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double free in builtin-update-index.c
[git/jrn.git] / merge-recursive.c
blob86767e6e8a37ce7874aa80b789cfef780fa9b136
1 /*
2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
3 * Fredrik Kuivinen.
4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5 */
6 #include "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "tree-walk.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "run-command.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "interpolate.h"
19 #include "attr.h"
20
21 static int subtree_merge;
22
23 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
24 {
25 unsigned char shifted[20];
26
27 /*
28 * NEEDSWORK: this limits the recursion depth to hardcoded
29 * value '2' to avoid excessive overhead.
30 */
31 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
32 if (!hashcmp(two->object.sha1, shifted))
33 return two;
34 return lookup_tree(shifted);
35 }
36
37 /*
38 * A virtual commit has
39 * - (const char *)commit->util set to the name, and
40 * - *(int *)commit->object.sha1 set to the virtual id.
41 */
42
43 static unsigned commit_list_count(const struct commit_list *l)
44 {
45 unsigned c = 0;
46 for (; l; l = l->next )
47 c++;
48 return c;
49 }
50
51 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
52 {
53 struct commit *commit = xcalloc(1, sizeof(struct commit));
54 static unsigned virtual_id = 1;
55 commit->tree = tree;
56 commit->util = (void*)comment;
57 *(int*)commit->object.sha1 = virtual_id++;
58 /* avoid warnings */
59 commit->object.parsed = 1;
60 return commit;
61 }
62
63 /*
64 * Since we use get_tree_entry(), which does not put the read object into
65 * the object pool, we cannot rely on a == b.
66 */
67 static int sha_eq(const unsigned char *a, const unsigned char *b)
68 {
69 if (!a && !b)
70 return 2;
71 return a && b && hashcmp(a, b) == 0;
72 }
73
74 /*
75 * Since we want to write the index eventually, we cannot reuse the index
76 * for these (temporary) data.
77 */
78 struct stage_data
79 {
80 struct
81 {
82 unsigned mode;
83 unsigned char sha[20];
84 } stages[4];
85 unsigned processed:1;
86 };
87
88 static struct path_list current_file_set = {NULL, 0, 0, 1};
89 static struct path_list current_directory_set = {NULL, 0, 0, 1};
90
91 static int call_depth = 0;
92 static int verbosity = 2;
93 static int buffer_output = 1;
94 static struct strbuf obuf = STRBUF_INIT;
95
96 static int show(int v)
97 {
98 return (!call_depth && verbosity >= v) || verbosity >= 5;
99 }
100
101 static void flush_output(void)
102 {
103 if (obuf.len) {
104 fputs(obuf.buf, stdout);
105 strbuf_reset(&obuf);
106 }
107 }
108
109 static void output(int v, const char *fmt, ...)
110 {
111 int len;
112 va_list ap;
113
114 if (!show(v))
115 return;
116
117 strbuf_grow(&obuf, call_depth * 2 + 2);
118 memset(obuf.buf + obuf.len, ' ', call_depth * 2);
119 strbuf_setlen(&obuf, obuf.len + call_depth * 2);
120
121 va_start(ap, fmt);
122 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
123 va_end(ap);
124
125 if (len < 0)
126 len = 0;
127 if (len >= strbuf_avail(&obuf)) {
128 strbuf_grow(&obuf, len + 2);
129 va_start(ap, fmt);
130 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
131 va_end(ap);
132 if (len >= strbuf_avail(&obuf)) {
133 die("this should not happen, your snprintf is broken");
134 }
135 }
136 strbuf_setlen(&obuf, obuf.len + len);
137 strbuf_add(&obuf, "\n", 1);
138 if (!buffer_output)
139 flush_output();
140 }
141
142 static void output_commit_title(struct commit *commit)
143 {
144 int i;
145 flush_output();
146 for (i = call_depth; i--;)
147 fputs(" ", stdout);
148 if (commit->util)
149 printf("virtual %s\n", (char *)commit->util);
150 else {
151 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
152 if (parse_commit(commit) != 0)
153 printf("(bad commit)\n");
154 else {
155 const char *s;
156 int len;
157 for (s = commit->buffer; *s; s++)
158 if (*s == '\n' && s[1] == '\n') {
159 s += 2;
160 break;
161 }
162 for (len = 0; s[len] && '\n' != s[len]; len++)
163 ; /* do nothing */
164 printf("%.*s\n", len, s);
165 }
166 }
167 }
168
169 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
170 const char *path, int stage, int refresh, int options)
171 {
172 struct cache_entry *ce;
173 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
174 if (!ce)
175 return error("addinfo_cache failed for path '%s'", path);
176 return add_cache_entry(ce, options);
177 }
178
179 /*
180 * This is a global variable which is used in a number of places but
181 * only written to in the 'merge' function.
182 *
183 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
184 * don't update the working directory.
185 * 0 => Leave unmerged entries in the cache and update
186 * the working directory.
