Make git-add behave more sensibly in a case-insensitive environment
[git/git.git] / builtin-revert.c
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
15 /*
16 * This implements the builtins revert and cherry-pick.
17 *
18 * Copyright (c) 2007 Johannes E. Schindelin
19 *
20 * Based on git-revert.sh, which is
21 *
22 * Copyright (c) 2005 Linus Torvalds
23 * Copyright (c) 2005 Junio C Hamano
24 */
25
26 static const char * const revert_usage[] = {
27 "git-revert [options] <commit-ish>",
28 NULL
29 };
30
31 static const char * const cherry_pick_usage[] = {
32 "git-cherry-pick [options] <commit-ish>",
33 NULL
34 };
35
36 static int edit, no_replay, no_commit, mainline;
37 static enum { REVERT, CHERRY_PICK } action;
38 static struct commit *commit;
39
40 static const char *me;
41
42 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
43
44 static void parse_args(int argc, const char **argv)
45 {
46 const char * const * usage_str =
47 action == REVERT ? revert_usage : cherry_pick_usage;
48 unsigned char sha1[20];
49 const char *arg;
50 int noop;
51 struct option options[] = {
52 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
53 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
54 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
55 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
56 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
57 OPT_END(),
58 };
59
60 if (parse_options(argc, argv, options, usage_str, 0) != 1)
61 usage_with_options(usage_str, options);
62 arg = argv[0];
63
64 if (get_sha1(arg, sha1))
65 die ("Cannot find '%s'", arg);
66 commit = (struct commit *)parse_object(sha1);
67 if (!commit)
68 die ("Could not find %s", sha1_to_hex(sha1));
69 if (commit->object.type == OBJ_TAG) {
70 commit = (struct commit *)
71 deref_tag((struct object *)commit, arg, strlen(arg));
72 }
73 if (commit->object.type != OBJ_COMMIT)
74 die ("'%s' does not point to a commit", arg);
75 }
76
77 static char *get_oneline(const char *message)
78 {
79 char *result;
80 const char *p = message, *abbrev, *eol;
81 int abbrev_len, oneline_len;
82
83 if (!p)
84 die ("Could not read commit message of %s",
85 sha1_to_hex(commit->object.sha1));
86 while (*p && (*p != '\n' || p[1] != '\n'))
87 p++;
88
89 if (*p) {
90 p += 2;
91 for (eol = p + 1; *eol && *eol != '\n'; eol++)
92 ; /* do nothing */
93 } else
94 eol = p;
95 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
96 abbrev_len = strlen(abbrev);
97 oneline_len = eol - p;
98 result = xmalloc(abbrev_len + 5 + oneline_len);
99 memcpy(result, abbrev, abbrev_len);
100 memcpy(result + abbrev_len, "... ", 4);
101 memcpy(result + abbrev_len + 4, p, oneline_len);
102 result[abbrev_len + 4 + oneline_len] = '\0';
103 return result;
104 }
105
106 static char *get_encoding(const char *message)
107 {
108 const char *p = message, *eol;
109
110 if (!p)
111 die ("Could not read commit message of %s",
112 sha1_to_hex(commit->object.sha1));
113 while (*p && *p != '\n') {
114 for (eol = p + 1; *eol && *eol != '\n'; eol++)
115 ; /* do nothing */
116 if (!prefixcmp(p, "encoding ")) {
117 char *result = xmalloc(eol - 8 - p);
118 strlcpy(result, p + 9, eol - 8 - p);
119 return result;
120 }
121 p = eol;
122 if (*p == '\n')
123 p++;
124 }
125 return NULL;
126 }
127
128 static struct lock_file msg_file;
129 static int msg_fd;
130
131 static void add_to_msg(const char *string)
132 {
133 int len = strlen(string);
134 if (write_in_full(msg_fd, string, len) < 0)
135 die ("Could not write to MERGE_MSG");
136 }
137
138 static void add_message_to_msg(const char *message)
139 {
140 const char *p = message;
141 while (*p && (*p != '\n' || p[1] != '\n'))
142 p++;
143
144 if (!*p)
145 add_to_msg(sha1_to_hex(commit->object.sha1));
146
147 p += 2;
148 add_to_msg(p);
149 return;
150 }
151
152 static void set_author_ident_env(const char *message)
153 {
154 const char *p = message;
155 if (!p)
