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

/*
 * Builtin "git diff"
 *
 * Copyright (c) 2006 Junio C Hamano
 */
#include "cache.h"
#include "color.h"
#include "commit.h"
#include "blob.h"
#include "tag.h"
#include "diff.h"
#include "diffcore.h"
#include "revision.h"
#include "log-tree.h"
#include "builtin.h"

struct blobinfo {
	unsigned char sha1[20];
	const char *name;
	unsigned mode;
};

static const char builtin_diff_usage[] =
"git diff <options> <rev>{0,2} -- <path>*";

static void stuff_change(struct diff_options *opt,
			 unsigned old_mode, unsigned new_mode,
			 const unsigned char *old_sha1,
			 const unsigned char *new_sha1,
			 const char *old_name,
			 const char *new_name)
{
	struct diff_filespec *one, *two;

	if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
	    !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
		return;

	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
		unsigned tmp;
		const unsigned char *tmp_u;
		const char *tmp_c;
		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
		tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
		tmp_c = old_name; old_name = new_name; new_name = tmp_c;
	}

	if (opt->prefix &&
	    (strncmp(old_name, opt->prefix, opt->prefix_length) ||
	     strncmp(new_name, opt->prefix, opt->prefix_length)))
		return;

	one = alloc_filespec(old_name);
	two = alloc_filespec(new_name);
	fill_filespec(one, old_sha1, old_mode);
	fill_filespec(two, new_sha1, new_mode);

	diff_queue(&diff_queued_diff, one, two);
}

static int builtin_diff_b_f(struct rev_info *revs,
			    int argc, const char **argv,
			    struct blobinfo *blob,
			    const char *path)
{
	/* Blob vs file in the working tree*/
	struct stat st;

	if (argc > 1)
		usage(builtin_diff_usage);

	if (lstat(path, &st))
		die("'%s': %s", path, strerror(errno));
	if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
		die("'%s': not a regular file or symlink", path);

	if (blob[0].mode == S_IFINVALID)
		blob[0].mode = canon_mode(st.st_mode);

	stuff_change(&revs->diffopt,
		     blob[0].mode, canon_mode(st.st_mode),
		     blob[0].sha1, null_sha1,
		     path, path);
	diffcore_std(&revs->diffopt);
	diff_flush(&revs->diffopt);
	return 0;
}

static int builtin_diff_blobs(struct rev_info *revs,
			      int argc, const char **argv,
			      struct blobinfo *blob)
{
	unsigned mode = canon_mode(S_IFREG | 0644);

	if (argc > 1)
		usage(builtin_diff_usage);

	if (blob[0].mode == S_IFINVALID)
		blob[0].mode = mode;

	if (blob[1].mode == S_IFINVALID)
		blob[1].mode = mode;

	stuff_change(&revs->diffopt,
		     blob[0].mode, blob[1].mode,
		     blob[0].sha1, blob[1].sha1,
		     blob[0].name, blob[1].name);
	diffcore_std(&revs->diffopt);
	diff_flush(&revs->diffopt);
	return 0;
}

static int builtin_diff_index(struct rev_info *revs,
			      int argc, const char **argv)
{
	int cached = 0;
	while (1 < argc) {
		const char *arg = argv[1];
		if (!strcmp(arg, "--cached"))
			cached = 1;
		else
			usage(builtin_diff_usage);
		argv++; argc--;
	}
	/*
	 * Make sure there is one revision (i.e. pending object),
	 * and there is no revision filtering parameters.
	 */
	if (revs->pending.nr != 1 ||
	    revs->max_count != -1 || revs->min_age != -1 ||
	    revs->max_age != -1)
		usage(builtin_diff_usage);
	if (read_cache() < 0) {
		perror("read_cache");
		return -1;
	}
	return run_diff_index(revs, cached);
}

static int builtin_diff_tree(struct rev_info *revs,
			     int argc, const char **argv,
			     struct object_array_entry *ent)
{
	const unsigned char *(sha1[2]);
	int swap = 0;

	if (argc > 1)
		usage(builtin_diff_usage);