187 */
188 static int index_only = 0;
189
190 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
191 {
192 parse_tree(tree);
193 init_tree_desc(desc, tree->buffer, tree->size);
194 }
195
196 static int git_merge_trees(int index_only,
197 struct tree *common,
198 struct tree *head,
199 struct tree *merge)
200 {
201 int rc;
202 struct tree_desc t[3];
203 struct unpack_trees_options opts;
204
205 memset(&opts, 0, sizeof(opts));
206 if (index_only)
207 opts.index_only = 1;
208 else
209 opts.update = 1;
210 opts.merge = 1;
211 opts.head_idx = 2;
212 opts.fn = threeway_merge;
213
214 init_tree_desc_from_tree(t+0, common);
215 init_tree_desc_from_tree(t+1, head);
216 init_tree_desc_from_tree(t+2, merge);
217
218 rc = unpack_trees(3, t, &opts);
219 cache_tree_free(&active_cache_tree);
220 return rc;
221 }
222
223 static int unmerged_index(void)
224 {
225 int i;
226 for (i = 0; i < active_nr; i++) {
227 struct cache_entry *ce = active_cache[i];
228 if (ce_stage(ce))
229 return 1;
230 }
231 return 0;
232 }
233
234 static struct tree *git_write_tree(void)
235 {
236 struct tree *result = NULL;
237
238 if (unmerged_index()) {
239 int i;
240 output(0, "There are unmerged index entries:");
241 for (i = 0; i < active_nr; i++) {
242 struct cache_entry *ce = active_cache[i];
243 if (ce_stage(ce))
244 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
245 }
246 return NULL;
247 }
248
249 if (!active_cache_tree)
250 active_cache_tree = cache_tree();
251
252 if (!cache_tree_fully_valid(active_cache_tree) &&
253 cache_tree_update(active_cache_tree,
254 active_cache, active_nr, 0, 0) < 0)
255 die("error building trees");
256
257 result = lookup_tree(active_cache_tree->sha1);
258
259 return result;
260 }
261
262 static int save_files_dirs(const unsigned char *sha1,
263 const char *base, int baselen, const char *path,
264 unsigned int mode, int stage)
265 {
266 int len = strlen(path);
267 char *newpath = xmalloc(baselen + len + 1);
268 memcpy(newpath, base, baselen);
269 memcpy(newpath + baselen, path, len);
270 newpath[baselen + len] = '\0';
271
272 if (S_ISDIR(mode))
273 path_list_insert(newpath, &current_directory_set);
274 else
275 path_list_insert(newpath, &current_file_set);
276 free(newpath);
277
278 return READ_TREE_RECURSIVE;
279 }
280
281 static int get_files_dirs(struct tree *tree)
282 {
283 int n;
284 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
285 return 0;
286 n = current_file_set.nr + current_directory_set.nr;
287 return n;
288 }
289
290 /*
291 * Returns a index_entry instance which doesn't have to correspond to
292 * a real cache entry in Git's index.
293 */
294 static struct stage_data *insert_stage_data(const char *path,
295 struct tree *o, struct tree *a, struct tree *b,
296 struct path_list *entries)
297 {
298 struct path_list_item *item;
299 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
300 get_tree_entry(o->object.sha1, path,
301 e->stages[1].sha, &e->stages[1].mode);
302 get_tree_entry(a->object.sha1, path,
303 e->stages[2].sha, &e->stages[2].mode);
304 get_tree_entry(b->object.sha1, path,
305 e->stages[3].sha, &e->stages[3].mode);
306 item = path_list_insert(path, entries);
307 item->util = e;
308 return e;
309 }
310
311 /*
312 * Create a dictionary mapping file names to stage_data objects. The
313 * dictionary contains one entry for every path with a non-zero stage entry.
314 */
315 static struct path_list *get_unmerged(void)
316 {
317 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
318 int i;
319
320 unmerged->strdup_paths = 1;
321
322 for (i = 0; i < active_nr; i++) {
323 struct path_list_item *item;
324 struct stage_data *e;
325 struct cache_entry *ce = active_cache[i];
326 if (!ce_stage(ce))
327 continue;
328
329 item = path_list_lookup(ce->name, unmerged);
330 if (!item) {
331 item = path_list_insert(ce->name, unmerged);
332 item->util = xcalloc(1, sizeof(struct stage_data));
333 }
334 e = item->util;
335 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
336 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
337 }
338
339 return unmerged;
340 }
341
342 struct rename
343 {
344 struct diff_filepair *pair;
345 struct stage_data *src_entry;
346 struct stage_data *dst_entry;
347 unsigned processed:1;
348 };
349
350 /*
351 * Get information of all renames which occurred between 'o_tree' and
352 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
353 * 'b_tree') to be able to associate the correct cache entries with
354 * the rename information. 'tree' is always equal to either a_tree or b_tree.