156 die ("Could not read commit message of %s",
157 sha1_to_hex(commit->object.sha1));
158 while (*p && *p != '\n') {
159 const char *eol;
160
161 for (eol = p; *eol && *eol != '\n'; eol++)
162 ; /* do nothing */
163 if (!prefixcmp(p, "author ")) {
164 char *line, *pend, *email, *timestamp;
165
166 p += 7;
167 line = xmemdupz(p, eol - p);
168 email = strchr(line, '<');
169 if (!email)
170 die ("Could not extract author email from %s",
171 sha1_to_hex(commit->object.sha1));
172 if (email == line)
173 pend = line;
174 else
175 for (pend = email; pend != line + 1 &&
176 isspace(pend[-1]); pend--);
177 ; /* do nothing */
178 *pend = '\0';
179 email++;
180 timestamp = strchr(email, '>');
181 if (!timestamp)
182 die ("Could not extract author email from %s",
183 sha1_to_hex(commit->object.sha1));
184 *timestamp = '\0';
185 for (timestamp++; *timestamp && isspace(*timestamp);
186 timestamp++)
187 ; /* do nothing */
188 setenv("GIT_AUTHOR_NAME", line, 1);
189 setenv("GIT_AUTHOR_EMAIL", email, 1);
190 setenv("GIT_AUTHOR_DATE", timestamp, 1);
191 free(line);
192 return;
193 }
194 p = eol;
195 if (*p == '\n')
196 p++;
197 }
198 die ("No author information found in %s",
199 sha1_to_hex(commit->object.sha1));
200 }
201
202 static int merge_recursive(const char *base_sha1,
203 const char *head_sha1, const char *head_name,
204 const char *next_sha1, const char *next_name)
205 {
206 char buffer[256];
207 const char *argv[6];
208
209 sprintf(buffer, "GITHEAD_%s", head_sha1);
210 setenv(buffer, head_name, 1);
211 sprintf(buffer, "GITHEAD_%s", next_sha1);
212 setenv(buffer, next_name, 1);
213
214 /*
215 * This three way merge is an interesting one. We are at
216 * $head, and would want to apply the change between $commit
217 * and $prev on top of us (when reverting), or the change between
218 * $prev and $commit on top of us (when cherry-picking or replaying).
219 */
220 argv[0] = "merge-recursive";
221 argv[1] = base_sha1;
222 argv[2] = "--";
223 argv[3] = head_sha1;
224 argv[4] = next_sha1;
225 argv[5] = NULL;
226
227 return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
228 }
229
230 static char *help_msg(const unsigned char *sha1)
231 {
232 static char helpbuf[1024];
233 char *msg = getenv("GIT_CHERRY_PICK_HELP");
234
235 if (msg)
236 return msg;
237
238 strcpy(helpbuf, " After resolving the conflicts,\n"
239 "mark the corrected paths with 'git add <paths>' "
240 "or 'git rm <paths>' and commit the result.");
241
242 if (action == CHERRY_PICK) {
243 sprintf(helpbuf + strlen(helpbuf),
244 "\nWhen commiting, use the option "
245 "'-c %s' to retain authorship and message.",
246 find_unique_abbrev(sha1, DEFAULT_ABBREV));
247 }
248 return helpbuf;
249 }
250
251 static int index_is_dirty(void)
252 {
253 struct rev_info rev;
254 init_revisions(&rev, NULL);
255 setup_revisions(0, NULL, &rev, "HEAD");
256 DIFF_OPT_SET(&rev.diffopt, QUIET);
257 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
258 run_diff_index(&rev, 1);
259 return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
260 }
261
262 static int revert_or_cherry_pick(int argc, const char **argv)
263 {
264 unsigned char head[20];
265 struct commit *base, *next, *parent;
266 int i;
267 char *oneline, *reencoded_message = NULL;
268 const char *message, *encoding;
269 const char *defmsg = xstrdup(git_path("MERGE_MSG"));
270
271 git_config(git_default_config);
272 me = action == REVERT ? "revert" : "cherry-pick";
273 setenv(GIT_REFLOG_ACTION, me, 0);
274 parse_args(argc, argv);
275
276 /* this is copied from the shell script, but it's never triggered... */
277 if (action == REVERT && !no_replay)
278 die("revert is incompatible with replay");
279
280 if (no_commit) {
281 /*
282 * We do not intend to commit immediately. We just want to
283 * merge the differences in, so let's compute the tree
284 * that represents the "current" state for merge-recursive
285 * to work on.