	/* We saw two trees, ent[0] and ent[1].
	 * if ent[1] is uninteresting, they are swapped
	 */
	if (ent[1].item->flags & UNINTERESTING)
		swap = 1;
	sha1[swap] = ent[0].item->sha1;
	sha1[1-swap] = ent[1].item->sha1;
	diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
	log_tree_diff_flush(revs);
	return 0;
}

static int builtin_diff_combined(struct rev_info *revs,
				 int argc, const char **argv,
				 struct object_array_entry *ent,
				 int ents)
{
	const unsigned char (*parent)[20];
	int i;

	if (argc > 1)
		usage(builtin_diff_usage);

	if (!revs->dense_combined_merges && !revs->combine_merges)
		revs->dense_combined_merges = revs->combine_merges = 1;
	parent = xmalloc(ents * sizeof(*parent));
	/* Again, the revs are all reverse */
	for (i = 0; i < ents; i++)
		hashcpy((unsigned char *)(parent + i),
			ent[ents - 1 - i].item->sha1);
	diff_tree_combined(parent[0], parent + 1, ents - 1,
			   revs->dense_combined_merges, revs);
	return 0;
}

static void refresh_index_quietly(void)
{
	struct lock_file *lock_file;
	int fd;

	lock_file = xcalloc(1, sizeof(struct lock_file));
	fd = hold_locked_index(lock_file, 0);
	if (fd < 0)
		return;
	discard_cache();
	read_cache();
	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);

	if (active_cache_changed &&
	    !write_cache(fd, active_cache, active_nr))
		commit_locked_index(lock_file);

	rollback_lock_file(lock_file);
}

static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
{
	int result;
	unsigned int options = 0;

	while (1 < argc && argv[1][0] == '-') {
		if (!strcmp(argv[1], "--base"))
			revs->max_count = 1;
		else if (!strcmp(argv[1], "--ours"))
			revs->max_count = 2;
		else if (!strcmp(argv[1], "--theirs"))
			revs->max_count = 3;
		else if (!strcmp(argv[1], "-q"))
			options |= DIFF_SILENT_ON_REMOVED;
		else
			return error("invalid option: %s", argv[1]);
		argv++; argc--;
	}

	if (revs->max_count == -1 &&
	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
		revs->combine_merges = revs->dense_combined_merges = 1;

	if (read_cache() < 0) {
		perror("read_cache");
		return -1;
	}
	result = run_diff_files(revs, options);
	return diff_result_code(&revs->diffopt, result);
}

int cmd_diff(int argc, const char **argv, const char *prefix)
{
	int i;
	struct rev_info rev;
	struct object_array_entry ent[100];
	int ents = 0, blobs = 0, paths = 0;
	const char *path = NULL;
	struct blobinfo blob[2];
	int nongit;
	int result = 0;

	/*
	 * We could get N tree-ish in the rev.pending_objects list.
	 * Also there could be M blobs there, and P pathspecs.
	 *
	 * N=0, M=0:
	 *	cache vs files (diff-files)
	 * N=0, M=2:
	 *      compare two random blobs.  P must be zero.
	 * N=0, M=1, P=1:
	 *	compare a blob with a working tree file.
	 *
	 * N=1, M=0:
	 *      tree vs cache (diff-index --cached)
	 *
	 * N=2, M=0:
	 *      tree vs tree (diff-tree)
	 *
	 * N=0, M=0, P=2:
	 *      compare two filesystem entities (aka --no-index).
	 *
	 * Other cases are errors.
	 */

	prefix = setup_git_directory_gently(&nongit);
	git_config(git_diff_ui_config, NULL);

	if (diff_use_color_default == -1)
		diff_use_color_default = git_use_color_default;

	init_revisions(&rev, prefix);

	/* If this is a no-index diff, just run it and exit there. */
	diff_no_index(&rev, argc, argv, nongit, prefix);

	/* Otherwise, we are doing the usual "git" diff */
	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;

	if (nongit)
		die("Not a git repository");
	argc = setup_revisions(argc, argv, &rev, NULL);
	if (!rev.diffopt.output_format) {
		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
		if (diff_setup_done(&rev.diffopt) < 0)
			die("diff_setup_done failed");
	}
	DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);

