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Commit | Line | Data |
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16da134b JS |
1 | #include <signal.h> |
2 | #include <sys/time.h> | |
3 | #include "cache.h" | |
4 | #include "tree.h" | |
5 | #include "tree-walk.h" | |
076b0adc | 6 | #include "cache-tree.h" |
16da134b JS |
7 | #include "unpack-trees.h" |
8 | ||
076b0adc JS |
9 | #define DBRT_DEBUG 1 |
10 | ||
16da134b JS |
11 | struct tree_entry_list { |
12 | struct tree_entry_list *next; | |
13 | unsigned directory : 1; | |
14 | unsigned executable : 1; | |
15 | unsigned symlink : 1; | |
16 | unsigned int mode; | |
17 | const char *name; | |
18 | const unsigned char *sha1; | |
19 | }; | |
20 | ||
21 | static struct tree_entry_list *create_tree_entry_list(struct tree *tree) | |
22 | { | |
23 | struct tree_desc desc; | |
24 | struct name_entry one; | |
25 | struct tree_entry_list *ret = NULL; | |
26 | struct tree_entry_list **list_p = &ret; | |
27 | ||
076b0adc JS |
28 | if (!tree->object.parsed) |
29 | parse_tree(tree); | |
30 | ||
16da134b JS |
31 | desc.buf = tree->buffer; |
32 | desc.size = tree->size; | |
33 | ||
34 | while (tree_entry(&desc, &one)) { | |
35 | struct tree_entry_list *entry; | |
36 | ||
37 | entry = xmalloc(sizeof(struct tree_entry_list)); | |
38 | entry->name = one.path; | |
39 | entry->sha1 = one.sha1; | |
40 | entry->mode = one.mode; | |
41 | entry->directory = S_ISDIR(one.mode) != 0; | |
42 | entry->executable = (one.mode & S_IXUSR) != 0; | |
43 | entry->symlink = S_ISLNK(one.mode) != 0; | |
44 | entry->next = NULL; | |
45 | ||
46 | *list_p = entry; | |
47 | list_p = &entry->next; | |
48 | } | |
49 | return ret; | |
50 | } | |
51 | ||
52 | static int entcmp(const char *name1, int dir1, const char *name2, int dir2) | |
53 | { | |
54 | int len1 = strlen(name1); | |
55 | int len2 = strlen(name2); | |
56 | int len = len1 < len2 ? len1 : len2; | |
57 | int ret = memcmp(name1, name2, len); | |
58 | unsigned char c1, c2; | |
59 | if (ret) | |
60 | return ret; | |
61 | c1 = name1[len]; | |
62 | c2 = name2[len]; | |
63 | if (!c1 && dir1) | |
64 | c1 = '/'; | |
65 | if (!c2 && dir2) | |
66 | c2 = '/'; | |
67 | ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; | |
68 | if (c1 && c2 && !ret) | |
69 | ret = len1 - len2; | |
70 | return ret; | |
71 | } | |
72 | ||
73 | static int unpack_trees_rec(struct tree_entry_list **posns, int len, | |
74 | const char *base, struct unpack_trees_options *o, | |
75 | int *indpos, | |
76 | struct tree_entry_list *df_conflict_list) | |
77 | { | |
78 | int baselen = strlen(base); | |
79 | int src_size = len + 1; | |
80 | do { | |
81 | int i; | |
82 | const char *first; | |
83 | int firstdir = 0; | |
84 | int pathlen; | |
85 | unsigned ce_size; | |
86 | struct tree_entry_list **subposns; | |
87 | struct cache_entry **src; | |
88 | int any_files = 0; | |
89 | int any_dirs = 0; | |
90 | char *cache_name; | |
91 | int ce_stage; | |
92 | ||
93 | /* Find the first name in the input. */ | |
94 | ||
95 | first = NULL; | |
96 | cache_name = NULL; | |
97 | ||
98 | /* Check the cache */ | |
99 | if (o->merge && *indpos < active_nr) { | |
100 | /* This is a bit tricky: */ | |
101 | /* If the index has a subdirectory (with | |
102 | * contents) as the first name, it'll get a | |
103 | * filename like "foo/bar". But that's after | |
104 | * "foo", so the entry in trees will get | |
105 | * handled first, at which point we'll go into | |
106 | * "foo", and deal with "bar" from the index, | |
107 | * because the base will be "foo/". The only | |
