Merge branch 'jc/fix-tree-walk'
[git/git.git] / builtin-reset.c
CommitLineData
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1/*
2 * "git reset" builtin command
3 *
4 * Copyright (c) 2007 Carlos Rica
5 *
6 * Based on git-reset.sh, which is
7 *
8 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
9 */
10#include "cache.h"
11#include "tag.h"
12#include "object.h"
13#include "commit.h"
14#include "run-command.h"
15#include "refs.h"
16#include "diff.h"
17#include "diffcore.h"
18#include "tree.h"
c369e7b8 19#include "branch.h"
5eee6b28 20#include "parse-options.h"
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21#include "unpack-trees.h"
22#include "cache-tree.h"
0e5a7faa 23
5eee6b28 24static const char * const git_reset_usage[] = {
9e8eceab 25 "git reset [--mixed | --soft | --hard | --merge] [-q] [<commit>]",
1b1dd23f 26 "git reset [--mixed] <commit> [--] <paths>...",
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27 NULL
28};
0e5a7faa 29
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30enum reset_type { MIXED, SOFT, HARD, MERGE, NONE };
31static const char *reset_type_names[] = { "mixed", "soft", "hard", "merge", NULL };
32
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33static char *args_to_str(const char **argv)
34{
35 char *buf = NULL;
36 unsigned long len, space = 0, nr = 0;
37
38 for (; *argv; argv++) {
39 len = strlen(*argv);
40 ALLOC_GROW(buf, nr + 1 + len, space);
41 if (nr)
42 buf[nr++] = ' ';
43 memcpy(buf + nr, *argv, len);
44 nr += len;
45 }
46 ALLOC_GROW(buf, nr + 1, space);
47 buf[nr] = '\0';
48
49 return buf;
50}
51
52static inline int is_merge(void)
53{
54 return !access(git_path("MERGE_HEAD"), F_OK);
55}
56
9e8eceab 57static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
0e5a7faa 58{
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59 int nr = 1;
60 int newfd;
61 struct tree_desc desc[2];
62 struct unpack_trees_options opts;
63 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
0e5a7faa 64
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65 memset(&opts, 0, sizeof(opts));
66 opts.head_idx = 1;
67 opts.src_index = &the_index;
68 opts.dst_index = &the_index;
69 opts.fn = oneway_merge;
70 opts.merge = 1;
5aa965a0 71 if (!quiet)
d0f379c2 72 opts.verbose_update = 1;
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73 switch (reset_type) {
74 case MERGE:
d0f379c2 75 opts.update = 1;
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76 break;
77 case HARD:
d0f379c2 78 opts.update = 1;
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79 /* fallthrough */
80 default:
d0f379c2 81 opts.reset = 1;
9e8eceab 82 }
0e5a7faa 83
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84 newfd = hold_locked_index(lock, 1);
85
86 read_cache_unmerged();
87
88 if (!fill_tree_descriptor(desc + nr - 1, sha1))
89 return error("Failed to find tree of %s.", sha1_to_hex(sha1));
90 if (unpack_trees(nr, desc, &opts))
91 return -1;
92 if (write_cache(newfd, active_cache, active_nr) ||
93 commit_locked_index(lock))
94 return error("Could not write new index file.");
95
96 return 0;
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97}
98
99static void print_new_head_line(struct commit *commit)
100{
2efb3b06 101 const char *hex, *body;
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102
103 hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
2efb3b06 104 printf("HEAD is now at %s", hex);
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105 body = strstr(commit->buffer, "\n\n");
106 if (body) {
107 const char *eol;
108 size_t len;
109 body += 2;
110 eol = strchr(body, '\n');
111 len = eol ? eol - body : strlen(body);
112 printf(" %.*s\n", (int) len, body);
113 }
114 else
115 printf("\n");
116}
117
b0320eaf 118static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
0e5a7faa 119{
620a6cd4 120 int result;
0e5a7faa 121
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122 if (!index_lock) {
123 index_lock = xcalloc(1, sizeof(struct lock_file));
124 fd = hold_locked_index(index_lock, 1);
125 }
0e5a7faa 126
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127 if (read_cache() < 0)
128 return error("Could not read index");
b0320eaf 129
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130 result = refresh_index(&the_index, (flags), NULL, NULL,
131 "Unstaged changes after reset:") ? 1 : 0;
620a6cd4 132 if (write_cache(fd, active_cache, active_nr) ||
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133 commit_locked_index(index_lock))
134 return error ("Could not refresh index");
135 return result;