	/*
	 * If the user asked for our exit code then don't start a
	 * pager or we would end up reporting its exit code instead.
	 */
	if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
	    check_pager_config("diff") != 0)
		setup_pager();

	/*
	 * Do we have --cached and not have a pending object, then
	 * default to HEAD by hand.  Eek.
	 */
	if (!rev.pending.nr) {
		int i;
		for (i = 1; i < argc; i++) {
			const char *arg = argv[i];
			if (!strcmp(arg, "--"))
				break;
			else if (!strcmp(arg, "--cached")) {
				add_head_to_pending(&rev);
				if (!rev.pending.nr)
					die("No HEAD commit to compare with (yet)");
				break;
			}
		}
	}

	for (i = 0; i < rev.pending.nr; i++) {
		struct object_array_entry *list = rev.pending.objects+i;
		struct object *obj = list->item;
		const char *name = list->name;
		int flags = (obj->flags & UNINTERESTING);
		if (!obj->parsed)
			obj = parse_object(obj->sha1);
		obj = deref_tag(obj, NULL, 0);
		if (!obj)
			die("invalid object '%s' given.", name);
		if (obj->type == OBJ_COMMIT)
			obj = &((struct commit *)obj)->tree->object;
		if (obj->type == OBJ_TREE) {
			if (ARRAY_SIZE(ent) <= ents)
				die("more than %d trees given: '%s'",
				    (int) ARRAY_SIZE(ent), name);
			obj->flags |= flags;
			ent[ents].item = obj;
			ent[ents].name = name;
			ents++;
			continue;
		}
		if (obj->type == OBJ_BLOB) {
			if (2 <= blobs)
				die("more than two blobs given: '%s'", name);
			hashcpy(blob[blobs].sha1, obj->sha1);
			blob[blobs].name = name;
			blob[blobs].mode = list->mode;
			blobs++;
			continue;

		}
		die("unhandled object '%s' given.", name);
	}
	if (rev.prune_data) {
		const char **pathspec = rev.prune_data;
		while (*pathspec) {
			if (!path)
				path = *pathspec;
			paths++;
			pathspec++;
		}
	}