108 | * way we can actually have "foo/bar" first of | |
109 | * all the things is if the trees don't | |
110 | * contain "foo" at all, in which case we'll | |
111 | * handle "foo/bar" without going into the | |
112 | * directory, but that's fine (and will return | |
113 | * an error anyway, with the added unknown | |
114 | * file case. | |
115 | */ | |
116 | ||
117 | cache_name = active_cache[*indpos]->name; | |
118 | if (strlen(cache_name) > baselen && | |
119 | !memcmp(cache_name, base, baselen)) { | |
120 | cache_name += baselen; | |
121 | first = cache_name; | |
122 | } else { | |
123 | cache_name = NULL; | |
124 | } | |
125 | } | |
126 | ||
127 | #if DBRT_DEBUG > 1 | |
128 | if (first) | |
129 | printf("index %s\n", first); | |
130 | #endif | |
131 | for (i = 0; i < len; i++) { | |
132 | if (!posns[i] || posns[i] == df_conflict_list) | |
133 | continue; | |
134 | #if DBRT_DEBUG > 1 | |
135 | printf("%d %s\n", i + 1, posns[i]->name); | |
136 | #endif | |
137 | if (!first || entcmp(first, firstdir, | |
138 | posns[i]->name, | |
139 | posns[i]->directory) > 0) { | |
140 | first = posns[i]->name; | |
141 | firstdir = posns[i]->directory; | |
142 | } | |
143 | } | |
144 | /* No name means we're done */ | |
145 | if (!first) | |
146 | return 0; | |
147 | ||
148 | pathlen = strlen(first); | |
149 | ce_size = cache_entry_size(baselen + pathlen); | |
150 | ||
151 | src = xcalloc(src_size, sizeof(struct cache_entry *)); | |
152 | ||
153 | subposns = xcalloc(len, sizeof(struct tree_list_entry *)); | |
154 | ||
155 | if (cache_name && !strcmp(cache_name, first)) { | |
156 | any_files = 1; | |
157 | src[0] = active_cache[*indpos]; | |
158 | remove_cache_entry_at(*indpos); | |
159 | } | |
160 | ||
161 | for (i = 0; i < len; i++) { | |
162 | struct cache_entry *ce; | |
163 | ||
164 | if (!posns[i] || | |
165 | (posns[i] != df_conflict_list && | |
166 | strcmp(first, posns[i]->name))) { | |
167 | continue; | |
168 | } | |
169 | ||
170 | if (posns[i] == df_conflict_list) { | |
171 | src[i + o->merge] = o->df_conflict_entry; | |
172 | continue; | |
173 | } | |
174 | ||
175 | if (posns[i]->directory) { | |
176 | struct tree *tree = lookup_tree(posns[i]->sha1); | |
177 | any_dirs = 1; | |
178 | parse_tree(tree); | |
179 | subposns[i] = create_tree_entry_list(tree); | |
180 | posns[i] = posns[i]->next; | |
181 | src[i + o->merge] = o->df_conflict_entry; | |
182 | continue; | |
183 | } | |
184 | ||
185 | if (!o->merge) | |
186 | ce_stage = 0; | |
187 | else if (i + 1 < o->head_idx) | |
188 | ce_stage = 1; | |
189 | else if (i + 1 > o->head_idx) | |
190 | ce_stage = 3; | |
191 | else | |
192 | ce_stage = 2; | |
193 | ||
194 | ce = xcalloc(1, ce_size); | |
195 | ce->ce_mode = create_ce_mode(posns[i]->mode); | |
196 | ce->ce_flags = create_ce_flags(baselen + pathlen, | |
197 | ce_stage); | |
198 | memcpy(ce->name, base, baselen); | |
199 | memcpy(ce->name + baselen, first, pathlen + 1); | |
200 | ||
201 | any_files = 1; | |
202 | ||
e702496e | 203 | hashcpy(ce->sha1, posns[i]->sha1); |
16da134b JS |
204 | src[i + o->merge] = ce; |
205 | subposns[i] = df_conflict_list; | |
206 | posns[i] = posns[i]->next; | |
207 | } | |
208 | if (any_files) { | |
209 | if (o->merge) { | |
210 | int ret; | |
211 | ||
212 | #if DBRT_DEBUG > 1 | |
213 | printf("%s:\n", first); | |
214 | for (i = 0; i < src_size; i++) { | |
215 | printf(" %d ", i); | |
216 | if (src[i]) | |
217 | printf("%s\n", sha1_to_hex(src[i]->sha1)); | |
218 | else | |
219 | printf("\n"); | |
220 | } | |
221 | #endif | |
222 | ret = o->fn(src, o); | |
223 | ||
224 | #if DBRT_DEBUG > 1 | |
