef LT	248	struct diff_filepair *p = q->queue[i];
750f7b66 LT	249
	250	/*
	251	* Found a source? Not only do we use that for the new
9f38e1ef	252	* diff_queued_diff, we will also use that as the path in
750f7b66 LT	253	* the future!
750f7b66 LT	254	*/
66f13625 NTND	255	if ((p->status == 'R' \|\| p->status == 'C') &&
66f13625 NTND	256	!strcmp(p->two->path, opt->pathspec.raw[0])) {
9f38e1ef LT	257	/* Switch the file-pairs around */
	258	q->queue[i] = choice;
	259	choice = p;
	260
	261	/* Update the path we use from now on.. */
03b69c76	262	diff_tree_release_paths(opt);
66f13625 NTND	263	opt->pathspec.raw[0] = xstrdup(p->one->path);
66f13625 NTND	264	diff_tree_setup_paths(opt->pathspec.raw, opt);
44c48a90 JH	265
	266	/*
	267	* The caller expects us to return a set of vanilla
	268	* filepairs to let a later call to diffcore_std()
	269	* it makes to sort the renames out (among other
	270	* things), but we already have found renames
	271	* ourselves; signal diffcore_std() not to muck with
	272	* rename information.
	273	*/
	274	opt->found_follow = 1;
750f7b66 LT	275	break;
	276	}
	277	}
	278
	279	/*
3ea3c215	280	* Then, discard all the non-relevant file pairs...
9f38e1ef LT	281	*/
	282	for (i = 0; i < q->nr; i++) {
	283	struct diff_filepair *p = q->queue[i];
	284	diff_free_filepair(p);
	285	}
	286
	287	/*
	288	* .. and re-instate the one we want (which might be either the
	289	* original one, or the rename/copy we found)
750f7b66	290	*/
9f38e1ef LT	291	q->queue[0] = choice;
9f38e1ef LT	292	q->nr = 1;
750f7b66 LT	293	}
750f7b66 LT	294
ac1b3d12 LT	295	int diff_tree_sha1(const unsigned char old, const unsigned char new, const char base, struct diff_options opt)
	296	{
	297	void tree1, tree2;
	298	struct tree_desc t1, t2;
6fda5e51	299	unsigned long size1, size2;
ac1b3d12 LT	300	int retval;
ac1b3d12 LT	301
6fda5e51	302	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
ac1b3d12 LT	303	if (!tree1)
ac1b3d12 LT	304	die("unable to read source tree (%s)", sha1_to_hex(old));
6fda5e51	305	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
ac1b3d12 LT	306	if (!tree2)
ac1b3d12 LT	307	die("unable to read destination tree (%s)", sha1_to_hex(new));
6fda5e51 LT	308	init_tree_desc(&t1, tree1, size1);
6fda5e51 LT	309	init_tree_desc(&t2, tree2, size2);
ac1b3d12	310	retval = diff_tree(&t1, &t2, base, opt);
39f75d26	311	if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
750f7b66 LT	312	init_tree_desc(&t1, tree1, size1);
	313	init_tree_desc(&t2, tree2, size2);
	314	try_to_follow_renames(&t1, &t2, base, opt);
	315	}
ac1b3d12 LT	316	free(tree1);
	317	free(tree2);
	318	return retval;
	319	}
	320
2b60356d RS	321	int diff_root_tree_sha1(const unsigned char new, const char base, struct diff_options *opt)
	322	{
	323	int retval;
	324	void *tree;
6fda5e51	325	unsigned long size;
2b60356d RS	326	struct tree_desc empty, real;
2b60356d RS	327
6fda5e51	328	tree = read_object_with_reference(new, tree_type, &size, NULL);
2b60356d RS	329	if (!tree)
2b60356d RS	330	die("unable to read root tree (%s)", sha1_to_hex(new));
6fda5e51	331	init_tree_desc(&real, tree, size);
2b60356d	332
6fda5e51	333	init_tree_desc(&empty, "", 0);
2b60356d RS	334	retval = diff_tree(&empty, &real, base, opt);
	335	free(tree);
	336	return retval;
	337	}
	338
a8baa7b9	339	void diff_tree_release_paths(struct diff_options *opt)
ac1b3d12	340	{
66f13625	341	free_pathspec(&opt->pathspec);
a8baa7b9 JH	342	}
	343
	344	void diff_tree_setup_paths(const char *p, struct diff_options opt)
	345	{
66f13625	346	init_pathspec(&opt->pathspec, p);
ac1b3d12	347	}