	/*
	 * Now, do the arguments look reasonable?
	 */
	if (!ents) {
		switch (blobs) {
		case 0:
			result = builtin_diff_files(&rev, argc, argv);
			break;
		case 1:
			if (paths != 1)
				usage(builtin_diff_usage);
			result = builtin_diff_b_f(&rev, argc, argv, blob, path);
			break;
		case 2:
			if (paths)
				usage(builtin_diff_usage);
			result = builtin_diff_blobs(&rev, argc, argv, blob);
			break;
		default:
			usage(builtin_diff_usage);
		}
	}
	else if (blobs)
		usage(builtin_diff_usage);
	else if (ents == 1)
		result = builtin_diff_index(&rev, argc, argv);
	else if (ents == 2)
		result = builtin_diff_tree(&rev, argc, argv, ent);
	else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
		/* diff A...B where there is one sane merge base between
		 * A and B.  We have ent[0] == merge-base, ent[1] == A,
		 * and ent[2] == B.  Show diff between the base and B.
		 */
		ent[1] = ent[2];
		result = builtin_diff_tree(&rev, argc, argv, ent);
	}
	else
		result = builtin_diff_combined(&rev, argc, argv,
					     ent, ents);
	result = diff_result_code(&rev.diffopt, result);
	if (1 < rev.diffopt.skip_stat_unmatch)
		refresh_index_quietly();
	return result;
}
Commit	Line	Data
65056021 JH	1	/*
	2	* Builtin "git diff"
	3	*
	4	* Copyright (c) 2006 Junio C Hamano
	5	*/
	6	#include "cache.h"
6b2f2d98	7	#include "color.h"
65056021 JH	8	#include "commit.h"
	9	#include "blob.h"
	10	#include "tag.h"
	11	#include "diff.h"
	12	#include "diffcore.h"
	13	#include "revision.h"
	14	#include "log-tree.h"
	15	#include "builtin.h"
	16
65056021 JH	17	struct blobinfo {
	18	unsigned char sha1[20];
	19	const char *name;
01618a3a	20	unsigned mode;
65056021 JH	21	};
	22
	23	static const char builtin_diff_usage[] =
1b1dd23f	24	"git diff <options> <rev>{0,2} -- <path>*";
65056021	25
65056021 JH	26	static void stuff_change(struct diff_options *opt,
	27	unsigned old_mode, unsigned new_mode,
	28	const unsigned char *old_sha1,
	29	const unsigned char *new_sha1,
	30	const char *old_name,
	31	const char *new_name)
	32	{
	33	struct diff_filespec one, two;
	34
0bef57ee	35	if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
43342941	36	!hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
65056021 JH	37	return;
65056021 JH	38
8f67f8ae	39	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
65056021	40	unsigned tmp;
d92f1dc6	41	const unsigned char *tmp_u;
65056021 JH	42	const char *tmp_c;
	43	tmp = old_mode; old_mode = new_mode; new_mode = tmp;
	44	tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
	45	tmp_c = old_name; old_name = new_name; new_name = tmp_c;
	46	}
cd676a51 JH	47
	48	if (opt->prefix &&
	49	(strncmp(old_name, opt->prefix, opt->prefix_length) \|\|
	50	strncmp(new_name, opt->prefix, opt->prefix_length)))
	51	return;
	52
65056021 JH	53	one = alloc_filespec(old_name);
	54	two = alloc_filespec(new_name);
	55	fill_filespec(one, old_sha1, old_mode);
	56	fill_filespec(two, new_sha1, new_mode);
	57
65056021 JH	58	diff_queue(&diff_queued_diff, one, two);
	59	}
	60
	61	static int builtin_diff_b_f(struct rev_info *revs,
	62	int argc, const char **argv,
	63	struct blobinfo *blob,
	64	const char *path)
	65	{
	66	/* Blob vs file in the working tree*/
	67	struct stat st;
	68
a610786f TH	69	if (argc > 1)
	70	usage(builtin_diff_usage);
	71
65056021 JH	72	if (lstat(path, &st))
	73	die("'%s': %s", path, strerror(errno));
	74	if (!(S_ISREG(st.st_mode) \|\| S_ISLNK(st.st_mode)))
	75	die("'%s': not a regular file or symlink", path);
01618a3a MK	76
	77	if (blob[0].mode == S_IFINVALID)
	78	blob[0].mode = canon_mode(st.st_mode);