225 | printf("Added %d entries\n", ret); | |
226 | #endif | |
227 | *indpos += ret; | |
228 | } else { | |
229 | for (i = 0; i < src_size; i++) { | |
230 | if (src[i]) { | |
231 | add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK); | |
232 | } | |
233 | } | |
234 | } | |
235 | } | |
236 | if (any_dirs) { | |
237 | char *newbase = xmalloc(baselen + 2 + pathlen); | |
238 | memcpy(newbase, base, baselen); | |
239 | memcpy(newbase + baselen, first, pathlen); | |
240 | newbase[baselen + pathlen] = '/'; | |
241 | newbase[baselen + pathlen + 1] = '\0'; | |
242 | if (unpack_trees_rec(subposns, len, newbase, o, | |
243 | indpos, df_conflict_list)) | |
244 | return -1; | |
245 | free(newbase); | |
246 | } | |
247 | free(subposns); | |
248 | free(src); | |
249 | } while (1); | |
250 | } | |
251 | ||
252 | /* Unlink the last component and attempt to remove leading | |
253 | * directories, in case this unlink is the removal of the | |
254 | * last entry in the directory -- empty directories are removed. | |
255 | */ | |
256 | static void unlink_entry(char *name) | |
257 | { | |
258 | char *cp, *prev; | |
259 | ||
260 | if (unlink(name)) | |
261 | return; | |
262 | prev = NULL; | |
263 | while (1) { | |
264 | int status; | |
265 | cp = strrchr(name, '/'); | |
266 | if (prev) | |
267 | *prev = '/'; | |
268 | if (!cp) | |
269 | break; | |
270 | ||
271 | *cp = 0; | |
272 | status = rmdir(name); | |
273 | if (status) { | |
274 | *cp = '/'; | |
275 | break; | |
276 | } | |
277 | prev = cp; | |
278 | } | |
279 | } | |
280 | ||
96f1e58f | 281 | static volatile sig_atomic_t progress_update; |
16da134b JS |
282 | |
283 | static void progress_interval(int signum) | |
284 | { | |
285 | progress_update = 1; | |
286 | } | |
287 | ||
288 | static void setup_progress_signal(void) | |
289 | { | |
290 | struct sigaction sa; | |
291 | struct itimerval v; | |
292 | ||
293 | memset(&sa, 0, sizeof(sa)); | |
294 | sa.sa_handler = progress_interval; | |
295 | sigemptyset(&sa.sa_mask); | |
296 | sa.sa_flags = SA_RESTART; | |
297 | sigaction(SIGALRM, &sa, NULL); | |
298 | ||
299 | v.it_interval.tv_sec = 1; | |
300 | v.it_interval.tv_usec = 0; | |
301 | v.it_value = v.it_interval; | |
302 | setitimer(ITIMER_REAL, &v, NULL); | |
303 | } | |
304 | ||
305 | static struct checkout state; | |
306 | static void check_updates(struct cache_entry **src, int nr, | |
307 | struct unpack_trees_options *o) | |
308 | { | |
309 | unsigned short mask = htons(CE_UPDATE); | |
310 | unsigned last_percent = 200, cnt = 0, total = 0; | |
311 | ||
312 | if (o->update && o->verbose_update) { | |
313 | for (total = cnt = 0; cnt < nr; cnt++) { | |
314 | struct cache_entry *ce = src[cnt]; | |
315 | if (!ce->ce_mode || ce->ce_flags & mask) | |
316 | total++; | |
317 | } | |
318 | ||
319 | /* Don't bother doing this for very small updates */ | |
320 | if (total < 250) | |
321 | total = 0; | |
322 | ||
323 | if (total) { | |
324 | fprintf(stderr, "Checking files out...\n"); | |
325 | setup_progress_signal(); | |
326 | progress_update = 1; | |
327 | } | |
328 | cnt = 0; | |
329 | } | |
330 | ||
331 | while (nr--) { | |
332 | struct cache_entry *ce = *src++; | |
333 | ||
334 | if (total) { | |
335 | if (!ce->ce_mode || ce->ce_flags & mask) { | |
336 | unsigned percent; | |
337 | cnt++; | |
338 | percent = (cnt * 100) / total; | |
339 | if (percent != last_percent || | |
340 | progress_update) { | |
341 | fprintf(stderr, "%4u%% (%u/%u) done\r", | |
342 | percent, cnt, total); | |
343 | last_percent = percent; | |
344 | progress_update = 0; | |
345 | } | |
