cvsserver: Use Merged response instead of Update-existing for merged files
[git/git.git] / builtin-revert.c
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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"
10
11/*
12 * This implements the builtins revert and cherry-pick.
13 *
14 * Copyright (c) 2007 Johannes E. Schindelin
15 *
16 * Based on git-revert.sh, which is
17 *
18 * Copyright (c) 2005 Linus Torvalds
19 * Copyright (c) 2005 Junio C Hamano
20 */
21
22static const char *revert_usage = "git-revert [--edit | --no-edit] [-n] <commit-ish>";
23
24static const char *cherry_pick_usage = "git-cherry-pick [--edit] [-n] [-r] [-x] <commit-ish>";
25
26static int edit;
27static int replay;
28enum { REVERT, CHERRY_PICK } action;
29static int no_commit;
30static struct commit *commit;
31static int needed_deref;
32
33static const char *me;
34
35#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
36
37static void parse_options(int argc, const char **argv)
38{
39 const char *usage_str = action == REVERT ?
40 revert_usage : cherry_pick_usage;
41 unsigned char sha1[20];
42 const char *arg;
43 int i;
44
45 if (argc < 2)
46 usage(usage_str);
47
48 for (i = 1; i < argc - 1; i++) {
49 arg = argv[i];
50 if (!strcmp(arg, "-n") || !strcmp(arg, "--no-commit"))
51 no_commit = 1;
52 else if (!strcmp(arg, "-e") || !strcmp(arg, "--edit"))
53 edit = 1;
54 else if (!strcmp(arg, "--no-edit"))
55 edit = 0;
56 else if (!strcmp(arg, "-x") || !strcmp(arg, "--i-really-want-"
57 "to-expose-my-private-commit-object-name"))
58 replay = 0;
59 else if (strcmp(arg, "-r"))
60 usage(usage_str);
61 }
62
63 arg = argv[argc - 1];
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 needed_deref = 1;
73 }
74 if (commit->object.type != OBJ_COMMIT)
75 die ("'%s' does not point to a commit", arg);
76}
77
78static char *get_oneline(const char *message)
79{
80 char *result;
81 const char *p = message, *abbrev, *eol;
82 int abbrev_len, oneline_len;
83
84 if (!p)
85 die ("Could not read commit message of %s",
86 sha1_to_hex(commit->object.sha1));
87 while (*p && (*p != '\n' || p[1] != '\n'))
88 p++;
89
90 if (*p) {
91 p += 2;
92 for (eol = p + 1; *eol && *eol != '\n'; eol++)
93 ; /* do nothing */
94 } else
95 eol = p;
96 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
97 abbrev_len = strlen(abbrev);
98 oneline_len = eol - p;
99 result = xmalloc(abbrev_len + 5 + oneline_len);
100 memcpy(result, abbrev, abbrev_len);
101 memcpy(result + abbrev_len, "... ", 4);
102 memcpy(result + abbrev_len + 4, p, oneline_len);
103 result[abbrev_len + 4 + oneline_len] = '\0';
104 return result;
105}
106
107char *get_encoding(const char *message)
108{
109 const char *p = message, *eol;
110
111 if (!p)
112 die ("Could not read commit message of %s",
113 sha1_to_hex(commit->object.sha1));
114 while (*p && *p != '\n') {
115 for (eol = p + 1; *eol && *eol != '\n'; eol++)
116 ; /* do nothing */
117 if (!prefixcmp(p, "encoding ")) {
118 char *result = xmalloc(eol - 8 - p);
119 strlcpy(result, p + 9, eol - 8 - p);
120 return result;
121 }
122 p = eol;
123 if (*p == '\n')
124 p++;
125 }
126 return NULL;
127}
128
129struct lock_file msg_file;
130static int msg_fd;
131
132static void add_to_msg(const char *string)
133{
134 int len = strlen(string);
135 if (write_in_full(msg_fd, string, len) < 0)
