Merge branch 'bk/fix-relative-gitdir-file'
[git/jnareb-git.git] / builtin-revert.c
blob857ca2eefa9719029faf48a143ee4afa846c77a6
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"
10 #include "parse-options.h"
11 #include "cache-tree.h"
12 #include "diff.h"
13 #include "revision.h"
14 #include "rerere.h"
15 #include "merge-recursive.h"
18 * This implements the builtins revert and cherry-pick.
20 * Copyright (c) 2007 Johannes E. Schindelin
22 * Based on git-revert.sh, which is
24 * Copyright (c) 2005 Linus Torvalds
25 * Copyright (c) 2005 Junio C Hamano
28 static const char * const revert_usage[] = {
29 "git revert [options] <commit-ish>",
30 NULL
33 static const char * const cherry_pick_usage[] = {
34 "git cherry-pick [options] <commit-ish>",
35 NULL
38 static int edit, no_replay, no_commit, mainline, signoff;
39 static enum { REVERT, CHERRY_PICK } action;
40 static struct commit *commit;
41 static int allow_rerere_auto;
43 static const char *me;
45 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
47 static void parse_args(int argc, const char **argv)
49 const char * const * usage_str =
50 action == REVERT ? revert_usage : cherry_pick_usage;
51 unsigned char sha1[20];
52 const char *arg;
53 int noop;
54 struct option options[] = {
55 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
56 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
57 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
58 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
59 OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
60 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
61 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
62 OPT_END(),
65 if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
66 usage_with_options(usage_str, options);
67 arg = argv[0];
69 if (get_sha1(arg, sha1))
70 die ("Cannot find '%s'", arg);
71 commit = (struct commit *)parse_object(sha1);
72 if (!commit)
73 die ("Could not find %s", sha1_to_hex(sha1));
74 if (commit->object.type == OBJ_TAG) {
75 commit = (struct commit *)
76 deref_tag((struct object *)commit, arg, strlen(arg));
78 if (commit->object.type != OBJ_COMMIT)
79 die ("'%s' does not point to a commit", arg);
82 static char *get_oneline(const char *message)
84 char *result;
85 const char *p = message, *abbrev, *eol;
86 int abbrev_len, oneline_len;
88 if (!p)
89 die ("Could not read commit message of %s",
90 sha1_to_hex(commit->object.sha1));
91 while (*p && (*p != '\n' || p[1] != '\n'))
92 p++;
94 if (*p) {
95 p += 2;
96 for (eol = p + 1; *eol && *eol != '\n'; eol++)
97 ; /* do nothing */
98 } else
99 eol = p;
100 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
101 abbrev_len = strlen(abbrev);
102 oneline_len = eol - p;
103 result = xmalloc(abbrev_len + 5 + oneline_len);
104 memcpy(result, abbrev, abbrev_len);
105 memcpy(result + abbrev_len, "... ", 4);
106 memcpy(result + abbrev_len + 4, p, oneline_len);
107 result[abbrev_len + 4 + oneline_len] = '\0';
108 return result;
111 static char *get_encoding(const char *message)
113 const char *p = message, *eol;
115 if (!p)
116 die ("Could not read commit message of %s",
117 sha1_to_hex(commit->object.sha1));
118 while (*p && *p != '\n') {
119 for (eol = p + 1; *eol && *eol != '\n'; eol++)
120 ; /* do nothing */
121 if (!prefixcmp(p, "encoding ")) {
122 char *result = xmalloc(eol - 8 - p);
123 strlcpy(result, p + 9, eol - 8 - p);
124 return result;
126 p = eol;
127 if (*p == '\n')
128 p++;
130 return NULL;
133 static struct lock_file msg_file;
134 static int msg_fd;
136 static void add_to_msg(const char *string)
138 int len = strlen(string);
139 if (write_in_full(msg_fd, string, len) < 0)
140 die_errno ("Could not write to MERGE_MSG");
143 static void add_message_to_msg(const char *message)
145 const char *p = message;
146 while (*p && (*p != '\n' || p[1] != '\n'))
147 p++;
149 if (!*p)
150 add_to_msg(sha1_to_hex(commit->object.sha1));
152 p += 2;
153 add_to_msg(p);
154 return;
157 static void set_author_ident_env(const char *message)
159 const char *p = message;
160 if (!p)
161 die ("Could not read commit message of %s",
162 sha1_to_hex(commit->object.sha1));
163 while (*p && *p != '\n') {
164 const char *eol;
166 for (eol = p; *eol && *eol != '\n'; eol++)
167 ; /* do nothing */
168 if (!prefixcmp(p, "author ")) {
169 char *line, *pend, *email, *timestamp;