136}
2e7a9785 137
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138static void update_index_from_diff(struct diff_queue_struct *q,
139 struct diff_options *opt, void *data)
140{
141 int i;
620a6cd4 142 int *discard_flag = data;
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143
144 /* do_diff_cache() mangled the index */
145 discard_cache();
620a6cd4 146 *discard_flag = 1;
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147 read_cache();
148
149 for (i = 0; i < q->nr; i++) {
150 struct diff_filespec *one = q->queue[i]->one;
151 if (one->mode) {
152 struct cache_entry *ce;
153 ce = make_cache_entry(one->mode, one->sha1, one->path,
154 0, 0);
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DP
155 if (!ce)
156 die("make_cache_entry failed for path '%s'",
157 one->path);
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158 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
159 ADD_CACHE_OK_TO_REPLACE);
160 } else
161 remove_file_from_cache(one->path);
162 }
163}
164
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165static int interactive_reset(const char *revision, const char **argv,
166 const char *prefix)
167{
168 const char **pathspec = NULL;
169
170 if (*argv)
171 pathspec = get_pathspec(prefix, argv);
172
173 return run_add_interactive(revision, "--patch=reset", pathspec);
174}
175
0e5a7faa 176static int read_from_tree(const char *prefix, const char **argv,
b0320eaf 177 unsigned char *tree_sha1, int refresh_flags)
0e5a7faa 178{
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179 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
180 int index_fd, index_was_discarded = 0;
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181 struct diff_options opt;
182
183 memset(&opt, 0, sizeof(opt));
184 diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
185 opt.output_format = DIFF_FORMAT_CALLBACK;
186 opt.format_callback = update_index_from_diff;
620a6cd4 187 opt.format_callback_data = &index_was_discarded;
0e5a7faa 188
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189 index_fd = hold_locked_index(lock, 1);
190 index_was_discarded = 0;
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191 read_cache();
192 if (do_diff_cache(tree_sha1, &opt))
193 return 1;
194 diffcore_std(&opt);
195 diff_flush(&opt);
03b69c76 196 diff_tree_release_paths(&opt);
2e7a9785 197
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198 if (!index_was_discarded)
199 /* The index is still clobbered from do_diff_cache() */
200 discard_cache();
b0320eaf 201 return update_index_refresh(index_fd, lock, refresh_flags);
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202}
203
204static void prepend_reflog_action(const char *action, char *buf, size_t size)
205{
206 const char *sep = ": ";
207 const char *rla = getenv("GIT_REFLOG_ACTION");
208 if (!rla)
209 rla = sep = "";
210 if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
211 warning("Reflog action message too long: %.*s...", 50, buf);
212}
213
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214int cmd_reset(int argc, const char **argv, const char *prefix)
215{
5eee6b28 216 int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
d002ef4d 217 int patch_mode = 0;
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218 const char *rev = "HEAD";
219 unsigned char sha1[20], *orig = NULL, sha1_orig[20],
220 *old_orig = NULL, sha1_old_orig[20];
221 struct commit *commit;
222 char *reflog_action, msg[1024];
5eee6b28 223 const struct option options[] = {
5d2dcc42 224 OPT__QUIET(&quiet),
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225 OPT_SET_INT(0, "mixed", &reset_type,
226 "reset HEAD and index", MIXED),
227 OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
228 OPT_SET_INT(0, "hard", &reset_type,
229 "reset HEAD, index and working tree", HARD),
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230 OPT_SET_INT(0, "merge", &reset_type,
231 "reset HEAD, index and working tree", MERGE),
d002ef4d 232 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
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233 OPT_END()
234 };
0e5a7faa 235
ef90d6d4 236 git_config(git_default_config, NULL);
0e5a7faa 237
37782920 238 argc = parse_options(argc, argv, prefix, options, git_reset_usage,
5eee6b28 239 PARSE_OPT_KEEP_DASHDASH);
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240 reflog_action = args_to_str(argv);
241 setenv("GIT_REFLOG_ACTION", reflog_action, 0);
242
dfc8f39e
JH
243 /*
244 * Possible arguments are:
245 *
246 * git reset [-opts] <rev> <paths>...