	79
65056021	80	stuff_change(&revs->diffopt,
01618a3a	81	blob[0].mode, canon_mode(st.st_mode),
65056021	82	blob[0].sha1, null_sha1,
065e0b12	83	path, path);
65056021 JH	84	diffcore_std(&revs->diffopt);
	85	diff_flush(&revs->diffopt);
	86	return 0;
	87	}
	88
	89	static int builtin_diff_blobs(struct rev_info *revs,
	90	int argc, const char **argv,
	91	struct blobinfo *blob)
	92	{
65056021 JH	93	unsigned mode = canon_mode(S_IFREG \| 0644);
65056021 JH	94
a610786f TH	95	if (argc > 1)
	96	usage(builtin_diff_usage);
	97
01618a3a MK	98	if (blob[0].mode == S_IFINVALID)
	99	blob[0].mode = mode;
	100
	101	if (blob[1].mode == S_IFINVALID)
	102	blob[1].mode = mode;
	103
65056021	104	stuff_change(&revs->diffopt,
01618a3a	105	blob[0].mode, blob[1].mode,
f82cd3c6	106	blob[0].sha1, blob[1].sha1,
53dd8a9c	107	blob[0].name, blob[1].name);
65056021 JH	108	diffcore_std(&revs->diffopt);
	109	diff_flush(&revs->diffopt);
	110	return 0;
	111	}
	112
	113	static int builtin_diff_index(struct rev_info *revs,
	114	int argc, const char **argv)
	115	{
	116	int cached = 0;
	117	while (1 < argc) {
	118	const char *arg = argv[1];
f2dd1c9a	119	if (!strcmp(arg, "--cached"))
65056021	120	cached = 1;
65056021 JH	121	else
	122	usage(builtin_diff_usage);
	123	argv++; argc--;
	124	}
	125	/*
	126	* Make sure there is one revision (i.e. pending object),
	127	* and there is no revision filtering parameters.
	128	*/
1f1e895f	129	if (revs->pending.nr != 1 \|\|
65056021 JH	130	revs->max_count != -1 \|\| revs->min_age != -1 \|\|
	131	revs->max_age != -1)
	132	usage(builtin_diff_usage);
b4e1e4a7 JH	133	if (read_cache() < 0) {
	134	perror("read_cache");
	135	return -1;
	136	}
65056021 JH	137	return run_diff_index(revs, cached);
	138	}
	139
	140	static int builtin_diff_tree(struct rev_info *revs,
	141	int argc, const char **argv,
1f1e895f	142	struct object_array_entry *ent)
65056021	143	{
65056021	144	const unsigned char *(sha1[2]);
1f1e895f	145	int swap = 0;
a610786f TH	146
	147	if (argc > 1)
	148	usage(builtin_diff_usage);
0fe7c1de JH	149
0fe7c1de JH	150	/* We saw two trees, ent[0] and ent[1].
82e5a82f	151	* if ent[1] is uninteresting, they are swapped
0fe7c1de	152	*/
1f1e895f LT	153	if (ent[1].item->flags & UNINTERESTING)
1f1e895f LT	154	swap = 1;
65056021 JH	155	sha1[swap] = ent[0].item->sha1;
	156	sha1[1-swap] = ent[1].item->sha1;
	157	diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
	158	log_tree_diff_flush(revs);
	159	return 0;
	160	}
	161
0fe7c1de JH	162	static int builtin_diff_combined(struct rev_info *revs,
0fe7c1de JH	163	int argc, const char **argv,
1f1e895f	164	struct object_array_entry *ent,
0fe7c1de JH	165	int ents)
	166	{
	167	const unsigned char (*parent)[20];
	168	int i;
	169
a610786f TH	170	if (argc > 1)
	171	usage(builtin_diff_usage);
	172
0fe7c1de JH	173	if (!revs->dense_combined_merges && !revs->combine_merges)
	174	revs->dense_combined_merges = revs->combine_merges = 1;
	175	parent = xmalloc(ents * sizeof(*parent));
	176	/* Again, the revs are all reverse */
	177	for (i = 0; i < ents; i++)
75b62b48 JS	178	hashcpy((unsigned char *)(parent + i),
75b62b48 JS	179	ent[ents - 1 - i].item->sha1);
0fe7c1de JH	180	diff_tree_combined(parent[0], parent + 1, ents - 1,
	181	revs->dense_combined_merges, revs);
	182	return 0;
	183	}
	184
aecbf914 JH	185	static void refresh_index_quietly(void)
	186	{
	187	struct lock_file *lock_file;
	188	int fd;
	189
	190	lock_file = xcalloc(1, sizeof(struct lock_file));
	191	fd = hold_locked_index(lock_file, 0);
	192	if (fd < 0)
	193	return;
	194	discard_cache();
	195	read_cache();
