Git 1.6.6
[git/git.git] / builtin-revert.c
CommitLineData
9509af68
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1#include "cache.h"
2#include "builtin.h"
3#include "object.h"
4#include "commit.h"
5#include "tag.h"
6#include "wt-status.h"
7#include "run-command.h"
8#include "exec_cmd.h"
9#include "utf8.h"
f8103794 10#include "parse-options.h"
45525bd0 11#include "cache-tree.h"
0f2d4476
JK
12#include "diff.h"
13#include "revision.h"
aa1a0111 14#include "rerere.h"
6eb1b437 15#include "merge-recursive.h"
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16
17/*
18 * This implements the builtins revert and cherry-pick.
19 *
20 * Copyright (c) 2007 Johannes E. Schindelin
21 *
22 * Based on git-revert.sh, which is
23 *
24 * Copyright (c) 2005 Linus Torvalds
25 * Copyright (c) 2005 Junio C Hamano
26 */
27
f8103794 28static const char * const revert_usage[] = {
1b1dd23f 29 "git revert [options] <commit-ish>",
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30 NULL
31};
9509af68 32
f8103794 33static const char * const cherry_pick_usage[] = {
1b1dd23f 34 "git cherry-pick [options] <commit-ish>",
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35 NULL
36};
9509af68 37
cfd9c277 38static int edit, no_replay, no_commit, mainline, signoff;
4175e9e3 39static enum { REVERT, CHERRY_PICK } action;
9509af68 40static struct commit *commit;
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41
42static const char *me;
43
44#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
45
f8103794 46static void parse_args(int argc, const char **argv)
9509af68 47{
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48 const char * const * usage_str =
49 action == REVERT ? revert_usage : cherry_pick_usage;
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50 unsigned char sha1[20];
51 const char *arg;
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52 int noop;
53 struct option options[] = {
54 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
55 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
56 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
57 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
cfd9c277 58 OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
02273fdb 59 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
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60 OPT_END(),
61 };
62
37782920 63 if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
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64 usage_with_options(usage_str, options);
65 arg = argv[0];
9509af68 66
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67 if (get_sha1(arg, sha1))
68 die ("Cannot find '%s'", arg);
69 commit = (struct commit *)parse_object(sha1);
70 if (!commit)
71 die ("Could not find %s", sha1_to_hex(sha1));
72 if (commit->object.type == OBJ_TAG) {
73 commit = (struct commit *)
74 deref_tag((struct object *)commit, arg, strlen(arg));
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75 }
76 if (commit->object.type != OBJ_COMMIT)
77 die ("'%s' does not point to a commit", arg);
78}
79
80static char *get_oneline(const char *message)
81{
82 char *result;
83 const char *p = message, *abbrev, *eol;
84 int abbrev_len, oneline_len;
85
86 if (!p)
87 die ("Could not read commit message of %s",
88 sha1_to_hex(commit->object.sha1));
89 while (*p && (*p != '\n' || p[1] != '\n'))
90 p++;
91
92 if (*p) {
93 p += 2;
94 for (eol = p + 1; *eol && *eol != '\n'; eol++)
95 ; /* do nothing */
96 } else
97 eol = p;
98 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
99 abbrev_len = strlen(abbrev);
100 oneline_len = eol - p;
101 result = xmalloc(abbrev_len + 5 + oneline_len);
102 memcpy(result, abbrev, abbrev_len);
103 memcpy(result + abbrev_len, "... ", 4);
104 memcpy(result + abbrev_len + 4, p, oneline_len);
105 result[abbrev_len + 4 + oneline_len] = '\0';
106 return result;
107}
108
52fae7de 109static char *get_encoding(const char *message)
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110{
111 const char *p = message, *eol;
112
113 if (!p)
114 die ("Could not read commit message of %s",
115 sha1_to_hex(commit->object.sha1));
116 while (*p && *p != '\n') {
117 for (eol = p + 1; *eol && *eol != '\n'; eol++)
118 ; /* do nothing */
119 if (!prefixcmp(p, "encoding ")) {
120 char *result = xmalloc(eol - 8 - p);
121 strlcpy(result, p + 9, eol - 8 - p);
122 return result;
123 }
124 p = eol;
125 if (*p == '\n')
126 p++;
127 }
128 return NULL;
129}
130
4175e9e3 131static struct lock_file msg_file;
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132static int msg_fd;
