set_git_dir: fix crash when used with real_path()
[git] / builtin / reset.c
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 #define USE_THE_INDEX_COMPATIBILITY_MACROS
11 #include "builtin.h"
12 #include "config.h"
13 #include "lockfile.h"
14 #include "tag.h"
15 #include "object.h"
16 #include "pretty.h"
17 #include "run-command.h"
18 #include "refs.h"
19 #include "diff.h"
20 #include "diffcore.h"
21 #include "tree.h"
22 #include "branch.h"
23 #include "parse-options.h"
24 #include "unpack-trees.h"
25 #include "cache-tree.h"
26 #include "submodule.h"
27 #include "submodule-config.h"
28
29 #define REFRESH_INDEX_DELAY_WARNING_IN_MS (2 * 1000)
30
31 static const char * const git_reset_usage[] = {
32         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
33         N_("git reset [-q] [<tree-ish>] [--] <pathspec>..."),
34         N_("git reset [-q] [--pathspec-from-file [--pathspec-file-nul]] [<tree-ish>]"),
35         N_("git reset --patch [<tree-ish>] [--] [<pathspec>...]"),
36         NULL
37 };
38
39 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
40 static const char *reset_type_names[] = {
41         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
42 };
43
44 static inline int is_merge(void)
45 {
46         return !access(git_path_merge_head(the_repository), F_OK);
47 }
48
49 static int reset_index(const struct object_id *oid, int reset_type, int quiet)
50 {
51         int i, nr = 0;
52         struct tree_desc desc[2];
53         struct tree *tree;
54         struct unpack_trees_options opts;
55         int ret = -1;
56
57         memset(&opts, 0, sizeof(opts));
58         opts.head_idx = 1;
59         opts.src_index = &the_index;
60         opts.dst_index = &the_index;
61         opts.fn = oneway_merge;
62         opts.merge = 1;
63         if (!quiet)
64                 opts.verbose_update = 1;
65         switch (reset_type) {
66         case KEEP:
67         case MERGE:
68                 opts.update = 1;
69                 break;
70         case HARD:
71                 opts.update = 1;
72                 /* fallthrough */
73         default:
74                 opts.reset = 1;
75         }
76
77         read_cache_unmerged();
78
79         if (reset_type == KEEP) {
80                 struct object_id head_oid;
81                 if (get_oid("HEAD", &head_oid))
82                         return error(_("You do not have a valid HEAD."));
83                 if (!fill_tree_descriptor(the_repository, desc + nr, &head_oid))
84                         return error(_("Failed to find tree of HEAD."));
85                 nr++;
86                 opts.fn = twoway_merge;
87         }
88
89         if (!fill_tree_descriptor(the_repository, desc + nr, oid)) {
90                 error(_("Failed to find tree of %s."), oid_to_hex(oid));
91                 goto out;
92         }
93         nr++;
94
95         if (unpack_trees(nr, desc, &opts))
96                 goto out;
97
98         if (reset_type == MIXED || reset_type == HARD) {
99                 tree = parse_tree_indirect(oid);
100                 prime_cache_tree(the_repository, the_repository->index, tree);
101         }
102
103         ret = 0;
104
105 out:
106         for (i = 0; i < nr; i++)
107                 free((void *)desc[i].buffer);
108         return ret;
109 }
110
111 static void print_new_head_line(struct commit *commit)
112 {
113         struct strbuf buf = STRBUF_INIT;
114
115         printf(_("HEAD is now at %s"),
116                 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
117
118         pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
119         if (buf.len > 0)
120                 printf(" %s", buf.buf);
121         putchar('\n');
122         strbuf_release(&buf);
123 }
124
125 static void update_index_from_diff(struct diff_queue_struct *q,
126                 struct diff_options *opt, void *data)
127 {
128         int i;
129         int intent_to_add = *(int *)data;
130
131         for (i = 0; i < q->nr; i++) {
132                 struct diff_filespec *one = q->queue[i]->one;
