Merge branch 'wd/rebase-conflict-guide'
[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 #include "builtin.h"
11 #include "config.h"
12 #include "lockfile.h"
13 #include "tag.h"
14 #include "object.h"
15 #include "commit.h"
16 #include "run-command.h"
17 #include "refs.h"
18 #include "diff.h"
19 #include "diffcore.h"
20 #include "tree.h"
21 #include "branch.h"
22 #include "parse-options.h"
23 #include "unpack-trees.h"
24 #include "cache-tree.h"
25 #include "submodule.h"
26 #include "submodule-config.h"
27
28 static const char * const git_reset_usage[] = {
29         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
30         N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
31         N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
32         NULL
33 };
34
35 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
36 static const char *reset_type_names[] = {
37         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
38 };
39
40 static inline int is_merge(void)
41 {
42         return !access(git_path_merge_head(), F_OK);
43 }
44
45 static int reset_index(const struct object_id *oid, int reset_type, int quiet)
46 {
47         int nr = 1;
48         struct tree_desc desc[2];
49         struct tree *tree;
50         struct unpack_trees_options opts;
51
52         memset(&opts, 0, sizeof(opts));
53         opts.head_idx = 1;
54         opts.src_index = &the_index;
55         opts.dst_index = &the_index;
56         opts.fn = oneway_merge;
57         opts.merge = 1;
58         if (!quiet)
59                 opts.verbose_update = 1;
60         switch (reset_type) {
61         case KEEP:
62         case MERGE:
63                 opts.update = 1;
64                 break;
65         case HARD:
66                 opts.update = 1;
67                 /* fallthrough */
68         default:
69                 opts.reset = 1;
70         }
71
72         read_cache_unmerged();
73
74         if (reset_type == KEEP) {
75                 struct object_id head_oid;
76                 if (get_oid("HEAD", &head_oid))
77                         return error(_("You do not have a valid HEAD."));
78                 if (!fill_tree_descriptor(desc, head_oid.hash))
79                         return error(_("Failed to find tree of HEAD."));
80                 nr++;
81                 opts.fn = twoway_merge;
82         }
83
84         if (!fill_tree_descriptor(desc + nr - 1, oid->hash))
85                 return error(_("Failed to find tree of %s."), oid_to_hex(oid));
86         if (unpack_trees(nr, desc, &opts))
87                 return -1;
88
89         if (reset_type == MIXED || reset_type == HARD) {
90                 tree = parse_tree_indirect(oid);
91                 prime_cache_tree(&the_index, tree);
92         }
93
94         return 0;
95 }
96
97 static void print_new_head_line(struct commit *commit)
98 {
99         const char *hex, *body;
100         const char *msg;
101
102         hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
103         printf(_("HEAD is now at %s"), hex);
104         msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
105         body = strstr(msg, "\n\n");
106         if (body) {
107                 const char *eol;
108                 size_t len;
109                 body = skip_blank_lines(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         unuse_commit_buffer(commit, msg);
117 }
118
119 static void update_index_from_diff(struct diff_queue_struct *q,
120                 struct diff_options *opt, void *data)
121 {
122         int i;
123         int intent_to_add = *(int *)data;
124
125         for (i = 0; i < q->nr; i++) {
126                 struct diff_filespec *one = q->queue[i]->one;
127                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
128                 struct cache_entry *ce;
129
130                 if (is_missing && !intent_to_add) {
131                         remove_file_from_cache(one->path);
132                         continue;
133                 }
134
135                 ce = make_cache_entry(one->mode, one->oid.hash, one->path,
136                                       0, 0);
137                 if (!ce)
138                         die(_("make_cache_entry failed for path '%s'"),
139                             one->path);
140                 if (is_missing) {
141                         ce->ce_flags |= CE_INTENT_TO_ADD;
142                         set_object_name_for_intent_to_add_entry(ce);
143                 }
144                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
145         }
146 }
147
148 static int read_from_tree(const struct pathspec *pathspec,
149                           struct object_id *tree_oid,
150                           int intent_to_add)
151 {
152         struct diff_options opt;
153
154         memset(&opt, 0, sizeof(opt));
155         copy_pathspec(&opt.pathspec, pathspec);
156         opt.output_format = DIFF_FORMAT_CALLBACK;
157         opt.format_callback = update_index_from_diff;
158         opt.format_callback_data = &intent_to_add;
159
160         if (do_diff_cache(tree_oid, &opt))
161                 return 1;
162         diffcore_std(&opt);
163         diff_flush(&opt);
164         clear_pathspec(&opt.pathspec);
165
166         return 0;
167 }
168
169 static void set_reflog_message(struct strbuf *sb, const char *action,
170                                const char *rev)
171 {
172         const char *rla = getenv("GIT_REFLOG_ACTION");
173
174         strbuf_reset(sb);
175         if (rla)
176                 strbuf_addf(sb, "%s: %s", rla, action);
177         else if (rev)
178                 strbuf_addf(sb, "reset: moving to %s", rev);
179         else
180                 strbuf_addf(sb, "reset: %s", action);
181 }
182
183 static void die_if_unmerged_cache(int reset_type)
184 {
185         if (is_merge() || unmerged_cache())
186                 die(_("Cannot do a %s reset in the middle of a merge."),
187                     _(reset_type_names[reset_type]));
188
189 }
190
191 static void parse_args(struct pathspec *pathspec,
192                        const char **argv, const char *prefix,
193                        int patch_mode,
194                        const char **rev_ret)
195 {
196         const char *rev = "HEAD";
197         struct object_id unused;
198         /*
199          * Possible arguments are:
200          *
201          * git reset [-opts] [<rev>]
202          * git reset [-opts] <tree> [<paths>...]