355 */
356 static struct path_list *get_renames(struct tree *tree,
357 struct tree *o_tree,
358 struct tree *a_tree,
359 struct tree *b_tree,
360 struct path_list *entries)
361 {
362 int i;
363 struct path_list *renames;
364 struct diff_options opts;
365
366 renames = xcalloc(1, sizeof(struct path_list));
367 diff_setup(&opts);
368 opts.recursive = 1;
369 opts.detect_rename = DIFF_DETECT_RENAME;
370 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
371 if (diff_setup_done(&opts) < 0)
372 die("diff setup failed");
373 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
374 diffcore_std(&opts);
375 for (i = 0; i < diff_queued_diff.nr; ++i) {
376 struct path_list_item *item;
377 struct rename *re;
378 struct diff_filepair *pair = diff_queued_diff.queue[i];
379 if (pair->status != 'R') {
380 diff_free_filepair(pair);
381 continue;
382 }
383 re = xmalloc(sizeof(*re));
384 re->processed = 0;
385 re->pair = pair;
386 item = path_list_lookup(re->pair->one->path, entries);
387 if (!item)
388 re->src_entry = insert_stage_data(re->pair->one->path,
389 o_tree, a_tree, b_tree, entries);
390 else
391 re->src_entry = item->util;
392
393 item = path_list_lookup(re->pair->two->path, entries);
394 if (!item)
395 re->dst_entry = insert_stage_data(re->pair->two->path,
396 o_tree, a_tree, b_tree, entries);
397 else
398 re->dst_entry = item->util;
399 item = path_list_insert(pair->one->path, renames);
400 item->util = re;
401 }
402 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
403 diff_queued_diff.nr = 0;
404 diff_flush(&opts);
405 return renames;
406 }
407
408 static int update_stages(const char *path, struct diff_filespec *o,
409 struct diff_filespec *a, struct diff_filespec *b,
410 int clear)
411 {
412 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
413 if (clear)
414 if (remove_file_from_cache(path))
415 return -1;
416 if (o)
417 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
418 return -1;
419 if (a)
420 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
421 return -1;
422 if (b)
423 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
424 return -1;
425 return 0;
426 }
427
428 static int remove_path(const char *name)
429 {
430 int ret;
431 char *slash, *dirs;
432
433 ret = unlink(name);
434 if (ret)
435 return ret;
436 dirs = xstrdup(name);
437 while ((slash = strrchr(name, '/'))) {
438 *slash = '\0';
439 if (rmdir(name) != 0)
440 break;
441 }
442 free(dirs);
443 return ret;
444 }
445
446 static int remove_file(int clean, const char *path, int no_wd)
447 {
448 int update_cache = index_only || clean;
449 int update_working_directory = !index_only && !no_wd;
450
451 if (update_cache) {
452 if (remove_file_from_cache(path))
453 return -1;
454 }
455 if (update_working_directory) {
456 unlink(path);
457 if (errno != ENOENT || errno != EISDIR)
458 return -1;
459 remove_path(path);
460 }
461 return 0;
462 }
463
464 static char *unique_path(const char *path, const char *branch)
465 {
466 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
467 int suffix = 0;
468 struct stat st;
469 char *p = newpath + strlen(path);
470 strcpy(newpath, path);
471 *(p++) = '~';
472 strcpy(p, branch);
473 for (; *p; ++p)
474 if ('/' == *p)
475 *p = '_';
476 while (path_list_has_path(&current_file_set, newpath) ||
477 path_list_has_path(&current_directory_set, newpath) ||
478 lstat(newpath, &st) == 0)
479 sprintf(p, "_%d", suffix++);
480
481 path_list_insert(newpath, &current_file_set);
482 return newpath;
483 }
484
485 static int mkdir_p(const char *path, unsigned long mode)
486 {
487 /* path points to cache entries, so xstrdup before messing with it */
488 char *buf = xstrdup(path);
489 int result = safe_create_leading_directories(buf);
490 free(buf);
491 return result;
492 }
493
494 static void flush_buffer(int fd, const char *buf, unsigned long size)
495 {
496 while (size > 0) {
497 long ret = write_in_full(fd, buf, size);
498 if (ret < 0) {
499 /* Ignore epipe */
500 if (errno == EPIPE)
501 break;
502 die("merge-recursive: %s", strerror(errno));
503 } else if (!ret) {
504 die("merge-recursive: disk full?");
505 }
506 size -= ret;
507 buf += ret;
508 }
509 }
510
511 static int make_room_for_path(const char *path)
512 {
513 int status;
514 const char *msg = "failed to create path '%s'%s";
515
516 status = mkdir_p(path, 0777);
517 if (status) {
518 if (status == -3) {
519 /* something else exists */
520 error(msg, path, ": perhaps a D/F conflict?");
521 return -1;
522 }
523 die(msg, path, "");
524 }
525
526 /* Successful unlink is good.. */
527 if (!unlink(path))
528 return 0;
529 /* .. and so is no existing file */
530 if (errno == ENOENT)
531 return 0;
532 /* .. but not some other error (who really cares what?) */
533 return error(msg, path, ": perhaps a D/F conflict?");
534 }
535
536 static void update_file_flags(const unsigned char *sha,
537 unsigned mode,
538 const char *path,
539 int update_cache,
540 int update_wd)
541 {
542 if (index_only)
543 update_wd = 0;
544
545 if (update_wd) {
546 enum object_type type;
547 void *buf;
548 unsigned long size;
549
550 buf = read_sha1_file(sha, &type, &size);
551 if (!buf)
552 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
553 if (type != OBJ_BLOB)
554 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
555
556 if (make_room_for_path(path) < 0) {
557 update_wd = 0;
558 goto update_index;
559 }
560 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
561 int fd;
562 if (mode & 0100)
563 mode = 0777;
564 else
565 mode = 0666;
566 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
567 if (fd < 0)
568 die("failed to open %s: %s", path, strerror(errno));
569 flush_buffer(fd, buf, size);
570 close(fd);
571 } else if (S_ISLNK(mode)) {
572 char *lnk = xmemdupz(buf, size);
573 mkdir_p(path, 0777);
574 unlink(path);
575 symlink(lnk, path);
576 free(lnk);
577 } else
578 die("do not know what to do with %06o %s '%s'",
579 mode, sha1_to_hex(sha), path);
580 }
581 update_index:
582 if (update_cache)
583 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
584 }
585
586 static void update_file(int clean,
587 const unsigned char *sha,
588 unsigned mode,
589 const char *path)
590 {
591 update_file_flags(sha, mode, path, index_only || clean, !index_only);
592 }
593
594 /* Low level file merging, update and removal */
595
596 struct merge_file_info
597 {
598 unsigned char sha[20];
599 unsigned mode;
600 unsigned clean:1,
601 merge:1;
602 };
603
604 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
605 {
606 unsigned long size;
607 enum object_type type;
608
609 if (!hashcmp(sha1, null_sha1)) {
610 mm->ptr = xstrdup("");
611 mm->size = 0;
612 return;
613 }
614
615 mm->ptr = read_sha1_file(sha1, &type, &size);
616 if (!mm->ptr || type != OBJ_BLOB)
617 die("unable to read blob object %s", sha1_to_hex(sha1));
618 mm->size = size;
619 }
620
621 /*
622 * Customizable low-level merge drivers support.