133                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
134                 struct cache_entry *ce;
135
136                 if (is_missing && !intent_to_add) {
137                         remove_file_from_cache(one->path);
138                         continue;
139                 }
140
141                 ce = make_cache_entry(&the_index, one->mode, &one->oid, one->path,
142                                       0, 0);
143                 if (!ce)
144                         die(_("make_cache_entry failed for path '%s'"),
145                             one->path);
146                 if (is_missing) {
147                         ce->ce_flags |= CE_INTENT_TO_ADD;
148                         set_object_name_for_intent_to_add_entry(ce);
149                 }
150                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
151         }
152 }
153
154 static int read_from_tree(const struct pathspec *pathspec,
155                           struct object_id *tree_oid,
156                           int intent_to_add)
157 {
158         struct diff_options opt;
159
160         memset(&opt, 0, sizeof(opt));
161         copy_pathspec(&opt.pathspec, pathspec);
162         opt.output_format = DIFF_FORMAT_CALLBACK;
163         opt.format_callback = update_index_from_diff;
164         opt.format_callback_data = &intent_to_add;
165         opt.flags.override_submodule_config = 1;
166         opt.repo = the_repository;
167
168         if (do_diff_cache(tree_oid, &opt))
169                 return 1;
170         diffcore_std(&opt);
171         diff_flush(&opt);
172         clear_pathspec(&opt.pathspec);
173
174         return 0;
175 }
176
177 static void set_reflog_message(struct strbuf *sb, const char *action,
178                                const char *rev)
179 {
180         const char *rla = getenv("GIT_REFLOG_ACTION");
181
182         strbuf_reset(sb);
183         if (rla)
184                 strbuf_addf(sb, "%s: %s", rla, action);
185         else if (rev)
186                 strbuf_addf(sb, "reset: moving to %s", rev);
187         else
188                 strbuf_addf(sb, "reset: %s", action);
189 }
190
191 static void die_if_unmerged_cache(int reset_type)
192 {
193         if (is_merge() || unmerged_cache())
194                 die(_("Cannot do a %s reset in the middle of a merge."),
195                     _(reset_type_names[reset_type]));
196
197 }
198
199 static void parse_args(struct pathspec *pathspec,
200                        const char **argv, const char *prefix,
201                        int patch_mode,
202                        const char **rev_ret)
203 {
204         const char *rev = "HEAD";
205         struct object_id unused;
206         /*
207          * Possible arguments are:
208          *
209          * git reset [-opts] [<rev>]
210          * git reset [-opts] <tree> [<paths>...]
211          * git reset [-opts] <tree> -- [<paths>...]
212          * git reset [-opts] -- [<paths>...]
213          * git reset [-opts] <paths>...
214          *
215          * At this point, argv points immediately after [-opts].
216          */
217
218         if (argv[0]) {
219                 if (!strcmp(argv[0], "--")) {
220                         argv++; /* reset to HEAD, possibly with paths */
221                 } else if (argv[1] && !strcmp(argv[1], "--")) {
222                         rev = argv[0];
223                         argv += 2;
224                 }
225                 /*
226                  * Otherwise, argv[0] could be either <rev> or <paths> and
227                  * has to be unambiguous. If there is a single argument, it
228                  * can not be a tree
229                  */
230                 else if ((!argv[1] && !get_oid_committish(argv[0], &unused)) ||
231                          (argv[1] && !get_oid_treeish(argv[0], &unused))) {
232                         /*
233                          * Ok, argv[0] looks like a commit/tree; it should not
234                          * be a filename.