346 | } | |
347 | } | |
348 | if (!ce->ce_mode) { | |
349 | if (o->update) | |
350 | unlink_entry(ce->name); | |
351 | continue; | |
352 | } | |
353 | if (ce->ce_flags & mask) { | |
354 | ce->ce_flags &= ~mask; | |
355 | if (o->update) | |
356 | checkout_entry(ce, &state, NULL); | |
357 | } | |
358 | } | |
359 | if (total) { | |
360 | signal(SIGALRM, SIG_IGN); | |
361 | fputc('\n', stderr); | |
362 | } | |
363 | } | |
364 | ||
365 | int unpack_trees(struct object_list *trees, struct unpack_trees_options *o) | |
366 | { | |
367 | int indpos = 0; | |
368 | unsigned len = object_list_length(trees); | |
369 | struct tree_entry_list **posns; | |
370 | int i; | |
371 | struct object_list *posn = trees; | |
372 | struct tree_entry_list df_conflict_list; | |
373 | struct cache_entry df_conflict_entry; | |
374 | ||
375 | memset(&df_conflict_list, 0, sizeof(df_conflict_list)); | |
376 | df_conflict_list.next = &df_conflict_list; | |
076b0adc | 377 | memset(&state, 0, sizeof(state)); |
16da134b JS |
378 | state.base_dir = ""; |
379 | state.force = 1; | |
380 | state.quiet = 1; | |
381 | state.refresh_cache = 1; | |
382 | ||
383 | o->merge_size = len; | |
076b0adc | 384 | memset(&df_conflict_entry, 0, sizeof(df_conflict_entry)); |
16da134b JS |
385 | o->df_conflict_entry = &df_conflict_entry; |
386 | ||
387 | if (len) { | |
388 | posns = xmalloc(len * sizeof(struct tree_entry_list *)); | |
389 | for (i = 0; i < len; i++) { | |
390 | posns[i] = create_tree_entry_list((struct tree *) posn->item); | |
391 | posn = posn->next; | |
392 | } | |
393 | if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "", | |
394 | o, &indpos, &df_conflict_list)) | |
395 | return -1; | |
396 | } | |
397 | ||
398 | if (o->trivial_merges_only && o->nontrivial_merge) | |
399 | die("Merge requires file-level merging"); | |
400 | ||
401 | check_updates(active_cache, active_nr, o); | |
402 | return 0; | |
403 | } | |
076b0adc JS |
404 | |
405 | /* Here come the merge functions */ | |
406 | ||
407 | static void reject_merge(struct cache_entry *ce) | |
408 | { | |
409 | die("Entry '%s' would be overwritten by merge. Cannot merge.", | |
410 | ce->name); | |
411 | } | |
412 | ||
413 | static int same(struct cache_entry *a, struct cache_entry *b) | |
414 | { | |
415 | if (!!a != !!b) | |
416 | return 0; | |
417 | if (!a && !b) | |
418 | return 1; | |
419 | return a->ce_mode == b->ce_mode && | |
a89fccd2 | 420 | !hashcmp(a->sha1, b->sha1); |
076b0adc JS |
421 | } |
422 | ||
423 | ||
424 | /* | |
425 | * When a CE gets turned into an unmerged entry, we | |
426 | * want it to be up-to-date | |
427 | */ | |
428 | static void verify_uptodate(struct cache_entry *ce, | |
429 | struct unpack_trees_options *o) | |
430 | { | |
431 | struct stat st; | |
432 | ||
433 | if (o->index_only || o->reset) | |
434 | return; | |
435 | ||
436 | if (!lstat(ce->name, &st)) { | |
437 | unsigned changed = ce_match_stat(ce, &st, 1); | |
438 | if (!changed) | |
439 | return; | |
440 | errno = 0; | |
441 | } | |
442 | if (o->reset) { | |
443 | ce->ce_flags |= htons(CE_UPDATE); | |
444 | return; | |
445 | } | |
446 | if (errno == ENOENT) | |
447 | return; | |
448 | die("Entry '%s' not uptodate. Cannot merge.", ce->name); | |
449 | } | |
450 | ||
451 | static void invalidate_ce_path(struct cache_entry *ce) | |
452 | { | |
453 | if (ce) | |
454 | cache_tree_invalidate_path(active_cache_tree, ce->name); | |
455 | } | |
456 | ||
457 | /* | |
458 | * We do not want to remove or overwrite a working tree file that | |
459 | * is not tracked. | |
460 | */ | |