203          * git reset [-opts] <tree> -- [<paths>...]
204          * git reset [-opts] -- [<paths>...]
205          * git reset [-opts] <paths>...
206          *
207          * At this point, argv points immediately after [-opts].
208          */
209
210         if (argv[0]) {
211                 if (!strcmp(argv[0], "--")) {
212                         argv++; /* reset to HEAD, possibly with paths */
213                 } else if (argv[1] && !strcmp(argv[1], "--")) {
214                         rev = argv[0];
215                         argv += 2;
216                 }
217                 /*
218                  * Otherwise, argv[0] could be either <rev> or <paths> and
219                  * has to be unambiguous. If there is a single argument, it
220                  * can not be a tree
221                  */
222                 else if ((!argv[1] && !get_oid_committish(argv[0], &unused)) ||
223                          (argv[1] && !get_oid_treeish(argv[0], &unused))) {
224                         /*
225                          * Ok, argv[0] looks like a commit/tree; it should not
226                          * be a filename.
227                          */
228                         verify_non_filename(prefix, argv[0]);
229                         rev = *argv++;
230                 } else {
231                         /* Otherwise we treat this as a filename */
232                         verify_filename(prefix, argv[0], 1);
233                 }
234         }
235         *rev_ret = rev;
236
237         if (read_cache() < 0)
238                 die(_("index file corrupt"));
239
240         parse_pathspec(pathspec, 0,
241                        PATHSPEC_PREFER_FULL |
242                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
243                        prefix, argv);
244 }
245
246 static int reset_refs(const char *rev, const struct object_id *oid)
247 {
248         int update_ref_status;
249         struct strbuf msg = STRBUF_INIT;
250         struct object_id *orig = NULL, oid_orig,
251                 *old_orig = NULL, oid_old_orig;
252
253         if (!get_oid("ORIG_HEAD", &oid_old_orig))
254                 old_orig = &oid_old_orig;
255         if (!get_oid("HEAD", &oid_orig)) {
256                 orig = &oid_orig;
257                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
258                 update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
259                            UPDATE_REFS_MSG_ON_ERR);
260         } else if (old_orig)
261                 delete_ref(NULL, "ORIG_HEAD", old_orig->hash, 0);
262         set_reflog_message(&msg, "updating HEAD", rev);
263         update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
264                                        UPDATE_REFS_MSG_ON_ERR);
265         strbuf_release(&msg);
266         return update_ref_status;
267 }
268
269 static int git_reset_config(const char *var, const char *value, void *cb)
270 {
271         if (!strcmp(var, "submodule.recurse"))
272                 return git_default_submodule_config(var, value, cb);
273
274         return git_default_config(var, value, cb);
275 }
276
277 int cmd_reset(int argc, const char **argv, const char *prefix)
278 {
279         int reset_type = NONE, update_ref_status = 0, quiet = 0;
280         int patch_mode = 0, unborn;
281         const char *rev;
282         struct object_id oid;
283         struct pathspec pathspec;
284         int intent_to_add = 0;
285         const struct option options[] = {
286                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
287                 OPT_SET_INT(0, "mixed", &reset_type,
288                                                 N_("reset HEAD and index"), MIXED),
289                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
290                 OPT_SET_INT(0, "hard", &reset_type,
291                                 N_("reset HEAD, index and working tree"), HARD),
292                 OPT_SET_INT(0, "merge", &reset_type,
293                                 N_("reset HEAD, index and working tree"), MERGE),
294                 OPT_SET_INT(0, "keep", &reset_type,
295                                 N_("reset HEAD but keep local changes"), KEEP),
296                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
297                             "reset", "control recursive updating of submodules",
298                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
299                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
300                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
301                                 N_("record only the fact that removed paths will be added later")),
302                 OPT_END()
303         };
304
305         git_config(git_reset_config, NULL);