235                          */
236                         verify_non_filename(prefix, argv[0]);
237                         rev = *argv++;
238                 } else {
239                         /* Otherwise we treat this as a filename */
240                         verify_filename(prefix, argv[0], 1);
241                 }
242         }
243         *rev_ret = rev;
244
245         if (read_cache() < 0)
246                 die(_("index file corrupt"));
247
248         parse_pathspec(pathspec, 0,
249                        PATHSPEC_PREFER_FULL |
250                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
251                        prefix, argv);
252 }
253
254 static int reset_refs(const char *rev, const struct object_id *oid)
255 {
256         int update_ref_status;
257         struct strbuf msg = STRBUF_INIT;
258         struct object_id *orig = NULL, oid_orig,
259                 *old_orig = NULL, oid_old_orig;
260
261         if (!get_oid("ORIG_HEAD", &oid_old_orig))
262                 old_orig = &oid_old_orig;
263         if (!get_oid("HEAD", &oid_orig)) {
264                 orig = &oid_orig;
265                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
266                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
267                            UPDATE_REFS_MSG_ON_ERR);
268         } else if (old_orig)
269                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
270         set_reflog_message(&msg, "updating HEAD", rev);
271         update_ref_status = update_ref(msg.buf, "HEAD", oid, orig, 0,
272                                        UPDATE_REFS_MSG_ON_ERR);
273         strbuf_release(&msg);
274         return update_ref_status;
275 }
276
277 static int git_reset_config(const char *var, const char *value, void *cb)
278 {
279         if (!strcmp(var, "submodule.recurse"))
280                 return git_default_submodule_config(var, value, cb);
281
282         return git_default_config(var, value, cb);
283 }
284
285 int cmd_reset(int argc, const char **argv, const char *prefix)
286 {
287         int reset_type = NONE, update_ref_status = 0, quiet = 0;
288         int patch_mode = 0, pathspec_file_nul = 0, unborn;
289         const char *rev, *pathspec_from_file = NULL;
290         struct object_id oid;
291         struct pathspec pathspec;
292         int intent_to_add = 0;
293         const struct option options[] = {
294                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
295                 OPT_SET_INT(0, "mixed", &reset_type,
296                                                 N_("reset HEAD and index"), MIXED),
297                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
298                 OPT_SET_INT(0, "hard", &reset_type,
299                                 N_("reset HEAD, index and working tree"), HARD),
300                 OPT_SET_INT(0, "merge", &reset_type,
301                                 N_("reset HEAD, index and working tree"), MERGE),
302                 OPT_SET_INT(0, "keep", &reset_type,
303                                 N_("reset HEAD but keep local changes"), KEEP),
304                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
305                             "reset", "control recursive updating of submodules",
306                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
307                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
308                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
309                                 N_("record only the fact that removed paths will be added later")),
310                 OPT_PATHSPEC_FROM_FILE(&pathspec_from_file),
311                 OPT_PATHSPEC_FILE_NUL(&pathspec_file_nul),
312                 OPT_END()
313         };
314
315         git_config(git_reset_config, NULL);
316         git_config_get_bool("reset.quiet", &quiet);
317
318         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
319                                                 PARSE_OPT_KEEP_DASHDASH);
320         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
321
322         if (pathspec_from_file) {
323                 if (patch_mode)
324                         die(_("--pathspec-from-file is incompatible with --patch"));
325
326                 if (pathspec.nr)
327                         die(_("--pathspec-from-file is incompatible with pathspec arguments"));
328
329                 parse_pathspec_file(&pathspec, 0,
330                                     PATHSPEC_PREFER_FULL,
331                                     prefix, pathspec_from_file, pathspec_file_nul);
332         } else if (pathspec_file_nul) {
333                 die(_("--pathspec-file-nul requires --pathspec-from-file"));
334         }
335
336         unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
337         if (unborn) {
338                 /* reset on unborn branch: treat as reset to empty tree */
339                 oidcpy(&oid, the_hash_algo->empty_tree);
340         } else if (!pathspec.nr && !patch_mode) {
341                 struct commit *commit;
342                 if (get_oid_committish(rev, &oid))
343                         die(_("Failed to resolve '%s' as a valid revision."), rev);