247 * git reset [-opts] <rev> -- <paths>...
248 * git reset [-opts] -- <paths>...
249 * git reset [-opts] <paths>...
250 *
251 * At this point, argv[i] points immediately after [-opts].
252 */
253
254 if (i < argc) {
255 if (!strcmp(argv[i], "--")) {
256 i++; /* reset to HEAD, possibly with paths */
257 } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
258 rev = argv[i];
259 i += 2;
260 }
261 /*
262 * Otherwise, argv[i] could be either <rev> or <paths> and
3ea3c215 263 * has to be unambiguous.
dfc8f39e
JH
264 */
265 else if (!get_sha1(argv[i], sha1)) {
266 /*
267 * Ok, argv[i] looks like a rev; it should not
268 * be a filename.
269 */
270 verify_non_filename(prefix, argv[i]);
271 rev = argv[i++];
272 } else {
273 /* Otherwise we treat this as a filename */
274 verify_filename(prefix, argv[i]);
275 }
276 }
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CR
277
278 if (get_sha1(rev, sha1))
279 die("Failed to resolve '%s' as a valid ref.", rev);
280
281 commit = lookup_commit_reference(sha1);
282 if (!commit)
283 die("Could not parse object '%s'.", rev);
284 hashcpy(sha1, commit->object.sha1);
285
d002ef4d
TR
286 if (patch_mode) {
287 if (reset_type != NONE)
288 die("--patch is incompatible with --{hard,mixed,soft}");
289 return interactive_reset(rev, argv + i, prefix);
290 }
291
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292 /* git reset tree [--] paths... can be used to
293 * load chosen paths from the tree into the index without
294 * affecting the working tree nor HEAD. */
295 if (i < argc) {
296 if (reset_type == MIXED)
297 warning("--mixed option is deprecated with paths.");
298 else if (reset_type != NONE)
299 die("Cannot do %s reset with paths.",
300 reset_type_names[reset_type]);
b0320eaf 301 return read_from_tree(prefix, argv + i, sha1,
43673fdd 302 quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
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CR
303 }
304 if (reset_type == NONE)
305 reset_type = MIXED; /* by default */
306
cd0f0f68
JK
307 if (reset_type == HARD || reset_type == MERGE)
308 setup_work_tree();
49b9362f 309
2b06b0a0
CC
310 if (reset_type == MIXED && is_bare_repository())
311 die("%s reset is not allowed in a bare repository",
312 reset_type_names[reset_type]);
313
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314 /* Soft reset does not touch the index file nor the working tree
315 * at all, but requires them in a good order. Other resets reset
316 * the index file to the tree object we are switching to. */
317 if (reset_type == SOFT) {
94a5728c 318 if (is_merge() || read_cache() < 0 || unmerged_cache())
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319 die("Cannot do a soft reset in the middle of a merge.");
320 }
9e8eceab 321 else if (reset_index_file(sha1, reset_type, quiet))
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CR
322 die("Could not reset index file to revision '%s'.", rev);
323
324 /* Any resets update HEAD to the head being switched to,
325 * saving the previous head in ORIG_HEAD before. */
326 if (!get_sha1("ORIG_HEAD", sha1_old_orig))
327 old_orig = sha1_old_orig;
328 if (!get_sha1("HEAD", sha1_orig)) {
329 orig = sha1_orig;
330 prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
331 update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
332 }
333 else if (old_orig)
eca35a25 334 delete_ref("ORIG_HEAD", old_orig, 0);
0e5a7faa
CR
335 prepend_reflog_action("updating HEAD", msg, sizeof(msg));
336 update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
337
338 switch (reset_type) {
339 case HARD:
521b53e5 340 if (!update_ref_status && !quiet)
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CR
341 print_new_head_line(commit);
342 break;
343 case SOFT: /* Nothing else to do. */
344 break;
345 case MIXED: /* Report what has not been updated. */
b0320eaf 346 update_index_refresh(0, NULL,
43673fdd 347 quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
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348 break;
349 }
350
c369e7b8 351 remove_branch_state();
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352
353 free(reflog_action);
354
355 return update_ref_status;
356}