aboutsummaryrefslogtreecommitdiff
path: root/builtin/reset.c
blob: 60048030dd4d05e9938f298002d02afc31528bf1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
/*
 * "git reset" builtin command
 *
 * Copyright (c) 2007 Carlos Rica
 *
 * Based on git-reset.sh, which is
 *
 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
 */
#include "builtin.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "run-command.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"
#include "branch.h"
#include "parse-options.h"
#include "unpack-trees.h"
#include "cache-tree.h"

static const char * const git_reset_usage[] = {
	N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
	N_("git reset [-q] <tree-ish> [--] <paths>..."),
	N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
	NULL
};

enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
static const char *reset_type_names[] = {
	N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
};

static inline int is_merge(void)
{
	return !access(git_path("MERGE_HEAD"), F_OK);
}

static int reset_index(const unsigned char *sha1, int reset_type, int quiet)
{
	int nr = 1;
	struct tree_desc desc[2];
	struct tree *tree;
	struct unpack_trees_options opts;

	memset(&opts, 0, sizeof(opts));
	opts.head_idx = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.fn = oneway_merge;
	opts.merge = 1;
	if (!quiet)
		opts.verbose_update = 1;
	switch (reset_type) {
	case KEEP:
	case MERGE:
		opts.update = 1;
		break;
	case HARD:
		opts.update = 1;
		/* fallthrough */
	default:
		opts.reset = 1;
	}

	read_cache_unmerged();

	if (reset_type == KEEP) {
		unsigned char head_sha1[20];
		if (get_sha1("HEAD", head_sha1))
			return error(_("You do not have a valid HEAD."));
		if (!fill_tree_descriptor(desc, head_sha1))
			return error(_("Failed to find tree of HEAD."));
		nr++;
		opts.fn = twoway_merge;
	}

	if (!fill_tree_descriptor(desc + nr - 1, sha1))
		return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
	if (unpack_trees(nr, desc, &opts))
		return -1;

	if (reset_type == MIXED || reset_type == HARD) {
		tree = parse_tree_indirect(sha1);
		prime_cache_tree(&active_cache_tree, tree);
	}

	return 0;
}

static void print_new_head_line(struct commit *commit)
{
	const char *hex, *body;
	char *msg;

	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	printf(_("HEAD is now at %s"), hex);
	msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
	body = strstr(msg, "\n\n");
	if (body) {
		const char *eol;
		size_t len;
		body += 2;
		eol = strchr(body, '\n');
		len = eol ? eol - body : strlen(body);
		printf(" %.*s\n", (int) len, body);
	}
	else
		printf("\n");
	logmsg_free(msg, commit);
}

static void update_index_from_diff(struct diff_queue_struct *q,
		struct diff_options *opt, void *data)
{
	int i;

	for (i = 0; i < q->nr; i++) {
		struct diff_filespec *one = q->queue[i]->one;
		if (one->mode && !is_null_sha1(one->sha1)) {
			struct cache_entry *ce;
			ce = make_cache_entry(one->mode, one->sha1, one->path,
				0, 0);
			if (!ce)
				die(_("make_cache_entry failed for path '%s'"),
				    one->path);
			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
				ADD_CACHE_OK_TO_REPLACE);
		} else
			remove_file_from_cache(one->path);
	}
}

static int read_from_tree(const struct pathspec *pathspec,
			  unsigned char *tree_sha1)
{
	struct diff_options opt;

	memset(&opt, 0, sizeof(opt));
	copy_pathspec(&opt.pathspec, pathspec);
	opt.output_format = DIFF_FORMAT_CALLBACK;
	opt.format_callback = update_index_from_diff;

	if (do_diff_cache(tree_sha1, &opt))
		return 1;
	diffcore_std(&opt);
	diff_flush(&opt);
	free_pathspec(&opt.pathspec);

	return 0;
}

static void set_reflog_message(struct strbuf *sb, const char *action,
			       const char *rev)
{
	const char *rla = getenv("GIT_REFLOG_ACTION");

	strbuf_reset(sb);
	if (rla)
		strbuf_addf(sb, "%s: %s", rla, action);
	else if (rev)
		strbuf_addf(sb, "reset: moving to %s", rev);
	else
		strbuf_addf(sb, "reset: %s", action);
}

static void die_if_unmerged_cache(int reset_type)
{
	if (is_merge() || unmerged_cache())
		die(_("Cannot do a %s reset in the middle of a merge."),
		    _(reset_type_names[reset_type]));

}

static void parse_args(struct pathspec *pathspec,
		       const char **argv, const char *prefix,
		       int patch_mode,
		       const char **rev_ret)
{
	const char *rev = "HEAD";
	unsigned char unused[20];
	/*
	 * Possible arguments are:
	 *
	 * git reset [-opts] [<rev>]
	 * git reset [-opts] <tree> [<paths>...]
	 * git reset [-opts] <tree> -- [<paths>...]
	 * git reset [-opts] -- [<paths>...]
	 * git reset [-opts] <paths>...
	 *
	 * At this point, argv points immediately after [-opts].
	 */