	196	refresh_cache(REFRESH_QUIET\|REFRESH_UNMERGED);
fbbdbfc3 JH	197
fbbdbfc3 JH	198	if (active_cache_changed &&
4ed7cd3a	199	!write_cache(fd, active_cache, active_nr))
fbbdbfc3 JH	200	commit_locked_index(lock_file);
fbbdbfc3 JH	201
aecbf914 JH	202	rollback_lock_file(lock_file);
	203	}
	204
0569e9b8 JH	205	static int builtin_diff_files(struct rev_info revs, int argc, const char *argv)
	206	{
	207	int result;
	208	unsigned int options = 0;
	209
	210	while (1 < argc && argv[1][0] == '-') {
	211	if (!strcmp(argv[1], "--base"))
	212	revs->max_count = 1;
	213	else if (!strcmp(argv[1], "--ours"))
	214	revs->max_count = 2;
	215	else if (!strcmp(argv[1], "--theirs"))
	216	revs->max_count = 3;
	217	else if (!strcmp(argv[1], "-q"))
	218	options \|= DIFF_SILENT_ON_REMOVED;
	219	else
	220	return error("invalid option: %s", argv[1]);
	221	argv++; argc--;
	222	}
	223
	224	if (revs->max_count == -1 &&
	225	(revs->diffopt.output_format & DIFF_FORMAT_PATCH))
	226	revs->combine_merges = revs->dense_combined_merges = 1;
	227
	228	if (read_cache() < 0) {
	229	perror("read_cache");
	230	return -1;
	231	}
	232	result = run_diff_files(revs, options);
	233	return diff_result_code(&revs->diffopt, result);
	234	}
	235
a633fca0	236	int cmd_diff(int argc, const char *argv, const char prefix)
65056021	237	{
1f1e895f	238	int i;
65056021	239	struct rev_info rev;
1f1e895f	240	struct object_array_entry ent[100];
65056021	241	int ents = 0, blobs = 0, paths = 0;
a633fca0	242	const char *path = NULL;
65056021	243	struct blobinfo blob[2];
af05d679	244	int nongit;
41bbf9d5	245	int result = 0;
65056021 JH	246
	247	/*
	248	* We could get N tree-ish in the rev.pending_objects list.
	249	* Also there could be M blobs there, and P pathspecs.
	250	*
	251	* N=0, M=0:
	252	* cache vs files (diff-files)
	253	* N=0, M=2:
	254	* compare two random blobs. P must be zero.
	255	* N=0, M=1, P=1:
	256	* compare a blob with a working tree file.
	257	*
	258	* N=1, M=0:
	259	* tree vs cache (diff-index --cached)
	260	*
	261	* N=2, M=0:
	262	* tree vs tree (diff-tree)
	263	*
0569e9b8 JH	264	* N=0, M=0, P=2:
	265	* compare two filesystem entities (aka --no-index).
	266	*
65056021 JH	267	* Other cases are errors.
65056021 JH	268	*/
230f544e	269
d516c2d1	270	prefix = setup_git_directory_gently(&nongit);
ef90d6d4	271	git_config(git_diff_ui_config, NULL);
6b2f2d98 MK	272
	273	if (diff_use_color_default == -1)
	274	diff_use_color_default = git_use_color_default;
	275
db6296a5	276	init_revisions(&rev, prefix);
0569e9b8 JH	277
	278	/* If this is a no-index diff, just run it and exit there. */
	279	diff_no_index(&rev, argc, argv, nongit, prefix);
	280
	281	/* Otherwise, we are doing the usual "git" diff */
aecbf914	282	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
65056021	283
0569e9b8 JH	284	if (nongit)
	285	die("Not a git repository");
	286	argc = setup_revisions(argc, argv, &rev, NULL);
047fbe90	287	if (!rev.diffopt.output_format) {
c9b5ef99	288	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
72ee96c0 JH	289	if (diff_setup_done(&rev.diffopt) < 0)
72ee96c0 JH	290	die("diff_setup_done failed");
047fbe90	291	}
8f67f8ae PH	292	DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
8f67f8ae PH	293	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
c9b5ef99	294
da31b358 JH	295	/*
da31b358 JH	296	* If the user asked for our exit code then don't start a
89d07f75 RS	297	* pager or we would end up reporting its exit code instead.
89d07f75 RS	298	*/
8f0359f0 AR	299	if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
8f0359f0 AR	300	check_pager_config("diff") != 0)