133
134static void add_to_msg(const char *string)
135{
136 int len = strlen(string);
137 if (write_in_full(msg_fd, string, len) < 0)
0721c314 138 die_errno ("Could not write to MERGE_MSG");
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139}
140
141static void add_message_to_msg(const char *message)
142{
143 const char *p = message;
144 while (*p && (*p != '\n' || p[1] != '\n'))
145 p++;
146
147 if (!*p)
148 add_to_msg(sha1_to_hex(commit->object.sha1));
149
150 p += 2;
151 add_to_msg(p);
152 return;
153}
154
155static void set_author_ident_env(const char *message)
156{
157 const char *p = message;
158 if (!p)
159 die ("Could not read commit message of %s",
160 sha1_to_hex(commit->object.sha1));
161 while (*p && *p != '\n') {
162 const char *eol;
163
164 for (eol = p; *eol && *eol != '\n'; eol++)
165 ; /* do nothing */
166 if (!prefixcmp(p, "author ")) {
167 char *line, *pend, *email, *timestamp;
168
169 p += 7;
182af834 170 line = xmemdupz(p, eol - p);
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171 email = strchr(line, '<');
172 if (!email)
173 die ("Could not extract author email from %s",
174 sha1_to_hex(commit->object.sha1));
175 if (email == line)
176 pend = line;
177 else
178 for (pend = email; pend != line + 1 &&
179 isspace(pend[-1]); pend--);
180 ; /* do nothing */
181 *pend = '\0';
182 email++;
183 timestamp = strchr(email, '>');
184 if (!timestamp)
1e5f7add 185 die ("Could not extract author time from %s",
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186 sha1_to_hex(commit->object.sha1));
187 *timestamp = '\0';
188 for (timestamp++; *timestamp && isspace(*timestamp);
189 timestamp++)
190 ; /* do nothing */
191 setenv("GIT_AUTHOR_NAME", line, 1);
192 setenv("GIT_AUTHOR_EMAIL", email, 1);
193 setenv("GIT_AUTHOR_DATE", timestamp, 1);
194 free(line);
195 return;
196 }
197 p = eol;
198 if (*p == '\n')
199 p++;
200 }
201 die ("No author information found in %s",
202 sha1_to_hex(commit->object.sha1));
203}
204
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205static char *help_msg(const unsigned char *sha1)
206{
207 static char helpbuf[1024];
208 char *msg = getenv("GIT_CHERRY_PICK_HELP");
209
210 if (msg)
211 return msg;
212
213 strcpy(helpbuf, " After resolving the conflicts,\n"
214 "mark the corrected paths with 'git add <paths>' "
0d813589 215 "or 'git rm <paths>' and commit the result.");
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216
217 if (action == CHERRY_PICK) {
218 sprintf(helpbuf + strlen(helpbuf),
219 "\nWhen commiting, use the option "
220 "'-c %s' to retain authorship and message.",
221 find_unique_abbrev(sha1, DEFAULT_ABBREV));
222 }
223 return helpbuf;
224}
225
6eb1b437
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226static struct tree *empty_tree(void)
227{
228 struct tree *tree = xcalloc(1, sizeof(struct tree));
229
230 tree->object.parsed = 1;
231 tree->object.type = OBJ_TREE;
232 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
233 return tree;
234}
235
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236static int revert_or_cherry_pick(int argc, const char **argv)
237{
238 unsigned char head[20];
7791ecbc 239 struct commit *base, *next, *parent;
6eb1b437 240 int i, index_fd, clean;
1a8f2741
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241 char *oneline, *reencoded_message = NULL;
242 const char *message, *encoding;
a1a846a1 243 char *defmsg = git_pathdup("MERGE_MSG");
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244 struct merge_options o;
245 struct tree *result, *next_tree, *base_tree, *head_tree;
246 static struct lock_file index_lock;
9509af68 247
ef90d6d4 248 git_config(git_default_config, NULL);
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249 me = action == REVERT ? "revert" : "cherry-pick";
250 setenv(GIT_REFLOG_ACTION, me, 0);
f8103794 251 parse_args(argc, argv);
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252
253 /* this is copied from the shell script, but it's never triggered... */
f8103794 254 if (action == REVERT && !no_replay)
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255 die("revert is incompatible with replay");
256
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257 if (read_cache() < 0)
258 die("git %s: failed to read the index", me);
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259 if (no_commit) {
260 /*
261 * We do not intend to commit immediately. We just want to
71aa2b8f
JH
262 * merge the differences in, so let's compute the tree
263 * that represents the "current" state for merge-recursive
264 * to work on.
