Merge branch 'ss/mailsplit'
[git/git.git] / builtin-revert.c
CommitLineData
9509af68
JS
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"
9509af68
JS
11
12/*
13 * This implements the builtins revert and cherry-pick.
14 *
15 * Copyright (c) 2007 Johannes E. Schindelin
16 *
17 * Based on git-revert.sh, which is
18 *
19 * Copyright (c) 2005 Linus Torvalds
20 * Copyright (c) 2005 Junio C Hamano
21 */
22
f8103794
PH
23static const char * const revert_usage[] = {
24 "git-revert [options] <commit-ish>",
25 NULL
26};
9509af68 27
f8103794
PH
28static const char * const cherry_pick_usage[] = {
29 "git-cherry-pick [options] <commit-ish>",
30 NULL
31};
9509af68 32
f8103794 33static int edit, no_replay, no_commit, needed_deref;
4175e9e3 34static enum { REVERT, CHERRY_PICK } action;
9509af68 35static struct commit *commit;
9509af68
JS
36
37static const char *me;
38
39#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
40
f8103794 41static void parse_args(int argc, const char **argv)
9509af68 42{
f8103794
PH
43 const char * const * usage_str =
44 action == REVERT ? revert_usage : cherry_pick_usage;
9509af68
JS
45 unsigned char sha1[20];
46 const char *arg;
f8103794
PH
47 int noop;
48 struct option options[] = {
49 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
50 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
51 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
52 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
53 OPT_END(),
54 };
55
56 if (parse_options(argc, argv, options, usage_str, 0) != 1)
57 usage_with_options(usage_str, options);
58 arg = argv[0];
9509af68
JS
59 if (get_sha1(arg, sha1))
60 die ("Cannot find '%s'", arg);
61 commit = (struct commit *)parse_object(sha1);
62 if (!commit)
63 die ("Could not find %s", sha1_to_hex(sha1));
64 if (commit->object.type == OBJ_TAG) {
65 commit = (struct commit *)
66 deref_tag((struct object *)commit, arg, strlen(arg));
67 needed_deref = 1;
68 }
69 if (commit->object.type != OBJ_COMMIT)
70 die ("'%s' does not point to a commit", arg);
71}
72
73static char *get_oneline(const char *message)
74{
75 char *result;
76 const char *p = message, *abbrev, *eol;
77 int abbrev_len, oneline_len;
78
79 if (!p)
80 die ("Could not read commit message of %s",
81 sha1_to_hex(commit->object.sha1));
82 while (*p && (*p != '\n' || p[1] != '\n'))
83 p++;
84
85 if (*p) {
86 p += 2;
87 for (eol = p + 1; *eol && *eol != '\n'; eol++)
88 ; /* do nothing */
89 } else
90 eol = p;
91 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
92 abbrev_len = strlen(abbrev);
93 oneline_len = eol - p;
94 result = xmalloc(abbrev_len + 5 + oneline_len);
95 memcpy(result, abbrev, abbrev_len);
96 memcpy(result + abbrev_len, "... ", 4);
97 memcpy(result + abbrev_len + 4, p, oneline_len);
98 result[abbrev_len + 4 + oneline_len] = '\0';
99 return result;
100}
101
52fae7de 102static char *get_encoding(const char *message)
9509af68
JS
103{
104 const char *p = message, *eol;
105
106 if (!p)
107 die ("Could not read commit message of %s",
108 sha1_to_hex(commit->object.sha1));
109 while (*p && *p != '\n') {
110 for (eol = p + 1; *eol && *eol != '\n'; eol++)
111 ; /* do nothing */
112 if (!prefixcmp(p, "encoding ")) {
113 char *result = xmalloc(eol - 8 - p);
114 strlcpy(result, p + 9, eol - 8 - p);
115 return result;
116 }
117 p = eol;
118 if (*p == '\n')
119 p++;
120 }
121 return NULL;
122}
123
4175e9e3 124static struct lock_file msg_file;
9509af68
JS
125static int msg_fd;
126
127static void add_to_msg(const char *string)
128{
129 int len = strlen(string);
130 if (write_in_full(msg_fd, string, len) < 0)
1dcb3b64 131 die ("Could not write to MERGE_MSG");
9509af68
JS
132}
133
134static void add_message_to_msg(const char *message)
135{
136 const char *p = message;
137 while (*p && (*p != '\n' || p[1] != '\n'))
138 p++;
139
140 if (!*p)
141 add_to_msg(sha1_to_hex(commit->object.sha1));
142
143 p += 2;
144 add_to_msg(p);
145 return;
146}
147