623 */
624
625 struct ll_merge_driver;
626 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
627 const char *path,
628 mmfile_t *orig,
629 mmfile_t *src1, const char *name1,
630 mmfile_t *src2, const char *name2,
631 mmbuffer_t *result);
632
633 struct ll_merge_driver {
634 const char *name;
635 const char *description;
636 ll_merge_fn fn;
637 const char *recursive;
638 struct ll_merge_driver *next;
639 char *cmdline;
640 };
641
642 /*
643 * Built-in low-levels
644 */
645 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
646 const char *path_unused,
647 mmfile_t *orig,
648 mmfile_t *src1, const char *name1,
649 mmfile_t *src2, const char *name2,
650 mmbuffer_t *result)
651 {
652 /*
653 * The tentative merge result is "ours" for the final round,
654 * or common ancestor for an internal merge. Still return
655 * "conflicted merge" status.
656 */
657 mmfile_t *stolen = index_only ? orig : src1;
658
659 result->ptr = stolen->ptr;
660 result->size = stolen->size;
661 stolen->ptr = NULL;
662 return 1;
663 }
664
665 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
666 const char *path_unused,
667 mmfile_t *orig,
668 mmfile_t *src1, const char *name1,
669 mmfile_t *src2, const char *name2,
670 mmbuffer_t *result)
671 {
672 xpparam_t xpp;
673
674 if (buffer_is_binary(orig->ptr, orig->size) ||
675 buffer_is_binary(src1->ptr, src1->size) ||
676 buffer_is_binary(src2->ptr, src2->size)) {
677 warning("Cannot merge binary files: %s vs. %s\n",
678 name1, name2);
679 return ll_binary_merge(drv_unused, path_unused,
680 orig, src1, name1,
681 src2, name2,
682 result);
683 }
684
685 memset(&xpp, 0, sizeof(xpp));
686 return xdl_merge(orig,
687 src1, name1,
688 src2, name2,
689 &xpp, XDL_MERGE_ZEALOUS,
690 result);
691 }
692
693 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
694 const char *path_unused,
695 mmfile_t *orig,
696 mmfile_t *src1, const char *name1,
697 mmfile_t *src2, const char *name2,
698 mmbuffer_t *result)
699 {
700 char *src, *dst;
701 long size;
702 const int marker_size = 7;
703
704 int status = ll_xdl_merge(drv_unused, path_unused,
705 orig, src1, NULL, src2, NULL, result);
706 if (status <= 0)
707 return status;
708 size = result->size;
709 src = dst = result->ptr;
710 while (size) {
711 char ch;
712 if ((marker_size < size) &&
713 (*src == '<' || *src == '=' || *src == '>')) {
714 int i;
715 ch = *src;
716 for (i = 0; i < marker_size; i++)
717 if (src[i] != ch)
718 goto not_a_marker;
719 if (src[marker_size] != '\n')
720 goto not_a_marker;
721 src += marker_size + 1;
722 size -= marker_size + 1;
723 continue;
724 }
725 not_a_marker:
726 do {
727 ch = *src++;
728 *dst++ = ch;
729 size--;
730 } while (ch != '\n' && size);
731 }
732 result->size = dst - result->ptr;
733 return 0;
734 }
735
736 #define LL_BINARY_MERGE 0
737 #define LL_TEXT_MERGE 1
738 #define LL_UNION_MERGE 2
739 static struct ll_merge_driver ll_merge_drv[] = {
740 { "binary", "built-in binary merge", ll_binary_merge },
741 { "text", "built-in 3-way text merge", ll_xdl_merge },
742 { "union", "built-in union merge", ll_union_merge },
743 };
744
745 static void create_temp(mmfile_t *src, char *path)
746 {
747 int fd;
748
749 strcpy(path, ".merge_file_XXXXXX");
750 fd = xmkstemp(path);
751 if (write_in_full(fd, src->ptr, src->size) != src->size)
752 die("unable to write temp-file");
753 close(fd);
754 }
755
756 /*
757 * User defined low-level merge driver support.