9509af68 265 */
45525bd0 266 if (write_cache_as_tree(head, 0, NULL))
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267 die ("Your index file is unmerged.");
268 } else {
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269 if (get_sha1("HEAD", head))
270 die ("You do not have a valid HEAD");
75f3ff2e 271 if (index_differs_from("HEAD", 0))
9509af68 272 die ("Dirty index: cannot %s", me);
9509af68 273 }
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274 discard_cache();
275
276 index_fd = hold_locked_index(&index_lock, 1);
9509af68 277
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278 if (!commit->parents) {
279 if (action == REVERT)
280 die ("Cannot revert a root commit");
281 parent = NULL;
282 }
283 else if (commit->parents->next) {
7791ecbc
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284 /* Reverting or cherry-picking a merge commit */
285 int cnt;
286 struct commit_list *p;
287
288 if (!mainline)
289 die("Commit %s is a merge but no -m option was given.",
290 sha1_to_hex(commit->object.sha1));
291
292 for (cnt = 1, p = commit->parents;
293 cnt != mainline && p;
294 cnt++)
295 p = p->next;
296 if (cnt != mainline || !p)
297 die("Commit %s does not have parent %d",
298 sha1_to_hex(commit->object.sha1), mainline);
299 parent = p->item;
300 } else if (0 < mainline)
301 die("Mainline was specified but commit %s is not a merge.",
302 sha1_to_hex(commit->object.sha1));
303 else
304 parent = commit->parents->item;
305
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306 if (!(message = commit->buffer))
307 die ("Cannot get commit message for %s",
308 sha1_to_hex(commit->object.sha1));
309
6eb1b437
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310 if (parent && parse_commit(parent) < 0)
311 die("%s: cannot parse parent commit %s",
312 me, sha1_to_hex(parent->object.sha1));
313
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314 /*
315 * "commit" is an existing commit. We would want to apply
316 * the difference it introduces since its first parent "prev"
317 * on top of the current HEAD if we are cherry-pick. Or the
318 * reverse of it if we are revert.