148static void set_author_ident_env(const char *message)
149{
150 const char *p = message;
151 if (!p)
152 die ("Could not read commit message of %s",
153 sha1_to_hex(commit->object.sha1));
154 while (*p && *p != '\n') {
155 const char *eol;
156
157 for (eol = p; *eol && *eol != '\n'; eol++)
158 ; /* do nothing */
159 if (!prefixcmp(p, "author ")) {
160 char *line, *pend, *email, *timestamp;
161
162 p += 7;
182af834 163 line = xmemdupz(p, eol - p);
9509af68
JS
164 email = strchr(line, '<');
165 if (!email)
166 die ("Could not extract author email from %s",
167 sha1_to_hex(commit->object.sha1));
168 if (email == line)
169 pend = line;
170 else
171 for (pend = email; pend != line + 1 &&
172 isspace(pend[-1]); pend--);
173 ; /* do nothing */
174 *pend = '\0';
175 email++;
176 timestamp = strchr(email, '>');
177 if (!timestamp)
178 die ("Could not extract author email from %s",
179 sha1_to_hex(commit->object.sha1));
180 *timestamp = '\0';
181 for (timestamp++; *timestamp && isspace(*timestamp);
182 timestamp++)
183 ; /* do nothing */
184 setenv("GIT_AUTHOR_NAME", line, 1);
185 setenv("GIT_AUTHOR_EMAIL", email, 1);
186 setenv("GIT_AUTHOR_DATE", timestamp, 1);
187 free(line);
188 return;
189 }
190 p = eol;
191 if (*p == '\n')
192 p++;
193 }
194 die ("No author information found in %s",
195 sha1_to_hex(commit->object.sha1));
196}
197
198static int merge_recursive(const char *base_sha1,
199 const char *head_sha1, const char *head_name,
200 const char *next_sha1, const char *next_name)
201{
202 char buffer[256];
497bdc88 203 const char *argv[6];
9509af68
JS
204
205 sprintf(buffer, "GITHEAD_%s", head_sha1);
206 setenv(buffer, head_name, 1);
207 sprintf(buffer, "GITHEAD_%s", next_sha1);
208 setenv(buffer, next_name, 1);
209
210 /*
211 * This three way merge is an interesting one. We are at
212 * $head, and would want to apply the change between $commit
213 * and $prev on top of us (when reverting), or the change between
214 * $prev and $commit on top of us (when cherry-picking or replaying).
215 */
497bdc88
SP
216 argv[0] = "merge-recursive";
217 argv[1] = base_sha1;
218 argv[2] = "--";
219 argv[3] = head_sha1;
220 argv[4] = next_sha1;
221 argv[5] = NULL;
222
223 return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
9509af68
JS
224}
225
226static int revert_or_cherry_pick(int argc, const char **argv)
227{
228 unsigned char head[20];
229 struct commit *base, *next;
230 int i;
1a8f2741
SP
231 char *oneline, *reencoded_message = NULL;
232 const char *message, *encoding;
abda5227 233 const char *defmsg = xstrdup(git_path("MERGE_MSG"));
9509af68
JS
234
235 git_config(git_default_config);
236 me = action == REVERT ? "revert" : "cherry-pick";
237 setenv(GIT_REFLOG_ACTION, me, 0);
f8103794 238 parse_args(argc, argv);
9509af68
JS
239
240 /* this is copied from the shell script, but it's never triggered... */
f8103794 241 if (action == REVERT && !no_replay)
9509af68
JS
242 die("revert is incompatible with replay");
243
244 if (no_commit) {
245 /*
246 * We do not intend to commit immediately. We just want to
247 * merge the differences in.
248 */
249 if (write_tree(head, 0, NULL))
250 die ("Your index file is unmerged.");
251 } else {
252 struct wt_status s;
253
254 if (get_sha1("HEAD", head))
255 die ("You do not have a valid HEAD");
256 wt_status_prepare(&s);
257 if (s.commitable || s.workdir_dirty)
258 die ("Dirty index: cannot %s", me);
259 discard_cache();
260 }
261
262 if (!commit->parents)
263 die ("Cannot %s a root commit", me);
264 if (commit->parents->next)
265 die ("Cannot %s a multi-parent commit.", me);
266 if (!(message = commit->buffer))
267 die ("Cannot get commit message for %s",
268 sha1_to_hex(commit->object.sha1));
269
270 /*
271 * "commit" is an existing commit. We would want to apply
272 * the difference it introduces since its first parent "prev"
273 * on top of the current HEAD if we are cherry-pick. Or the
274 * reverse of it if we are revert.