758 */
759 static int ll_ext_merge(const struct ll_merge_driver *fn,
760 const char *path,
761 mmfile_t *orig,
762 mmfile_t *src1, const char *name1,
763 mmfile_t *src2, const char *name2,
764 mmbuffer_t *result)
765 {
766 char temp[3][50];
767 char cmdbuf[2048];
768 struct interp table[] = {
769 { "%O" },
770 { "%A" },
771 { "%B" },
772 };
773 struct child_process child;
774 const char *args[20];
775 int status, fd, i;
776 struct stat st;
777
778 if (fn->cmdline == NULL)
779 die("custom merge driver %s lacks command line.", fn->name);
780
781 result->ptr = NULL;
782 result->size = 0;
783 create_temp(orig, temp[0]);
784 create_temp(src1, temp[1]);
785 create_temp(src2, temp[2]);
786
787 interp_set_entry(table, 0, temp[0]);
788 interp_set_entry(table, 1, temp[1]);
789 interp_set_entry(table, 2, temp[2]);
790
791 output(1, "merging %s using %s", path,
792 fn->description ? fn->description : fn->name);
793
794 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
795
796 memset(&child, 0, sizeof(child));
797 child.argv = args;
798 args[0] = "sh";
799 args[1] = "-c";
800 args[2] = cmdbuf;
801 args[3] = NULL;
802
803 status = run_command(&child);
804 if (status < -ERR_RUN_COMMAND_FORK)
805 ; /* failure in run-command */
806 else
807 status = -status;
808 fd = open(temp[1], O_RDONLY);
809 if (fd < 0)
810 goto bad;
811 if (fstat(fd, &st))
812 goto close_bad;
813 result->size = st.st_size;
814 result->ptr = xmalloc(result->size + 1);
815 if (read_in_full(fd, result->ptr, result->size) != result->size) {
816 free(result->ptr);
817 result->ptr = NULL;
818 result->size = 0;
819 }
820 close_bad:
821 close(fd);
822 bad:
823 for (i = 0; i < 3; i++)
824 unlink(temp[i]);
825 return status;
826 }
827
828 /*
829 * merge.default and merge.driver configuration items
830 */
831 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
832 static const char *default_ll_merge;
833
834 static int read_merge_config(const char *var, const char *value)
835 {
836 struct ll_merge_driver *fn;
837 const char *ep, *name;
838 int namelen;
839
840 if (!strcmp(var, "merge.default")) {
841 if (value)
842 default_ll_merge = strdup(value);
843 return 0;
844 }
845
846 /*
847 * We are not interested in anything but "merge.<name>.variable";
848 * especially, we do not want to look at variables such as
849 * "merge.summary", "merge.tool", and "merge.verbosity".
850 */
851 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
852 return 0;
853
854 /*
855 * Find existing one as we might be processing merge.<name>.var2
856 * after seeing merge.<name>.var1.
857 */
858 name = var + 6;
859 namelen = ep - name;
860 for (fn = ll_user_merge; fn; fn = fn->next)
861 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
862 break;
863 if (!fn) {
864 fn = xcalloc(1, sizeof(struct ll_merge_driver));
865 fn->name = xmemdupz(name, namelen);
866 fn->fn = ll_ext_merge;
867 *ll_user_merge_tail = fn;
868 ll_user_merge_tail = &(fn->next);
869 }
870
871 ep++;
872
873 if (!strcmp("name", ep)) {
874 if (!value)
875 return error("%s: lacks value", var);
876 fn->description = strdup(value);
877 return 0;
878 }
879
880 if (!strcmp("driver", ep)) {
881 if (!value)
882 return error("%s: lacks value", var);
883 /*
884 * merge.<name>.driver specifies the command line:
885 *
886 * command-line
887 *
888 * The command-line will be interpolated with the following
889 * tokens and is given to the shell:
890 *
891 * %O - temporary file name for the merge base.
892 * %A - temporary file name for our version.
893 * %B - temporary file name for the other branches' version.
894 *
895 * The external merge driver should write the results in the
896 * file named by %A, and signal that it has done with zero exit
897 * status.
898 */
899 fn->cmdline = strdup(value);
900 return 0;
901 }
902
903 if (!strcmp("recursive", ep)) {
904 if (!value)
905 return error("%s: lacks value", var);
906 fn->recursive = strdup(value);
907 return 0;
908 }
909
910 return 0;
911 }
912
913 static void initialize_ll_merge(void)
914 {
915 if (ll_user_merge_tail)
916 return;
917 ll_user_merge_tail = &ll_user_merge;
918 git_config(read_merge_config);
919 }
920
921 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
922 {
923 struct ll_merge_driver *fn;
924 const char *name;
925 int i;
926
927 initialize_ll_merge();
928
929 if (ATTR_TRUE(merge_attr))
930 return &ll_merge_drv[LL_TEXT_MERGE];
931 else if (ATTR_FALSE(merge_attr))
932 return &ll_merge_drv[LL_BINARY_MERGE];
933 else if (ATTR_UNSET(merge_attr)) {
934 if (!default_ll_merge)
935 return &ll_merge_drv[LL_TEXT_MERGE];
936 else
937 name = default_ll_merge;
938 }
939 else
940 name = merge_attr;
941
942 for (fn = ll_user_merge; fn; fn = fn->next)
943 if (!strcmp(fn->name, name))
944 return fn;
945
946 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
947 if (!strcmp(ll_merge_drv[i].name, name))
948 return &ll_merge_drv[i];
949
950 /* default to the 3-way */
951 return &ll_merge_drv[LL_TEXT_MERGE];
952 }
953
954 static const char *git_path_check_merge(const char *path)
955 {
956 static struct git_attr_check attr_merge_check;
957
958 if (!attr_merge_check.attr)
959 attr_merge_check.attr = git_attr("merge", 5);
960
961 if (git_checkattr(path, 1, &attr_merge_check))
962 return NULL;
963 return attr_merge_check.value;
964 }
965
966 static int ll_merge(mmbuffer_t *result_buf,
967 struct diff_filespec *o,
968 struct diff_filespec *a,
969 struct diff_filespec *b,
970 const char *branch1,