461 | static void verify_absent(const char *path, const char *action, | |
462 | struct unpack_trees_options *o) | |
463 | { | |
464 | struct stat st; | |
465 | ||
466 | if (o->index_only || o->reset || !o->update) | |
467 | return; | |
468 | if (!lstat(path, &st)) | |
469 | die("Untracked working tree file '%s' " | |
470 | "would be %s by merge.", path, action); | |
471 | } | |
472 | ||
473 | static int merged_entry(struct cache_entry *merge, struct cache_entry *old, | |
474 | struct unpack_trees_options *o) | |
475 | { | |
476 | merge->ce_flags |= htons(CE_UPDATE); | |
477 | if (old) { | |
478 | /* | |
479 | * See if we can re-use the old CE directly? | |
480 | * That way we get the uptodate stat info. | |
481 | * | |
482 | * This also removes the UPDATE flag on | |
483 | * a match. | |
484 | */ | |
485 | if (same(old, merge)) { | |
486 | *merge = *old; | |
487 | } else { | |
488 | verify_uptodate(old, o); | |
489 | invalidate_ce_path(old); | |
490 | } | |
491 | } | |
492 | else { | |
493 | verify_absent(merge->name, "overwritten", o); | |
494 | invalidate_ce_path(merge); | |
495 | } | |
496 | ||
497 | merge->ce_flags &= ~htons(CE_STAGEMASK); | |
498 | add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); | |
499 | return 1; | |
500 | } | |
501 | ||
502 | static int deleted_entry(struct cache_entry *ce, struct cache_entry *old, | |
503 | struct unpack_trees_options *o) | |
504 | { | |
505 | if (old) | |
506 | verify_uptodate(old, o); | |
507 | else | |
508 | verify_absent(ce->name, "removed", o); | |
509 | ce->ce_mode = 0; | |
510 | add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); | |
511 | invalidate_ce_path(ce); | |
512 | return 1; | |
513 | } | |
514 | ||
515 | static int keep_entry(struct cache_entry *ce) | |
516 | { | |
517 | add_cache_entry(ce, ADD_CACHE_OK_TO_ADD); | |
518 | return 1; | |
519 | } | |
520 | ||
521 | #if DBRT_DEBUG | |
522 | static void show_stage_entry(FILE *o, | |
523 | const char *label, const struct cache_entry *ce) | |
524 | { | |
525 | if (!ce) | |
526 | fprintf(o, "%s (missing)\n", label); | |
527 | else | |
528 | fprintf(o, "%s%06o %s %d\t%s\n", | |
529 | label, | |
530 | ntohl(ce->ce_mode), | |
531 | sha1_to_hex(ce->sha1), | |
532 | ce_stage(ce), | |
533 | ce->name); | |
534 | } | |
535 | #endif | |
536 | ||
537 | int threeway_merge(struct cache_entry **stages, | |
538 | struct unpack_trees_options *o) | |
539 | { | |
540 | struct cache_entry *index; | |
541 | struct cache_entry *head; | |
542 | struct cache_entry *remote = stages[o->head_idx + 1]; | |
543 | int count; | |
544 | int head_match = 0; | |
545 | int remote_match = 0; | |
546 | const char *path = NULL; | |
547 | ||
548 | int df_conflict_head = 0; | |
549 | int df_conflict_remote = 0; | |
550 | ||
551 | int any_anc_missing = 0; | |
552 | int no_anc_exists = 1; | |
553 | int i; | |
554 | ||
555 | for (i = 1; i < o->head_idx; i++) { | |
556 | if (!stages[i]) | |
557 | any_anc_missing = 1; | |
558 | else { | |
559 | if (!path) | |
560 | path = stages[i]->name; | |
561 | no_anc_exists = 0; | |
562 | } | |
563 | } | |
564 | ||
565 | index = stages[0]; | |
566 | head = stages[o->head_idx]; | |
567 | ||
568 | if (head == o->df_conflict_entry) { | |
569 | df_conflict_head = 1; | |
570 | head = NULL; | |
571 | } | |
572 | ||
573 | if (remote == o->df_conflict_entry) { | |
574 | df_conflict_remote = 1; | |
575 | remote = NULL; | |
576 | } | |
577 | ||
578 | if (!path && index) | |
579 | path = index->name; | |
580 | if (!path && head) | |
581 | path = head->name; | |
582 | if (!path && remote) | |
583 | path = remote->name; | |