136 die ("Could not write to .msg");
137}
138
139static void add_message_to_msg(const char *message)
140{
141 const char *p = message;
142 while (*p && (*p != '\n' || p[1] != '\n'))
143 p++;
144
145 if (!*p)
146 add_to_msg(sha1_to_hex(commit->object.sha1));
147
148 p += 2;
149 add_to_msg(p);
150 return;
151}
152
153static void set_author_ident_env(const char *message)
154{
155 const char *p = message;
156 if (!p)
157 die ("Could not read commit message of %s",
158 sha1_to_hex(commit->object.sha1));
159 while (*p && *p != '\n') {
160 const char *eol;
161
162 for (eol = p; *eol && *eol != '\n'; eol++)
163 ; /* do nothing */
164 if (!prefixcmp(p, "author ")) {
165 char *line, *pend, *email, *timestamp;
166
167 p += 7;
168 line = xmalloc(eol + 1 - p);
169 memcpy(line, p, eol - p);
170 line[eol - p] = '\0';
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 email 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;
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
205static int merge_recursive(const char *base_sha1,
206 const char *head_sha1, const char *head_name,
207 const char *next_sha1, const char *next_name)
208{
209 char buffer[256];
210
211 sprintf(buffer, "GITHEAD_%s", head_sha1);
212 setenv(buffer, head_name, 1);
213 sprintf(buffer, "GITHEAD_%s", next_sha1);
214 setenv(buffer, next_name, 1);
215
216 /*
217 * This three way merge is an interesting one. We are at
218 * $head, and would want to apply the change between $commit
219 * and $prev on top of us (when reverting), or the change between
220 * $prev and $commit on top of us (when cherry-picking or replaying).
221 */
222
223 return run_command_opt(RUN_COMMAND_NO_STDIN | RUN_GIT_CMD,
224 "merge-recursive", base_sha1, "--",
225 head_sha1, next_sha1, NULL);
226}
227
228static int revert_or_cherry_pick(int argc, const char **argv)
229{
230 unsigned char head[20];
231 struct commit *base, *next;
232 int i;
233 char *oneline, *encoding, *reencoded_message = NULL;
234 const char *message;
235
236 git_config(git_default_config);
237 me = action == REVERT ? "revert" : "cherry-pick";
238 setenv(GIT_REFLOG_ACTION, me, 0);
239 parse_options(argc, argv);
240
241 /* this is copied from the shell script, but it's never triggered... */
242 if (action == REVERT && replay)
243 die("revert is incompatible with replay");
244
245 if (no_commit) {
246 /*
247 * We do not intend to commit immediately. We just want to
248 * merge the differences in.
249 */
250 if (write_tree(head, 0, NULL))
251 die ("Your index file is unmerged.");
252 } else {
253 struct wt_status s;
254
255 if (get_sha1("HEAD", head))
256 die ("You do not have a valid HEAD");
257 wt_status_prepare(&s);
258 if (s.commitable || s.workdir_dirty)
259 die ("Dirty index: cannot %s", me);
260 discard_cache();
261 }
262
263 if (!commit->parents)
264 die ("Cannot %s a root commit", me);
265 if (commit->parents->next)
266 die ("Cannot %s a multi-parent commit.", me);
267 if (!(message = commit->buffer))
268 die ("Cannot get commit message for %s",
269 sha1_to_hex(commit->object.sha1));
270
271 /*
272 * "commit" is an existing commit. We would want to apply
273 * the difference it introduces since its first parent "prev"
274 * on top of the current HEAD if we are cherry-pick. Or the
275 * reverse of it if we are revert.