89d07f75 RS	301	setup_pager();
89d07f75 RS	302
0569e9b8 JH	303	/*
0569e9b8 JH	304	* Do we have --cached and not have a pending object, then
65056021 JH	305	* default to HEAD by hand. Eek.
65056021 JH	306	*/
1f1e895f	307	if (!rev.pending.nr) {
65056021 JH	308	int i;
	309	for (i = 1; i < argc; i++) {
	310	const char *arg = argv[i];
	311	if (!strcmp(arg, "--"))
	312	break;
	313	else if (!strcmp(arg, "--cached")) {
3384a2df	314	add_head_to_pending(&rev);
6c09c451 JH	315	if (!rev.pending.nr)
6c09c451 JH	316	die("No HEAD commit to compare with (yet)");
65056021 JH	317	break;
	318	}
	319	}
	320	}
	321
1f1e895f LT	322	for (i = 0; i < rev.pending.nr; i++) {
1f1e895f LT	323	struct object_array_entry *list = rev.pending.objects+i;
65056021 JH	324	struct object *obj = list->item;
	325	const char *name = list->name;
	326	int flags = (obj->flags & UNINTERESTING);
	327	if (!obj->parsed)
	328	obj = parse_object(obj->sha1);
	329	obj = deref_tag(obj, NULL, 0);
	330	if (!obj)
	331	die("invalid object '%s' given.", name);
1974632c	332	if (obj->type == OBJ_COMMIT)
65056021	333	obj = &((struct commit *)obj)->tree->object;
1974632c	334	if (obj->type == OBJ_TREE) {
0fe7c1de JH	335	if (ARRAY_SIZE(ent) <= ents)
0fe7c1de JH	336	die("more than %d trees given: '%s'",
334b506a	337	(int) ARRAY_SIZE(ent), name);
65056021 JH	338	obj->flags \|= flags;
	339	ent[ents].item = obj;
	340	ent[ents].name = name;
	341	ents++;
	342	continue;
	343	}
1974632c	344	if (obj->type == OBJ_BLOB) {
65056021 JH	345	if (2 <= blobs)
65056021 JH	346	die("more than two blobs given: '%s'", name);
e702496e	347	hashcpy(blob[blobs].sha1, obj->sha1);
65056021	348	blob[blobs].name = name;
01618a3a	349	blob[blobs].mode = list->mode;
65056021 JH	350	blobs++;
65056021 JH	351	continue;
230f544e	352
65056021 JH	353	}
	354	die("unhandled object '%s' given.", name);
	355	}
	356	if (rev.prune_data) {
	357	const char **pathspec = rev.prune_data;
	358	while (*pathspec) {
	359	if (!path)
	360	path = *pathspec;
	361	paths++;
	362	pathspec++;
	363	}
	364	}
	365
	366	/*
	367	* Now, do the arguments look reasonable?
	368	*/
	369	if (!ents) {
	370	switch (blobs) {
	371	case 0:
0569e9b8	372	result = builtin_diff_files(&rev, argc, argv);
65056021 JH	373	break;
	374	case 1:
	375	if (paths != 1)
	376	usage(builtin_diff_usage);
41bbf9d5	377	result = builtin_diff_b_f(&rev, argc, argv, blob, path);
65056021 JH	378	break;
65056021 JH	379	case 2:
0fe7c1de JH	380	if (paths)
0fe7c1de JH	381	usage(builtin_diff_usage);
41bbf9d5	382	result = builtin_diff_blobs(&rev, argc, argv, blob);
65056021 JH	383	break;
	384	default:
	385	usage(builtin_diff_usage);
	386	}
	387	}
	388	else if (blobs)
	389	usage(builtin_diff_usage);
	390	else if (ents == 1)
41bbf9d5	391	result = builtin_diff_index(&rev, argc, argv);
65056021	392	else if (ents == 2)
41bbf9d5	393	result = builtin_diff_tree(&rev, argc, argv, ent);
9919f41c JH	394	else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
	395	/* diff A...B where there is one sane merge base between
	396	* A and B. We have ent[0] == merge-base, ent[1] == A,
	397	* and ent[2] == B. Show diff between the base and B.
	398	*/
306ea2df	399	ent[1] = ent[2];
41bbf9d5	400	result = builtin_diff_tree(&rev, argc, argv, ent);
9919f41c	401	}
0fe7c1de	402	else
41bbf9d5	403	result = builtin_diff_combined(&rev, argc, argv,
9919f41c	404	ent, ents);
da31b358	405	result = diff_result_code(&rev.diffopt, result);
aecbf914 JH	406	if (1 < rev.diffopt.skip_stat_unmatch)
aecbf914 JH	407	refresh_index_quietly();
41bbf9d5	408	return result;
65056021	409	}