306
307         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
308                                                 PARSE_OPT_KEEP_DASHDASH);
309         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
310
311         load_submodule_cache();
312
313         unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
314         if (unborn) {
315                 /* reset on unborn branch: treat as reset to empty tree */
316                 hashcpy(oid.hash, EMPTY_TREE_SHA1_BIN);
317         } else if (!pathspec.nr) {
318                 struct commit *commit;
319                 if (get_oid_committish(rev, &oid))
320                         die(_("Failed to resolve '%s' as a valid revision."), rev);
321                 commit = lookup_commit_reference(&oid);
322                 if (!commit)
323                         die(_("Could not parse object '%s'."), rev);
324                 oidcpy(&oid, &commit->object.oid);
325         } else {
326                 struct tree *tree;
327                 if (get_oid_treeish(rev, &oid))
328                         die(_("Failed to resolve '%s' as a valid tree."), rev);
329                 tree = parse_tree_indirect(&oid);
330                 if (!tree)
331                         die(_("Could not parse object '%s'."), rev);
332                 oidcpy(&oid, &tree->object.oid);
333         }
334
335         if (patch_mode) {
336                 if (reset_type != NONE)
337                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
338                 return run_add_interactive(rev, "--patch=reset", &pathspec);
339         }
340
341         /* git reset tree [--] paths... can be used to
342          * load chosen paths from the tree into the index without
343          * affecting the working tree nor HEAD. */
344         if (pathspec.nr) {
345                 if (reset_type == MIXED)
346                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
347                 else if (reset_type != NONE)
348                         die(_("Cannot do %s reset with paths."),
349                                         _(reset_type_names[reset_type]));
350         }
351         if (reset_type == NONE)
352                 reset_type = MIXED; /* by default */
353
354         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
355                 setup_work_tree();
356
357         if (reset_type == MIXED && is_bare_repository())
358                 die(_("%s reset is not allowed in a bare repository"),
359                     _(reset_type_names[reset_type]));
360
361         if (intent_to_add && reset_type != MIXED)
362                 die(_("-N can only be used with --mixed"));
363
364         /* Soft reset does not touch the index file nor the working tree
365          * at all, but requires them in a good order.  Other resets reset
366          * the index file to the tree object we are switching to. */
367         if (reset_type == SOFT || reset_type == KEEP)
368                 die_if_unmerged_cache(reset_type);
369
370         if (reset_type != SOFT) {
371                 struct lock_file *lock = xcalloc(1, sizeof(*lock));
372                 hold_locked_index(lock, LOCK_DIE_ON_ERROR);
373                 if (reset_type == MIXED) {
374                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
375                         if (read_from_tree(&pathspec, &oid, intent_to_add))
376                                 return 1;
377                         if (get_git_work_tree())
378                                 refresh_index(&the_index, flags, NULL, NULL,
379                                               _("Unstaged changes after reset:"));
380                 } else {
381                         int err = reset_index(&oid, reset_type, quiet);
382                         if (reset_type == KEEP && !err)
383                                 err = reset_index(&oid, MIXED, quiet);
384                         if (err)
385                                 die(_("Could not reset index file to revision '%s'."), rev);
386                 }
387
388                 if (write_locked_index(&the_index, lock, COMMIT_LOCK))
389                         die(_("Could not write new index file."));
390         }
391
392         if (!pathspec.nr && !unborn) {
393                 /* Any resets without paths update HEAD to the head being
394                  * switched to, saving the previous head in ORIG_HEAD before. */
395                 update_ref_status = reset_refs(rev, &oid);
396
397                 if (reset_type == HARD && !update_ref_status && !quiet)
398                         print_new_head_line(lookup_commit_reference(&oid));
399         }
400         if (!pathspec.nr)
401                 remove_branch_state();
402
403         return update_ref_status;
404 }