276 */
277
278 msg_fd = hold_lock_file_for_update(&msg_file, ".msg", 1);
279
280 encoding = get_encoding(message);
281 if (!encoding)
282 encoding = "utf-8";
283 if (!git_commit_encoding)
284 git_commit_encoding = "utf-8";
285 if ((reencoded_message = reencode_string(message,
286 git_commit_encoding, encoding)))
287 message = reencoded_message;
288
289 oneline = get_oneline(message);
290
291 if (action == REVERT) {
292 base = commit;
293 next = commit->parents->item;
294 add_to_msg("Revert ");
295 add_to_msg(find_unique_abbrev(commit->object.sha1,
296 DEFAULT_ABBREV));
297 add_to_msg(oneline);
298 add_to_msg("\nThis reverts commit ");
299 add_to_msg(sha1_to_hex(commit->object.sha1));
300 add_to_msg(".\n");
301 } else {
302 base = commit->parents->item;
303 next = commit;
304 set_author_ident_env(message);
305 add_message_to_msg(message);
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306 if (!replay) {
307 add_to_msg("(cherry picked from commit ");
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308 add_to_msg(sha1_to_hex(commit->object.sha1));
309 add_to_msg(")\n");
310 }
311 }
312 if (needed_deref) {
313 add_to_msg("(original 'git ");
314 add_to_msg(me);
315 add_to_msg("' arguments: ");
316 for (i = 0; i < argc; i++) {
317 if (i)
318 add_to_msg(" ");
319 add_to_msg(argv[i]);
320 }
321 add_to_msg(")\n");
322 }
323
324 if (merge_recursive(sha1_to_hex(base->object.sha1),
325 sha1_to_hex(head), "HEAD",
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326 sha1_to_hex(next->object.sha1), oneline) ||
327 write_tree(head, 0, NULL)) {
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328 const char *target = git_path("MERGE_MSG");
329 add_to_msg("\nConflicts:\n\n");
330 read_cache();
331 for (i = 0; i < active_nr;) {
332 struct cache_entry *ce = active_cache[i++];
333 if (ce_stage(ce)) {
334 add_to_msg("\t");
335 add_to_msg(ce->name);
336 add_to_msg("\n");
337 while (i < active_nr && !strcmp(ce->name,
338 active_cache[i]->name))
339 i++;
340 }
341 }
342 if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
343 die ("Error wrapping up .msg");
344 unlink(target);
345 if (rename(".msg", target))
346 die ("Could not move .msg to %s", target);
347 fprintf(stderr, "Automatic %s failed. "
348 "After resolving the conflicts,\n"
349 "mark the corrected paths with 'git-add <paths>'\n"
350 "and commit the result.\n", me);
351 if (action == CHERRY_PICK) {
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352 fprintf(stderr, "When commiting, use the option "
353 "'-c %s' to retain authorship and message.\n",
354 find_unique_abbrev(commit->object.sha1,
355 DEFAULT_ABBREV));
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356 }
357 exit(1);
358 }
359 if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
360 die ("Error wrapping up .msg");
361 fprintf(stderr, "Finished one %s.\n", me);
362
363 /*
364 *
365 * If we are cherry-pick, and if the merge did not result in
366 * hand-editing, we will hit this commit and inherit the original
367 * author date and name.
368 * If we are revert, or if our cherry-pick results in a hand merge,
369 * we had better say that the current user is responsible for that.
370 */
371
372 if (!no_commit) {
373 if (edit)
374 return execl_git_cmd("commit", "-n", "-F", ".msg",
375 "-e", NULL);
376 else
377 return execl_git_cmd("commit", "-n", "-F", ".msg",
378 NULL);
379 }
380 if (reencoded_message)
381 free(reencoded_message);
382
383 return 0;
384}
385
386int cmd_revert(int argc, const char **argv, const char *prefix)
387{
388 if (isatty(0))
389 edit = 1;
390 action = REVERT;
391 return revert_or_cherry_pick(argc, argv);
392}
393
394int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
395{
396 replay = 1;
397 action = CHERRY_PICK;
398 return revert_or_cherry_pick(argc, argv);
399}