971 const char *branch2)
972 {
973 mmfile_t orig, src1, src2;
974 char *name1, *name2;
975 int merge_status;
976 const char *ll_driver_name;
977 const struct ll_merge_driver *driver;
978
979 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
980 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
981
982 fill_mm(o->sha1, &orig);
983 fill_mm(a->sha1, &src1);
984 fill_mm(b->sha1, &src2);
985
986 ll_driver_name = git_path_check_merge(a->path);
987 driver = find_ll_merge_driver(ll_driver_name);
988
989 if (index_only && driver->recursive)
990 driver = find_ll_merge_driver(driver->recursive);
991 merge_status = driver->fn(driver, a->path,
992 &orig, &src1, name1, &src2, name2,
993 result_buf);
994
995 free(name1);
996 free(name2);
997 free(orig.ptr);
998 free(src1.ptr);
999 free(src2.ptr);
1000 return merge_status;
1001 }
1002
1003 static struct merge_file_info merge_file(struct diff_filespec *o,
1004 struct diff_filespec *a, struct diff_filespec *b,
1005 const char *branch1, const char *branch2)
1006 {
1007 struct merge_file_info result;
1008 result.merge = 0;
1009 result.clean = 1;
1010
1011 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1012 result.clean = 0;
1013 if (S_ISREG(a->mode)) {
1014 result.mode = a->mode;
1015 hashcpy(result.sha, a->sha1);
1016 } else {
1017 result.mode = b->mode;
1018 hashcpy(result.sha, b->sha1);
1019 }
1020 } else {
1021 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1022 result.merge = 1;
1023
1024 result.mode = a->mode == o->mode ? b->mode: a->mode;
1025
1026 if (sha_eq(a->sha1, o->sha1))
1027 hashcpy(result.sha, b->sha1);
1028 else if (sha_eq(b->sha1, o->sha1))
1029 hashcpy(result.sha, a->sha1);
1030 else if (S_ISREG(a->mode)) {
1031 mmbuffer_t result_buf;
1032 int merge_status;
1033
1034 merge_status = ll_merge(&result_buf, o, a, b,
1035 branch1, branch2);
1036
1037 if ((merge_status < 0) || !result_buf.ptr)
1038 die("Failed to execute internal merge");
1039
1040 if (write_sha1_file(result_buf.ptr, result_buf.size,
1041 blob_type, result.sha))
1042 die("Unable to add %s to database",
1043 a->path);
1044
1045 free(result_buf.ptr);
1046 result.clean = (merge_status == 0);
1047 } else {
1048 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1049 die("cannot merge modes?");
1050
1051 hashcpy(result.sha, a->sha1);
1052
1053 if (!sha_eq(a->sha1, b->sha1))
1054 result.clean = 0;
1055 }
1056 }
1057
1058 return result;
1059 }
1060
1061 static void conflict_rename_rename(struct rename *ren1,
1062 const char *branch1,
1063 struct rename *ren2,
1064 const char *branch2)
1065 {
1066 char *del[2];
1067 int delp = 0;
1068 const char *ren1_dst = ren1->pair->two->path;
1069 const char *ren2_dst = ren2->pair->two->path;
1070 const char *dst_name1 = ren1_dst;
1071 const char *dst_name2 = ren2_dst;
1072 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1073 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1074 output(1, "%s is a directory in %s added as %s instead",
1075 ren1_dst, branch2, dst_name1);
1076 remove_file(0, ren1_dst, 0);
1077 }
1078 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1079 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1080 output(1, "%s is a directory in %s added as %s instead",
1081 ren2_dst, branch1, dst_name2);
1082 remove_file(0, ren2_dst, 0);
1083 }
1084 if (index_only) {
1085 remove_file_from_cache(dst_name1);
1086 remove_file_from_cache(dst_name2);
1087 /*
1088 * Uncomment to leave the conflicting names in the resulting tree
1089 *
1090 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1091 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1092 */
1093 } else {
1094 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1095 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1096 }
1097 while (delp--)
1098 free(del[delp]);
1099 }
1100
1101 static void conflict_rename_dir(struct rename *ren1,
1102 const char *branch1)
1103 {
1104 char *new_path = unique_path(ren1->pair->two->path, branch1);
1105 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1106 remove_file(0, ren1->pair->two->path, 0);
1107 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1108 free(new_path);
1109 }
1110
1111 static void conflict_rename_rename_2(struct rename *ren1,
1112 const char *branch1,
1113 struct rename *ren2,
1114 const char *branch2)
1115 {
1116 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1117 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1118 output(1, "Renamed %s to %s and %s to %s instead",
1119 ren1->pair->one->path, new_path1,
1120 ren2->pair->one->path, new_path2);
1121 remove_file(0, ren1->pair->two->path, 0);
1122 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1123 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1124 free(new_path2);
1125 free(new_path1);
1126 }
1127
1128 static int process_renames(struct path_list *a_renames,
1129 struct path_list *b_renames,
1130 const char *a_branch,
1131 const char *b_branch)
1132 {
1133 int clean_merge = 1, i, j;
1134 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1135 const struct rename *sre;
1136
1137 for (i = 0; i < a_renames->nr; i++) {
1138 sre = a_renames->items[i].util;
1139 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1140 = sre->dst_entry;
1141 }
1142 for (i = 0; i < b_renames->nr; i++) {
1143 sre = b_renames->items[i].util;
1144 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1145 = sre->dst_entry;
1146 }
1147