344                 commit = lookup_commit_reference(the_repository, &oid);
345                 if (!commit)
346                         die(_("Could not parse object '%s'."), rev);
347                 oidcpy(&oid, &commit->object.oid);
348         } else {
349                 struct tree *tree;
350                 if (get_oid_treeish(rev, &oid))
351                         die(_("Failed to resolve '%s' as a valid tree."), rev);
352                 tree = parse_tree_indirect(&oid);
353                 if (!tree)
354                         die(_("Could not parse object '%s'."), rev);
355                 oidcpy(&oid, &tree->object.oid);
356         }
357
358         if (patch_mode) {
359                 if (reset_type != NONE)
360                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
361                 trace2_cmd_mode("patch-interactive");
362                 return run_add_interactive(rev, "--patch=reset", &pathspec);
363         }
364
365         /* git reset tree [--] paths... can be used to
366          * load chosen paths from the tree into the index without
367          * affecting the working tree nor HEAD. */
368         if (pathspec.nr) {
369                 if (reset_type == MIXED)
370                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
371                 else if (reset_type != NONE)
372                         die(_("Cannot do %s reset with paths."),
373                                         _(reset_type_names[reset_type]));
374         }
375         if (reset_type == NONE)
376                 reset_type = MIXED; /* by default */
377
378         if (pathspec.nr)
379                 trace2_cmd_mode("path");
380         else
381                 trace2_cmd_mode(reset_type_names[reset_type]);
382
383         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
384                 setup_work_tree();
385
386         if (reset_type == MIXED && is_bare_repository())
387                 die(_("%s reset is not allowed in a bare repository"),
388                     _(reset_type_names[reset_type]));
389
390         if (intent_to_add && reset_type != MIXED)
391                 die(_("-N can only be used with --mixed"));
392
393         /* Soft reset does not touch the index file nor the working tree
394          * at all, but requires them in a good order.  Other resets reset
395          * the index file to the tree object we are switching to. */
396         if (reset_type == SOFT || reset_type == KEEP)
397                 die_if_unmerged_cache(reset_type);
398
399         if (reset_type != SOFT) {
400                 struct lock_file lock = LOCK_INIT;
401                 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
402                 if (reset_type == MIXED) {
403                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
404                         if (read_from_tree(&pathspec, &oid, intent_to_add))
405                                 return 1;
406                         the_index.updated_skipworktree = 1;
407                         if (!quiet && get_git_work_tree()) {
408                                 uint64_t t_begin, t_delta_in_ms;
409
410                                 t_begin = getnanotime();
411                                 refresh_index(&the_index, flags, NULL, NULL,
412                                               _("Unstaged changes after reset:"));
413                                 t_delta_in_ms = (getnanotime() - t_begin) / 1000000;
414                                 if (advice_reset_quiet_warning && t_delta_in_ms > REFRESH_INDEX_DELAY_WARNING_IN_MS) {
415                                         printf(_("\nIt took %.2f seconds to enumerate unstaged changes after reset.  You can\n"
416                                                 "use '--quiet' to avoid this.  Set the config setting reset.quiet to true\n"
417                                                 "to make this the default.\n"), t_delta_in_ms / 1000.0);
418                                 }
419                         }
420                 } else {
421                         int err = reset_index(&oid, reset_type, quiet);
422                         if (reset_type == KEEP && !err)
423                                 err = reset_index(&oid, MIXED, quiet);
424                         if (err)
425                                 die(_("Could not reset index file to revision '%s'."), rev);
426                 }
427
428                 if (write_locked_index(&the_index, &lock, COMMIT_LOCK))
429                         die(_("Could not write new index file."));
430         }
431
432         if (!pathspec.nr && !unborn) {
433                 /* Any resets without paths update HEAD to the head being
434                  * switched to, saving the previous head in ORIG_HEAD before. */
435                 update_ref_status = reset_refs(rev, &oid);
436
437                 if (reset_type == HARD && !update_ref_status && !quiet)
438                         print_new_head_line(lookup_commit_reference(the_repository, &oid));
439         }
440         if (!pathspec.nr)
441                 remove_branch_state(the_repository, 0);
442
443         return update_ref_status;
444 }