builtin-mailinfo.c: check error status from rewind and ftruncate
[git/spearce.git] / builtin-revert.c
blob151aa6a981832954120359f7c953015525b530d8
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;
42 static const char *me;
44 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
46 static void parse_args(int argc, const char **argv)
48 const char * const * usage_str =
49 action == REVERT ? revert_usage : cherry_pick_usage;
50 unsigned char sha1[20];
51 const char *arg;
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)"),
58 OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
59 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
60 OPT_END(),
63 if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
64 usage_with_options(usage_str, options);
65 arg = argv[0];
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));
76 if (commit->object.type != OBJ_COMMIT)
77 die ("'%s' does not point to a commit", arg);
80 static char *get_oneline(const char *message)
82 char *result;
83 const char *p = message, *abbrev, *eol;
84 int abbrev_len, oneline_len;
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++;
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;
109 static char *get_encoding(const char *message)
111 const char *p = message, *eol;
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;
124 p = eol;
125 if (*p == '\n')
126 p++;
128 return NULL;
131 static struct lock_file msg_file;
132 static int msg_fd;
134 static void add_to_msg(const char *string)
136 int len = strlen(string);
137 if (write_in_full(msg_fd, string, len) < 0)
138 die_errno ("Could not write to MERGE_MSG");
141 static void add_message_to_msg(const char *message)
143 const char *p = message;
144 while (*p && (*p != '\n' || p[1] != '\n'))
145 p++;
147 if (!*p)
148 add_to_msg(sha1_to_hex(commit->object.sha1));
150 p += 2;
151 add_to_msg(p);
152 return;
155 static void set_author_ident_env(const char *message)
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;
164 for (eol = p; *eol && *eol != '\n'; eol++)
165 ; /* do nothing */
166 if (!prefixcmp(p, "author ")) {
167 char *line, *pend, *email, *timestamp;
169 p += 7;
170 line = xmemdupz(p, eol - p);
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)
185 die ("Could not extract author time from %s",
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;
197 p = eol;
198 if (*p == '\n')
199 p++;
201 die ("No author information found in %s",
202 sha1_to_hex(commit->object.sha1));
205 static char *help_msg(const unsigned char *sha1)
207 static char helpbuf[1024];
208 char *msg = getenv("GIT_CHERRY_PICK_HELP");
210 if (msg)
211 return msg;
213 strcpy(helpbuf, " After resolving the conflicts,\n"
214 "mark the corrected paths with 'git add <paths>' "
215 "or 'git rm <paths>' and commit the result.");
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));
223 return helpbuf;
226 static struct tree *empty_tree(void)
228 struct tree *tree = xcalloc(1, sizeof(struct tree));
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;
236 static int revert_or_cherry_pick(int argc, const char **argv)
238 unsigned char head[20];
239 struct commit *base, *next, *parent;
240 int i, index_fd, clean;
241 char *oneline, *reencoded_message = NULL;
242 const char *message, *encoding;
243 char *defmsg = git_pathdup("MERGE_MSG");
244 struct merge_options o;
245 struct tree *result, *next_tree, *base_tree, *head_tree;
246 static struct lock_file index_lock;
248 git_config(git_default_config, NULL);
249 me = action == REVERT ? "revert" : "cherry-pick";
250 setenv(GIT_REFLOG_ACTION, me, 0);
251 parse_args(argc, argv);
253 /* this is copied from the shell script, but it's never triggered... */
254 if (action == REVERT && !no_replay)
255 die("revert is incompatible with replay");
257 if (read_cache() < 0)
258 die("git %s: failed to read the index", me);
259 if (no_commit) {
261 * We do not intend to commit immediately. We just want to
262 * merge the differences in, so let's compute the tree
263 * that represents the "current" state for merge-recursive
264 * to work on.
266 if (write_cache_as_tree(head, 0, NULL))
267 die ("Your index file is unmerged.");
268 } else {
269 if (get_sha1("HEAD", head))
270 die ("You do not have a valid HEAD");
271 if (index_differs_from("HEAD", 0))
272 die ("Dirty index: cannot %s", me);
274 discard_cache();
276 index_fd = hold_locked_index(&index_lock, 1);
278 if (!commit->parents) {
279 if (action == REVERT)
280 die ("Cannot revert a root commit");
281 parent = NULL;
283 else if (commit->parents->next) {
284 /* Reverting or cherry-picking a merge commit */
285 int cnt;
286 struct commit_list *p;
288 if (!mainline)
289 die("Commit %s is a merge but no -m option was given.",
290 sha1_to_hex(commit->object.sha1));
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;
306 if (!(message = commit->buffer))
307 die ("Cannot get commit message for %s",
308 sha1_to_hex(commit->object.sha1));
310 if (parent && parse_commit(parent) < 0)
311 die("%s: cannot parse parent commit %s",
312 me, sha1_to_hex(parent->object.sha1));
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.
321 msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
322 LOCK_DIE_ON_ERROR);
324 encoding = get_encoding(message);
325 if (!encoding)
326 encoding = "UTF-8";
327 if (!git_commit_encoding)
328 git_commit_encoding = "UTF-8";
329 if ((reencoded_message = reencode_string(message,
330 git_commit_encoding, encoding)))
331 message = reencoded_message;
333 oneline = get_oneline(message);
335 if (action == REVERT) {
336 char *oneline_body = strchr(oneline, ' ');
338 base = commit;
339 next = parent;
340 add_to_msg("Revert \"");
341 add_to_msg(oneline_body + 1);
342 add_to_msg("\"\n\nThis reverts commit ");
343 add_to_msg(sha1_to_hex(commit->object.sha1));
345 if (commit->parents->next) {
346 add_to_msg(", reversing\nchanges made to ");
347 add_to_msg(sha1_to_hex(parent->object.sha1));
349 add_to_msg(".\n");
350 } else {
351 base = parent;
352 next = commit;
353 set_author_ident_env(message);
354 add_message_to_msg(message);
355 if (no_replay) {
356 add_to_msg("(cherry picked from commit ");
357 add_to_msg(sha1_to_hex(commit->object.sha1));
358 add_to_msg(")\n");
362 read_cache();
363 init_merge_options(&o);
364 o.branch1 = "HEAD";
365 o.branch2 = oneline;
367 head_tree = parse_tree_indirect(head);
368 next_tree = next ? next->tree : empty_tree();
369 base_tree = base ? base->tree : empty_tree();
371 clean = merge_trees(&o,
372 head_tree,
373 next_tree, base_tree, &result);
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);
379 rollback_lock_file(&index_lock);
381 if (!clean) {
382 add_to_msg("\nConflicts:\n\n");
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++;
394 if (commit_lock_file(&msg_file) < 0)
395 die ("Error wrapping up %s", defmsg);
396 fprintf(stderr, "Automatic %s failed.%s\n",
397 me, help_msg(commit->object.sha1));
398 rerere();
399 exit(1);
401 if (commit_lock_file(&msg_file) < 0)
402 die ("Error wrapping up %s", defmsg);
403 fprintf(stderr, "Finished one %s.\n", me);
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.
414 if (!no_commit) {
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;
426 args[i] = NULL;
427 return execv_git_cmd(args);
429 free(reencoded_message);
430 free(defmsg);
432 return 0;
435 int cmd_revert(int argc, const char **argv, const char *prefix)
437 if (isatty(0))
438 edit = 1;
439 no_replay = 1;
440 action = REVERT;
441 return revert_or_cherry_pick(argc, argv);
444 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
446 no_replay = 0;
447 action = CHERRY_PICK;
448 return revert_or_cherry_pick(argc, argv);