1148 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1149 int compare;
1150 char *src;
1151 struct path_list *renames1, *renames2, *renames2Dst;
1152 struct rename *ren1 = NULL, *ren2 = NULL;
1153 const char *branch1, *branch2;
1154 const char *ren1_src, *ren1_dst;
1155
1156 if (i >= a_renames->nr) {
1157 compare = 1;
1158 ren2 = b_renames->items[j++].util;
1159 } else if (j >= b_renames->nr) {
1160 compare = -1;
1161 ren1 = a_renames->items[i++].util;
1162 } else {
1163 compare = strcmp(a_renames->items[i].path,
1164 b_renames->items[j].path);
1165 if (compare <= 0)
1166 ren1 = a_renames->items[i++].util;
1167 if (compare >= 0)
1168 ren2 = b_renames->items[j++].util;
1169 }
1170
1171 /* TODO: refactor, so that 1/2 are not needed */
1172 if (ren1) {
1173 renames1 = a_renames;
1174 renames2 = b_renames;
1175 renames2Dst = &b_by_dst;
1176 branch1 = a_branch;
1177 branch2 = b_branch;
1178 } else {
1179 struct rename *tmp;
1180 renames1 = b_renames;
1181 renames2 = a_renames;
1182 renames2Dst = &a_by_dst;
1183 branch1 = b_branch;
1184 branch2 = a_branch;
1185 tmp = ren2;
1186 ren2 = ren1;
1187 ren1 = tmp;
1188 }
1189 src = ren1->pair->one->path;
1190
1191 ren1->dst_entry->processed = 1;
1192 ren1->src_entry->processed = 1;
1193
1194 if (ren1->processed)
1195 continue;
1196 ren1->processed = 1;
1197
1198 ren1_src = ren1->pair->one->path;
1199 ren1_dst = ren1->pair->two->path;
1200
1201 if (ren2) {
1202 const char *ren2_src = ren2->pair->one->path;
1203 const char *ren2_dst = ren2->pair->two->path;
1204 /* Renamed in 1 and renamed in 2 */
1205 if (strcmp(ren1_src, ren2_src) != 0)
1206 die("ren1.src != ren2.src");
1207 ren2->dst_entry->processed = 1;
1208 ren2->processed = 1;
1209 if (strcmp(ren1_dst, ren2_dst) != 0) {
1210 clean_merge = 0;
1211 output(1, "CONFLICT (rename/rename): "
1212 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1213 "rename \"%s\"->\"%s\" in \"%s\"%s",
1214 src, ren1_dst, branch1,
1215 src, ren2_dst, branch2,
1216 index_only ? " (left unresolved)": "");
1217 if (index_only) {
1218 remove_file_from_cache(src);
1219 update_file(0, ren1->pair->one->sha1,
1220 ren1->pair->one->mode, src);
1221 }
1222 conflict_rename_rename(ren1, branch1, ren2, branch2);
1223 } else {
1224 struct merge_file_info mfi;
1225 remove_file(1, ren1_src, 1);
1226 mfi = merge_file(ren1->pair->one,
1227 ren1->pair->two,
1228 ren2->pair->two,
1229 branch1,
1230 branch2);
1231 if (mfi.merge || !mfi.clean)
1232 output(1, "Renamed %s->%s", src, ren1_dst);
1233
1234 if (mfi.merge)
1235 output(2, "Auto-merged %s", ren1_dst);
1236
1237 if (!mfi.clean) {
1238 output(1, "CONFLICT (content): merge conflict in %s",
1239 ren1_dst);
1240 clean_merge = 0;
1241
1242 if (!index_only)
1243 update_stages(ren1_dst,
1244 ren1->pair->one,
1245 ren1->pair->two,
1246 ren2->pair->two,
1247 1 /* clear */);
1248 }
1249 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1250 }
1251 } else {
1252 /* Renamed in 1, maybe changed in 2 */
1253 struct path_list_item *item;
1254 /* we only use sha1 and mode of these */
1255 struct diff_filespec src_other, dst_other;
1256 int try_merge, stage = a_renames == renames1 ? 3: 2;
1257
1258 remove_file(1, ren1_src, index_only || stage == 3);
1259
1260 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1261 src_other.mode = ren1->src_entry->stages[stage].mode;
1262 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1263 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1264
1265 try_merge = 0;
1266
1267 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1268 clean_merge = 0;
1269 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1270 " directory %s added in %s",
1271 ren1_src, ren1_dst, branch1,
1272 ren1_dst, branch2);
1273 conflict_rename_dir(ren1, branch1);
1274 } else if (sha_eq(src_other.sha1, null_sha1)) {
1275 clean_merge = 0;
1276 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1277 "and deleted in %s",
1278 ren1_src, ren1_dst, branch1,
1279 branch2);
1280 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1281 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1282 const char *new_path;
1283 clean_merge = 0;
1284 try_merge = 1;
1285 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1286 "%s added in %s",
1287 ren1_src, ren1_dst, branch1,
1288 ren1_dst, branch2);
1289 new_path = unique_path(ren1_dst, branch2);
1290 output(1, "Added as %s instead", new_path);
1291 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1292 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1293 ren2 = item->util;
1294 clean_merge = 0;
1295 ren2->processed = 1;
1296 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1297 "Renamed %s->%s in %s",
1298 ren1_src, ren1_dst, branch1,
1299 ren2->pair->one->path, ren2->pair->two->path, branch2);
1300 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1301 } else
1302 try_merge = 1;
1303
1304 if (try_merge) {
1305 struct diff_filespec *o, *a, *b;
1306 struct merge_file_info mfi;
1307 src_other.path = (char *)ren1_src;
1308
1309 o = ren1->pair->one;
1310 if (a_renames == renames1) {
1311 a = ren1->pair->two;
1312 b = &src_other;
1313 } else {
1314 b = ren1->pair->two;
1315 a = &src_other;
1316 }
1317 mfi = merge_file(o, a, b,
1318 a_branch, b_branch);
1319
1320 if (mfi.clean &&
1321 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1322 mfi.mode == ren1->pair->two->mode)
1323 /*
1324 * This messaged is part of
1325 * t6022 test. If you change
1326 * it update the test too.