171 p += 7;
172 line = xmemdupz(p, eol - p);
173 email = strchr(line, '<');
174 if (!email)
175 die ("Could not extract author email from %s",
176 sha1_to_hex(commit->object.sha1));
177 if (email == line)
178 pend = line;
179 else
180 for (pend = email; pend != line + 1 &&
181 isspace(pend[-1]); pend--);
182 ; /* do nothing */
183 *pend = '\0';
184 email++;
185 timestamp = strchr(email, '>');
186 if (!timestamp)
187 die ("Could not extract author time from %s",
188 sha1_to_hex(commit->object.sha1));
189 *timestamp = '\0';
190 for (timestamp++; *timestamp && isspace(*timestamp);
191 timestamp++)
192 ; /* do nothing */
193 setenv("GIT_AUTHOR_NAME", line, 1);
194 setenv("GIT_AUTHOR_EMAIL", email, 1);
195 setenv("GIT_AUTHOR_DATE", timestamp, 1);
196 free(line);
197 return;
199 p = eol;
200 if (*p == '\n')
201 p++;
203 die ("No author information found in %s",
204 sha1_to_hex(commit->object.sha1));
207 static char *help_msg(const unsigned char *sha1)
209 static char helpbuf[1024];
210 char *msg = getenv("GIT_CHERRY_PICK_HELP");
212 if (msg)
213 return msg;
215 strcpy(helpbuf, " After resolving the conflicts,\n"
216 "mark the corrected paths with 'git add <paths>' "
217 "or 'git rm <paths>' and commit the result.");
219 if (action == CHERRY_PICK) {
220 sprintf(helpbuf + strlen(helpbuf),
221 "\nWhen commiting, use the option "
222 "'-c %s' to retain authorship and message.",
223 find_unique_abbrev(sha1, DEFAULT_ABBREV));
225 return helpbuf;
228 static struct tree *empty_tree(void)
230 struct tree *tree = xcalloc(1, sizeof(struct tree));
232 tree->object.parsed = 1;
233 tree->object.type = OBJ_TREE;
234 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
235 return tree;
238 static int revert_or_cherry_pick(int argc, const char **argv)
240 unsigned char head[20];
241 struct commit *base, *next, *parent;
242 int i, index_fd, clean;
243 char *oneline, *reencoded_message = NULL;
244 const char *message, *encoding;
245 char *defmsg = git_pathdup("MERGE_MSG");
246 struct merge_options o;
247 struct tree *result, *next_tree, *base_tree, *head_tree;
248 static struct lock_file index_lock;
250 git_config(git_default_config, NULL);
251 me = action == REVERT ? "revert" : "cherry-pick";
252 setenv(GIT_REFLOG_ACTION, me, 0);
253 parse_args(argc, argv);
255 /* this is copied from the shell script, but it's never triggered... */
256 if (action == REVERT && !no_replay)
257 die("revert is incompatible with replay");
259 if (read_cache() < 0)
260 die("git %s: failed to read the index", me);
261 if (no_commit) {
263 * We do not intend to commit immediately. We just want to
264 * merge the differences in, so let's compute the tree
265 * that represents the "current" state for merge-recursive
266 * to work on.
268 if (write_cache_as_tree(head, 0, NULL))
269 die ("Your index file is unmerged.");
270 } else {
271 if (get_sha1("HEAD", head))
272 die ("You do not have a valid HEAD");
273 if (index_differs_from("HEAD", 0))
274 die ("Dirty index: cannot %s", me);
276 discard_cache();
278 index_fd = hold_locked_index(&index_lock, 1);
280 if (!commit->parents) {
281 if (action == REVERT)
282 die ("Cannot revert a root commit");
283 parent = NULL;
285 else if (commit->parents->next) {
286 /* Reverting or cherry-picking a merge commit */
287 int cnt;
288 struct commit_list *p;
290 if (!mainline)
291 die("Commit %s is a merge but no -m option was given.",
292 sha1_to_hex(commit->object.sha1));
294 for (cnt = 1, p = commit->parents;
295 cnt != mainline && p;
296 cnt++)
297 p = p->next;
298 if (cnt != mainline || !p)
299 die("Commit %s does not have parent %d",
300 sha1_to_hex(commit->object.sha1), mainline);
301 parent = p->item;
302 } else if (0 < mainline)
303 die("Mainline was specified but commit %s is not a merge.",
304 sha1_to_hex(commit->object.sha1));
305 else
306 parent = commit->parents->item;
308 if (!(message = commit->buffer))
309 die ("Cannot get commit message for %s",
310 sha1_to_hex(commit->object.sha1));
312 if (parent && parse_commit(parent) < 0)
313 die("%s: cannot parse parent commit %s",
314 me, sha1_to_hex(parent->object.sha1));
317 * "commit" is an existing commit. We would want to apply
318 * the difference it introduces since its first parent "prev"
319 * on top of the current HEAD if we are cherry-pick. Or the
320 * reverse of it if we are revert.