584 | ||
585 | /* First, if there's a #16 situation, note that to prevent #13 | |
586 | * and #14. | |
587 | */ | |
588 | if (!same(remote, head)) { | |
589 | for (i = 1; i < o->head_idx; i++) { | |
590 | if (same(stages[i], head)) { | |
591 | head_match = i; | |
592 | } | |
593 | if (same(stages[i], remote)) { | |
594 | remote_match = i; | |
595 | } | |
596 | } | |
597 | } | |
598 | ||
599 | /* We start with cases where the index is allowed to match | |
600 | * something other than the head: #14(ALT) and #2ALT, where it | |
601 | * is permitted to match the result instead. | |
602 | */ | |
603 | /* #14, #14ALT, #2ALT */ | |
604 | if (remote && !df_conflict_head && head_match && !remote_match) { | |
605 | if (index && !same(index, remote) && !same(index, head)) | |
606 | reject_merge(index); | |
607 | return merged_entry(remote, index, o); | |
608 | } | |
609 | /* | |
610 | * If we have an entry in the index cache, then we want to | |
611 | * make sure that it matches head. | |
612 | */ | |
613 | if (index && !same(index, head)) { | |
614 | reject_merge(index); | |
615 | } | |
616 | ||
617 | if (head) { | |
618 | /* #5ALT, #15 */ | |
619 | if (same(head, remote)) | |
620 | return merged_entry(head, index, o); | |
621 | /* #13, #3ALT */ | |
622 | if (!df_conflict_remote && remote_match && !head_match) | |
623 | return merged_entry(head, index, o); | |
624 | } | |
625 | ||
626 | /* #1 */ | |
627 | if (!head && !remote && any_anc_missing) | |
628 | return 0; | |
629 | ||
630 | /* Under the new "aggressive" rule, we resolve mostly trivial | |
631 | * cases that we historically had git-merge-one-file resolve. | |
632 | */ | |
633 | if (o->aggressive) { | |
634 | int head_deleted = !head && !df_conflict_head; | |
635 | int remote_deleted = !remote && !df_conflict_remote; | |
636 | /* | |
637 | * Deleted in both. | |
638 | * Deleted in one and unchanged in the other. | |
639 | */ | |
640 | if ((head_deleted && remote_deleted) || | |
641 | (head_deleted && remote && remote_match) || | |
642 | (remote_deleted && head && head_match)) { | |
643 | if (index) | |
644 | return deleted_entry(index, index, o); | |
645 | else if (path) | |
646 | verify_absent(path, "removed", o); | |
647 | return 0; | |
648 | } | |
649 | /* | |
650 | * Added in both, identically. | |
651 | */ | |
652 | if (no_anc_exists && head && remote && same(head, remote)) | |
653 | return merged_entry(head, index, o); | |
654 | ||
655 | } | |
656 | ||
657 | /* Below are "no merge" cases, which require that the index be | |
658 | * up-to-date to avoid the files getting overwritten with | |
659 | * conflict resolution files. | |
660 | */ | |
661 | if (index) { | |
662 | verify_uptodate(index, o); | |
663 | } | |
664 | else if (path) | |
665 | verify_absent(path, "overwritten", o); | |
666 | ||
667 | o->nontrivial_merge = 1; | |
668 | ||
669 | /* #2, #3, #4, #6, #7, #9, #11. */ | |
670 | count = 0; | |
671 | if (!head_match || !remote_match) { | |
672 | for (i = 1; i < o->head_idx; i++) { | |
673 | if (stages[i]) { | |
674 | keep_entry(stages[i]); | |
675 | count++; | |
676 | break; | |
677 | } | |
678 | } | |
679 | } | |
680 | #if DBRT_DEBUG | |
681 | else { | |
682 | fprintf(stderr, "read-tree: warning #16 detected\n"); | |
683 | show_stage_entry(stderr, "head ", stages[head_match]); | |
684 | show_stage_entry(stderr, "remote ", stages[remote_match]); | |
685 | } | |
686 | #endif | |
687 | if (head) { count += keep_entry(head); } | |
688 | if (remote) { count += keep_entry(remote); } | |
689 | return count; | |
690 | } | |
691 | ||