275 */
276
abda5227 277 msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
9509af68
JS
278
279 encoding = get_encoding(message);
280 if (!encoding)
281 encoding = "utf-8";
282 if (!git_commit_encoding)
283 git_commit_encoding = "utf-8";
284 if ((reencoded_message = reencode_string(message,
285 git_commit_encoding, encoding)))
286 message = reencoded_message;
287
288 oneline = get_oneline(message);
289
290 if (action == REVERT) {
e43b0105
JS
291 char *oneline_body = strchr(oneline, ' ');
292
9509af68
JS
293 base = commit;
294 next = commit->parents->item;
e43b0105
JS
295 add_to_msg("Revert \"");
296 add_to_msg(oneline_body + 1);
297 add_to_msg("\"\n\nThis reverts commit ");
9509af68
JS
298 add_to_msg(sha1_to_hex(commit->object.sha1));
299 add_to_msg(".\n");
300 } else {
301 base = commit->parents->item;
302 next = commit;
303 set_author_ident_env(message);
304 add_message_to_msg(message);
f8103794 305 if (no_replay) {
0e624044 306 add_to_msg("(cherry picked from commit ");
9509af68
JS
307 add_to_msg(sha1_to_hex(commit->object.sha1));
308 add_to_msg(")\n");
309 }
310 }
311 if (needed_deref) {
312 add_to_msg("(original 'git ");
313 add_to_msg(me);
314 add_to_msg("' arguments: ");
315 for (i = 0; i < argc; i++) {
316 if (i)
317 add_to_msg(" ");
318 add_to_msg(argv[i]);
319 }
320 add_to_msg(")\n");
321 }
322
323 if (merge_recursive(sha1_to_hex(base->object.sha1),
324 sha1_to_hex(head), "HEAD",
f52463a5
JS
325 sha1_to_hex(next->object.sha1), oneline) ||
326 write_tree(head, 0, NULL)) {
9509af68
JS
327 add_to_msg("\nConflicts:\n\n");
328 read_cache();
329 for (i = 0; i < active_nr;) {
330 struct cache_entry *ce = active_cache[i++];
331 if (ce_stage(ce)) {
332 add_to_msg("\t");
333 add_to_msg(ce->name);
334 add_to_msg("\n");
335 while (i < active_nr && !strcmp(ce->name,
336 active_cache[i]->name))
337 i++;
338 }
339 }
340 if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
abda5227 341 die ("Error wrapping up %s", defmsg);
9509af68
JS
342 fprintf(stderr, "Automatic %s failed. "
343 "After resolving the conflicts,\n"
04bd8e5f 344 "mark the corrected paths with 'git add <paths>' "
9509af68
JS
345 "and commit the result.\n", me);
346 if (action == CHERRY_PICK) {
f52463a5
JS
347 fprintf(stderr, "When commiting, use the option "
348 "'-c %s' to retain authorship and message.\n",
349 find_unique_abbrev(commit->object.sha1,
350 DEFAULT_ABBREV));
9509af68
JS
351 }
352 exit(1);
353 }
354 if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
abda5227 355 die ("Error wrapping up %s", defmsg);
9509af68
JS
356 fprintf(stderr, "Finished one %s.\n", me);
357
358 /*
359 *
360 * If we are cherry-pick, and if the merge did not result in
361 * hand-editing, we will hit this commit and inherit the original
362 * author date and name.
363 * If we are revert, or if our cherry-pick results in a hand merge,
364 * we had better say that the current user is responsible for that.
365 */
366
367 if (!no_commit) {
368 if (edit)
abda5227 369 return execl_git_cmd("commit", "-n", NULL);
9509af68 370 else
abda5227 371 return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
9509af68
JS
372 }
373 if (reencoded_message)
374 free(reencoded_message);
375
376 return 0;
377}
378
379int cmd_revert(int argc, const char **argv, const char *prefix)
380{
381 if (isatty(0))
382 edit = 1;
f8103794 383 no_replay = 1;
9509af68
JS
384 action = REVERT;
385 return revert_or_cherry_pick(argc, argv);
386}
387
388int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
389{
f8103794 390 no_replay = 0;
9509af68
JS
391 action = CHERRY_PICK;
392 return revert_or_cherry_pick(argc, argv);
393}