319 */
320
acd3b9ec
JH
321 msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
322 LOCK_DIE_ON_ERROR);
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323
324 encoding = get_encoding(message);
325 if (!encoding)
330db18c 326 encoding = "UTF-8";
9509af68 327 if (!git_commit_encoding)
330db18c 328 git_commit_encoding = "UTF-8";
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329 if ((reencoded_message = reencode_string(message,
330 git_commit_encoding, encoding)))
331 message = reencoded_message;
332
333 oneline = get_oneline(message);
334
335 if (action == REVERT) {
e43b0105
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336 char *oneline_body = strchr(oneline, ' ');
337
9509af68 338 base = commit;
7791ecbc 339 next = parent;
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340 add_to_msg("Revert \"");
341 add_to_msg(oneline_body + 1);
342 add_to_msg("\"\n\nThis reverts commit ");
9509af68 343 add_to_msg(sha1_to_hex(commit->object.sha1));
d5be89d8
RR
344
345 if (commit->parents->next) {
346 add_to_msg(", reversing\nchanges made to ");
347 add_to_msg(sha1_to_hex(parent->object.sha1));
348 }
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349 add_to_msg(".\n");
350 } else {
7791ecbc 351 base = parent;
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352 next = commit;
353 set_author_ident_env(message);
354 add_message_to_msg(message);
f8103794 355 if (no_replay) {
0e624044 356 add_to_msg("(cherry picked from commit ");
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357 add_to_msg(sha1_to_hex(commit->object.sha1));
358 add_to_msg(")\n");
359 }
360 }
9509af68 361
6eb1b437
MV
362 read_cache();
363 init_merge_options(&o);
364 o.branch1 = "HEAD";
365 o.branch2 = oneline;
366
367 head_tree = parse_tree_indirect(head);
368 next_tree = next ? next->tree : empty_tree();
369 base_tree = base ? base->tree : empty_tree();
370
371 clean = merge_trees(&o,
372 head_tree,
373 next_tree, base_tree, &result);
374
375 if (active_cache_changed &&
376 (write_cache(index_fd, active_cache, active_nr) ||
377 commit_locked_index(&index_lock)))
378 die("%s: Unable to write new index file", me);
0d66e959 379 rollback_lock_file(&index_lock);
6eb1b437
MV
380
381 if (!clean) {
9509af68 382 add_to_msg("\nConflicts:\n\n");
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383 for (i = 0; i < active_nr;) {
384 struct cache_entry *ce = active_cache[i++];
385 if (ce_stage(ce)) {
386 add_to_msg("\t");
387 add_to_msg(ce->name);
388 add_to_msg("\n");
389 while (i < active_nr && !strcmp(ce->name,
390 active_cache[i]->name))
391 i++;
392 }
393 }
4ed7cd3a 394 if (commit_lock_file(&msg_file) < 0)
abda5227 395 die ("Error wrapping up %s", defmsg);
804c7174
WC
396 fprintf(stderr, "Automatic %s failed.%s\n",
397 me, help_msg(commit->object.sha1));
aa1a0111 398 rerere();
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399 exit(1);
400 }
4ed7cd3a 401 if (commit_lock_file(&msg_file) < 0)
abda5227 402 die ("Error wrapping up %s", defmsg);
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403 fprintf(stderr, "Finished one %s.\n", me);
404
405 /*
406 *
407 * If we are cherry-pick, and if the merge did not result in
408 * hand-editing, we will hit this commit and inherit the original
409 * author date and name.
410 * If we are revert, or if our cherry-pick results in a hand merge,
411 * we had better say that the current user is responsible for that.
412 */
413
414 if (!no_commit) {
cfd9c277
DM
415 /* 6 is max possible length of our args array including NULL */
416 const char *args[6];
417 int i = 0;
418 args[i++] = "commit";
419 args[i++] = "-n";
420 if (signoff)
421 args[i++] = "-s";
422 if (!edit) {
423 args[i++] = "-F";
424 args[i++] = defmsg;
425 }
426 args[i] = NULL;
427 return execv_git_cmd(args);
9509af68 428 }
8e0f7003 429 free(reencoded_message);
d258b258 430 free(defmsg);
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431
432 return 0;
433}
434
435int cmd_revert(int argc, const char **argv, const char *prefix)
436{
437 if (isatty(0))
438 edit = 1;
f8103794 439 no_replay = 1;
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440 action = REVERT;
441 return revert_or_cherry_pick(argc, argv);
442}
443
444int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
445{
f8103794 446 no_replay = 0;
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447 action = CHERRY_PICK;
448 return revert_or_cherry_pick(argc, argv);
449}