323 msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
324 LOCK_DIE_ON_ERROR);
326 encoding = get_encoding(message);
327 if (!encoding)
328 encoding = "UTF-8";
329 if (!git_commit_encoding)
330 git_commit_encoding = "UTF-8";
331 if ((reencoded_message = reencode_string(message,
332 git_commit_encoding, encoding)))
333 message = reencoded_message;
335 oneline = get_oneline(message);
337 if (action == REVERT) {
338 char *oneline_body = strchr(oneline, ' ');
340 base = commit;
341 next = parent;
342 add_to_msg("Revert \"");
343 add_to_msg(oneline_body + 1);
344 add_to_msg("\"\n\nThis reverts commit ");
345 add_to_msg(sha1_to_hex(commit->object.sha1));
347 if (commit->parents->next) {
348 add_to_msg(", reversing\nchanges made to ");
349 add_to_msg(sha1_to_hex(parent->object.sha1));
351 add_to_msg(".\n");
352 } else {
353 base = parent;
354 next = commit;
355 set_author_ident_env(message);
356 add_message_to_msg(message);
357 if (no_replay) {
358 add_to_msg("(cherry picked from commit ");
359 add_to_msg(sha1_to_hex(commit->object.sha1));
360 add_to_msg(")\n");
364 read_cache();
365 init_merge_options(&o);
366 o.branch1 = "HEAD";
367 o.branch2 = oneline;
369 head_tree = parse_tree_indirect(head);
370 next_tree = next ? next->tree : empty_tree();
371 base_tree = base ? base->tree : empty_tree();
373 clean = merge_trees(&o,
374 head_tree,
375 next_tree, base_tree, &result);
377 if (active_cache_changed &&
378 (write_cache(index_fd, active_cache, active_nr) ||
379 commit_locked_index(&index_lock)))
380 die("%s: Unable to write new index file", me);
381 rollback_lock_file(&index_lock);
383 if (!clean) {
384 add_to_msg("\nConflicts:\n\n");
385 for (i = 0; i < active_nr;) {
386 struct cache_entry *ce = active_cache[i++];
387 if (ce_stage(ce)) {
388 add_to_msg("\t");
389 add_to_msg(ce->name);
390 add_to_msg("\n");
391 while (i < active_nr && !strcmp(ce->name,
392 active_cache[i]->name))
393 i++;
396 if (commit_lock_file(&msg_file) < 0)
397 die ("Error wrapping up %s", defmsg);
398 fprintf(stderr, "Automatic %s failed.%s\n",
399 me, help_msg(commit->object.sha1));
400 rerere(allow_rerere_auto);
401 exit(1);
403 if (commit_lock_file(&msg_file) < 0)
404 die ("Error wrapping up %s", defmsg);
405 fprintf(stderr, "Finished one %s.\n", me);
409 * If we are cherry-pick, and if the merge did not result in
410 * hand-editing, we will hit this commit and inherit the original
411 * author date and name.
412 * If we are revert, or if our cherry-pick results in a hand merge,
413 * we had better say that the current user is responsible for that.
416 if (!no_commit) {
417 /* 6 is max possible length of our args array including NULL */
418 const char *args[6];
419 int i = 0;
420 args[i++] = "commit";
421 args[i++] = "-n";
422 if (signoff)
423 args[i++] = "-s";
424 if (!edit) {
425 args[i++] = "-F";
426 args[i++] = defmsg;
428 args[i] = NULL;
429 return execv_git_cmd(args);
431 free(reencoded_message);
432 free(defmsg);
434 return 0;
437 int cmd_revert(int argc, const char **argv, const char *prefix)
439 if (isatty(0))
440 edit = 1;
441 no_replay = 1;
442 action = REVERT;
443 return revert_or_cherry_pick(argc, argv);
446 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
448 no_replay = 0;
449 action = CHERRY_PICK;
450 return revert_or_cherry_pick(argc, argv);