286 */
287 if (write_cache_as_tree(head, 0, NULL))
288 die ("Your index file is unmerged.");
289 } else {
290 if (get_sha1("HEAD", head))
291 die ("You do not have a valid HEAD");
292 if (read_cache() < 0)
293 die("could not read the index");
294 if (index_is_dirty())
295 die ("Dirty index: cannot %s", me);
296 discard_cache();
297 }
298
299 if (!commit->parents)
300 die ("Cannot %s a root commit", me);
301 if (commit->parents->next) {
302 /* Reverting or cherry-picking a merge commit */
303 int cnt;
304 struct commit_list *p;
305
306 if (!mainline)
307 die("Commit %s is a merge but no -m option was given.",
308 sha1_to_hex(commit->object.sha1));
309
310 for (cnt = 1, p = commit->parents;
311 cnt != mainline && p;
312 cnt++)
313 p = p->next;
314 if (cnt != mainline || !p)
315 die("Commit %s does not have parent %d",
316 sha1_to_hex(commit->object.sha1), mainline);
317 parent = p->item;
318 } else if (0 < mainline)
319 die("Mainline was specified but commit %s is not a merge.",
320 sha1_to_hex(commit->object.sha1));
321 else
322 parent = commit->parents->item;
323
324 if (!(message = commit->buffer))
325 die ("Cannot get commit message for %s",
326 sha1_to_hex(commit->object.sha1));
327
328 /*
329 * "commit" is an existing commit. We would want to apply
330 * the difference it introduces since its first parent "prev"
331 * on top of the current HEAD if we are cherry-pick. Or the
332 * reverse of it if we are revert.
333 */
334
335 msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
336
337 encoding = get_encoding(message);
338 if (!encoding)
339 encoding = "utf-8";
340 if (!git_commit_encoding)
341 git_commit_encoding = "utf-8";
342 if ((reencoded_message = reencode_string(message,
343 git_commit_encoding, encoding)))
344 message = reencoded_message;
345
346 oneline = get_oneline(message);
347
348 if (action == REVERT) {
349 char *oneline_body = strchr(oneline, ' ');
350
351 base = commit;
352 next = parent;
353 add_to_msg("Revert \"");
354 add_to_msg(oneline_body + 1);
355 add_to_msg("\"\n\nThis reverts commit ");
356 add_to_msg(sha1_to_hex(commit->object.sha1));
357 add_to_msg(".\n");
358 } else {
359 base = parent;
360 next = commit;
361 set_author_ident_env(message);
362 add_message_to_msg(message);
363 if (no_replay) {
364 add_to_msg("(cherry picked from commit ");
365 add_to_msg(sha1_to_hex(commit->object.sha1));
366 add_to_msg(")\n");
367 }
368 }
369
370 if (merge_recursive(sha1_to_hex(base->object.sha1),
371 sha1_to_hex(head), "HEAD",
372 sha1_to_hex(next->object.sha1), oneline) ||
373 write_cache_as_tree(head, 0, NULL)) {
374 add_to_msg("\nConflicts:\n\n");
375 read_cache();
376 for (i = 0; i < active_nr;) {
377 struct cache_entry *ce = active_cache[i++];
378 if (ce_stage(ce)) {
379 add_to_msg("\t");
380 add_to_msg(ce->name);
381 add_to_msg("\n");
382 while (i < active_nr && !strcmp(ce->name,
383 active_cache[i]->name))
384 i++;
385 }
386 }
387 if (commit_lock_file(&msg_file) < 0)
388 die ("Error wrapping up %s", defmsg);
389 fprintf(stderr, "Automatic %s failed.%s\n",
390 me, help_msg(commit->object.sha1));
391 exit(1);
392 }
393 if (commit_lock_file(&msg_file) < 0)
394 die ("Error wrapping up %s", defmsg);
395 fprintf(stderr, "Finished one %s.\n", me);
396
397 /*
398 *
399 * If we are cherry-pick, and if the merge did not result in
400 * hand-editing, we will hit this commit and inherit the original
401 * author date and name.
402 * If we are revert, or if our cherry-pick results in a hand merge,
403 * we had better say that the current user is responsible for that.
404 */
405
406 if (!no_commit) {
407 if (edit)
408 return execl_git_cmd("commit", "-n", NULL);
409 else
410 return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
411 }
412 free(reencoded_message);
413
414 return 0;
415 }
416
417 int cmd_revert(int argc, const char **argv, const char *prefix)
418 {
419 if (isatty(0))
420 edit = 1;
421 no_replay = 1;
422 action = REVERT;
423 return revert_or_cherry_pick(argc, argv);
424 }
425
426 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
427 {
428 no_replay = 0;
429 action = CHERRY_PICK;
430 return revert_or_cherry_pick(argc, argv);
431 }