692 | /* | |
693 | * Two-way merge. | |
694 | * | |
695 | * The rule is to "carry forward" what is in the index without losing | |
696 | * information across a "fast forward", favoring a successful merge | |
697 | * over a merge failure when it makes sense. For details of the | |
698 | * "carry forward" rule, please see <Documentation/git-read-tree.txt>. | |
699 | * | |
700 | */ | |
701 | int twoway_merge(struct cache_entry **src, | |
702 | struct unpack_trees_options *o) | |
703 | { | |
704 | struct cache_entry *current = src[0]; | |
705 | struct cache_entry *oldtree = src[1], *newtree = src[2]; | |
706 | ||
707 | if (o->merge_size != 2) | |
708 | return error("Cannot do a twoway merge of %d trees", | |
709 | o->merge_size); | |
710 | ||
711 | if (current) { | |
712 | if ((!oldtree && !newtree) || /* 4 and 5 */ | |
713 | (!oldtree && newtree && | |
714 | same(current, newtree)) || /* 6 and 7 */ | |
715 | (oldtree && newtree && | |
716 | same(oldtree, newtree)) || /* 14 and 15 */ | |
717 | (oldtree && newtree && | |
718 | !same(oldtree, newtree) && /* 18 and 19*/ | |
719 | same(current, newtree))) { | |
720 | return keep_entry(current); | |
721 | } | |
722 | else if (oldtree && !newtree && same(current, oldtree)) { | |
723 | /* 10 or 11 */ | |
724 | return deleted_entry(oldtree, current, o); | |
725 | } | |
726 | else if (oldtree && newtree && | |
727 | same(current, oldtree) && !same(current, newtree)) { | |
728 | /* 20 or 21 */ | |
729 | return merged_entry(newtree, current, o); | |
730 | } | |
731 | else { | |
732 | /* all other failures */ | |
733 | if (oldtree) | |
734 | reject_merge(oldtree); | |
735 | if (current) | |
736 | reject_merge(current); | |
737 | if (newtree) | |
738 | reject_merge(newtree); | |
739 | return -1; | |
740 | } | |
741 | } | |
742 | else if (newtree) | |
743 | return merged_entry(newtree, current, o); | |
744 | else | |
745 | return deleted_entry(oldtree, current, o); | |
746 | } | |
747 | ||
748 | /* | |
749 | * Bind merge. | |
750 | * | |
751 | * Keep the index entries at stage0, collapse stage1 but make sure | |
752 | * stage0 does not have anything there. | |
753 | */ | |
754 | int bind_merge(struct cache_entry **src, | |
755 | struct unpack_trees_options *o) | |
756 | { | |
757 | struct cache_entry *old = src[0]; | |
758 | struct cache_entry *a = src[1]; | |
759 | ||
760 | if (o->merge_size != 1) | |
761 | return error("Cannot do a bind merge of %d trees\n", | |
762 | o->merge_size); | |
763 | if (a && old) | |
764 | die("Entry '%s' overlaps. Cannot bind.", a->name); | |
765 | if (!a) | |
766 | return keep_entry(old); | |
767 | else | |
768 | return merged_entry(a, NULL, o); | |
769 | } | |
770 | ||
771 | /* | |
772 | * One-way merge. | |
773 | * | |
774 | * The rule is: | |
775 | * - take the stat information from stage0, take the data from stage1 | |
776 | */ | |
777 | int oneway_merge(struct cache_entry **src, | |
778 | struct unpack_trees_options *o) | |
779 | { | |
780 | struct cache_entry *old = src[0]; | |
781 | struct cache_entry *a = src[1]; | |
782 | ||
783 | if (o->merge_size != 1) | |
784 | return error("Cannot do a oneway merge of %d trees", | |
785 | o->merge_size); | |
786 | ||
787 | if (!a) | |
788 | return deleted_entry(old, old, o); | |
789 | if (old && same(old, a)) { | |
790 | if (o->reset) { | |
791 | struct stat st; | |
792 | if (lstat(old->name, &st) || | |
793 | ce_match_stat(old, &st, 1)) | |
794 | old->ce_flags |= htons(CE_UPDATE); | |
795 | } | |
796 | return keep_entry(old); | |
797 | } | |
798 | return merged_entry(a, old, o); | |
799 | } |