	if (argv[0]) {
		if (!strcmp(argv[0], "--")) {
			argv++; /* reset to HEAD, possibly with paths */
		} else if (argv[1] && !strcmp(argv[1], "--")) {
			rev = argv[0];
			argv += 2;
		}
		/*
		 * Otherwise, argv[0] could be either <rev> or <paths> and
		 * has to be unambiguous. If there is a single argument, it
		 * can not be a tree
		 */
		else if ((!argv[1] && !get_sha1_committish(argv[0], unused)) ||
			 (argv[1] && !get_sha1_treeish(argv[0], unused))) {
			/*
			 * Ok, argv[0] looks like a commit/tree; it should not
			 * be a filename.
			 */
			verify_non_filename(prefix, argv[0]);
			rev = *argv++;
		} else {
			/* Otherwise we treat this as a filename */
			verify_filename(prefix, argv[0], 1);
		}
	}
	*rev_ret = rev;

	if (read_cache() < 0)
		die(_("index file corrupt"));

	parse_pathspec(pathspec, 0,
		       PATHSPEC_PREFER_FULL |
		       PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP |
		       (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
		       prefix, argv);
}

static int reset_refs(const char *rev, const unsigned char *sha1)
{
	int update_ref_status;
	struct strbuf msg = STRBUF_INIT;
	unsigned char *orig = NULL, sha1_orig[20],
		*old_orig = NULL, sha1_old_orig[20];

	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
		old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
		orig = sha1_orig;
		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	} else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig, 0);
	set_reflog_message(&msg, "updating HEAD", rev);
	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
	strbuf_release(&msg);
	return update_ref_status;
}

int cmd_reset(int argc, const char **argv, const char *prefix)
{
	int reset_type = NONE, update_ref_status = 0, quiet = 0;
	int patch_mode = 0, unborn;
	const char *rev;
	unsigned char sha1[20];
	struct pathspec pathspec;
	const struct option options[] = {
		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
		OPT_SET_INT(0, "mixed", &reset_type,
						N_("reset HEAD and index"), MIXED),
		OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
		OPT_SET_INT(0, "hard", &reset_type,
				N_("reset HEAD, index and working tree"), HARD),
		OPT_SET_INT(0, "merge", &reset_type,
				N_("reset HEAD, index and working tree"), MERGE),
		OPT_SET_INT(0, "keep", &reset_type,
				N_("reset HEAD but keep local changes"), KEEP),
		OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
		OPT_END()
	};

	git_config(git_default_config, NULL);

	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
						PARSE_OPT_KEEP_DASHDASH);
	parse_args(&pathspec, argv, prefix, patch_mode, &rev);

	unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", sha1);
	if (unborn) {
		/* reset on unborn branch: treat as reset to empty tree */
		hashcpy(sha1, EMPTY_TREE_SHA1_BIN);
	} else if (!pathspec.nr) {
		struct commit *commit;
		if (get_sha1_committish(rev, sha1))
			die(_("Failed to resolve '%s' as a valid revision."), rev);
		commit = lookup_commit_reference(sha1);
		if (!commit)
			die(_("Could not parse object '%s'."), rev);
		hashcpy(sha1, commit->object.sha1);
	} else {
		struct tree *tree;
		if (get_sha1_treeish(rev, sha1))
			die(_("Failed to resolve '%s' as a valid tree."), rev);
		tree = parse_tree_indirect(sha1);
		if (!tree)
			die(_("Could not parse object '%s'."), rev);
		hashcpy(sha1, tree->object.sha1);
	}

	if (patch_mode) {
		if (reset_type != NONE)
			die(_("--patch is incompatible with --{hard,mixed,soft}"));
		return run_add_interactive(rev, "--patch=reset", &pathspec);
	}

	/* git reset tree [--] paths... can be used to
	 * load chosen paths from the tree into the index without
	 * affecting the working tree nor HEAD. */
	if (pathspec.nr) {
		if (reset_type == MIXED)
			warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
		else if (reset_type != NONE)
			die(_("Cannot do %s reset with paths."),
					_(reset_type_names[reset_type]));
	}
	if (reset_type == NONE)
		reset_type = MIXED; /* by default */

	if (reset_type != SOFT && reset_type != MIXED)
		setup_work_tree();

	if (reset_type == MIXED && is_bare_repository())
		die(_("%s reset is not allowed in a bare repository"),
		    _(reset_type_names[reset_type]));

	/* Soft reset does not touch the index file nor the working tree
	 * at all, but requires them in a good order.  Other resets reset
	 * the index file to the tree object we are switching to. */
	if (reset_type == SOFT || reset_type == KEEP)
		die_if_unmerged_cache(reset_type);

	if (reset_type != SOFT) {
		struct lock_file *lock = xcalloc(1, sizeof(*lock));
		int newfd = hold_locked_index(lock, 1);
		if (reset_type == MIXED) {
			int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
			if (read_from_tree(&pathspec, sha1))
				return 1;
			refresh_index(&the_index, flags, NULL, NULL,
				      _("Unstaged changes after reset:"));
		} else {
			int err = reset_index(sha1, reset_type, quiet);
			if (reset_type == KEEP && !err)
				err = reset_index(sha1, MIXED, quiet);
			if (err)
				die(_("Could not reset index file to revision '%s'."), rev);
		}

		if (write_cache(newfd, active_cache, active_nr) ||
		    commit_locked_index(lock))
			die(_("Could not write new index file."));
	}

	if (!pathspec.nr && !unborn) {
		/* Any resets without paths update HEAD to the head being
		 * switched to, saving the previous head in ORIG_HEAD before. */
		update_ref_status = reset_refs(rev, sha1);

		if (reset_type == HARD && !update_ref_status && !quiet)
			print_new_head_line(lookup_commit_reference(sha1));
	}
	if (!pathspec.nr)
		remove_branch_state();

	return update_ref_status;
}