1327 */
1328 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1329 else {
1330 if (mfi.merge || !mfi.clean)
1331 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1332 if (mfi.merge)
1333 output(2, "Auto-merged %s", ren1_dst);
1334 if (!mfi.clean) {
1335 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1336 ren1_dst);
1337 clean_merge = 0;
1338
1339 if (!index_only)
1340 update_stages(ren1_dst,
1341 o, a, b, 1);
1342 }
1343 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1344 }
1345 }
1346 }
1347 }
1348 path_list_clear(&a_by_dst, 0);
1349 path_list_clear(&b_by_dst, 0);
1350
1351 return clean_merge;
1352 }
1353
1354 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1355 {
1356 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1357 }
1358
1359 /* Per entry merge function */
1360 static int process_entry(const char *path, struct stage_data *entry,
1361 const char *branch1,
1362 const char *branch2)
1363 {
1364 /*
1365 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1366 print_index_entry("\tpath: ", entry);
1367 */
1368 int clean_merge = 1;
1369 unsigned o_mode = entry->stages[1].mode;
1370 unsigned a_mode = entry->stages[2].mode;
1371 unsigned b_mode = entry->stages[3].mode;
1372 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1373 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1374 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1375
1376 if (o_sha && (!a_sha || !b_sha)) {
1377 /* Case A: Deleted in one */
1378 if ((!a_sha && !b_sha) ||
1379 (sha_eq(a_sha, o_sha) && !b_sha) ||
1380 (!a_sha && sha_eq(b_sha, o_sha))) {
1381 /* Deleted in both or deleted in one and
1382 * unchanged in the other */
1383 if (a_sha)
1384 output(2, "Removed %s", path);
1385 /* do not touch working file if it did not exist */
1386 remove_file(1, path, !a_sha);
1387 } else {
1388 /* Deleted in one and changed in the other */
1389 clean_merge = 0;
1390 if (!a_sha) {
1391 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1392 "and modified in %s. Version %s of %s left in tree.",
1393 path, branch1,
1394 branch2, branch2, path);
1395 update_file(0, b_sha, b_mode, path);
1396 } else {
1397 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1398 "and modified in %s. Version %s of %s left in tree.",
1399 path, branch2,
1400 branch1, branch1, path);
1401 update_file(0, a_sha, a_mode, path);
1402 }
1403 }
1404
1405 } else if ((!o_sha && a_sha && !b_sha) ||
1406 (!o_sha && !a_sha && b_sha)) {
1407 /* Case B: Added in one. */
1408 const char *add_branch;
1409 const char *other_branch;
1410 unsigned mode;
1411 const unsigned char *sha;
1412 const char *conf;
1413
1414 if (a_sha) {
1415 add_branch = branch1;
1416 other_branch = branch2;
1417 mode = a_mode;
1418 sha = a_sha;
1419 conf = "file/directory";
1420 } else {
1421 add_branch = branch2;
1422 other_branch = branch1;
1423 mode = b_mode;
1424 sha = b_sha;
1425 conf = "directory/file";
1426 }
1427 if (path_list_has_path(&current_directory_set, path)) {
1428 const char *new_path = unique_path(path, add_branch);
1429 clean_merge = 0;
1430 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1431 "Added %s as %s",
1432 conf, path, other_branch, path, new_path);
1433 remove_file(0, path, 0);
1434 update_file(0, sha, mode, new_path);
1435 } else {
1436 output(2, "Added %s", path);
1437 update_file(1, sha, mode, path);
1438 }
1439 } else if (a_sha && b_sha) {
1440 /* Case C: Added in both (check for same permissions) and */
1441 /* case D: Modified in both, but differently. */
1442 const char *reason = "content";
1443 struct merge_file_info mfi;
1444 struct diff_filespec o, a, b;
1445
1446 if (!o_sha) {
1447 reason = "add/add";
1448 o_sha = (unsigned char *)null_sha1;
1449 }
1450 output(2, "Auto-merged %s", path);
1451 o.path = a.path = b.path = (char *)path;
1452 hashcpy(o.sha1, o_sha);
1453 o.mode = o_mode;
1454 hashcpy(a.sha1, a_sha);
1455 a.mode = a_mode;
1456 hashcpy(b.sha1, b_sha);
1457 b.mode = b_mode;
1458
1459 mfi = merge_file(&o, &a, &b,
1460 branch1, branch2);
1461
1462 if (mfi.clean)
1463 update_file(1, mfi.sha, mfi.mode, path);
1464 else {
1465 clean_merge = 0;
1466 output(1, "CONFLICT (%s): Merge conflict in %s",
1467 reason, path);
1468
1469 if (index_only)
1470 update_file(0, mfi.sha, mfi.mode, path);
1471 else
1472 update_file_flags(mfi.sha, mfi.mode, path,
1473 0 /* update_cache */, 1 /* update_working_directory */);
1474 }
1475 } else if (!o_sha && !a_sha && !b_sha) {
1476 /*
1477 * this entry was deleted altogether. a_mode == 0 means
1478 * we had that path and want to actively remove it.
1479 */
1480 remove_file(1, path, !a_mode);
1481 } else
1482 die("Fatal merge failure, shouldn't happen.");
1483
1484 return clean_merge;
1485 }
1486
1487 static int merge_trees(struct tree *head,
1488 struct tree *merge,
1489 struct tree *common,
1490 const char *branch1,
1491 const char *branch2,
1492 struct tree **result)
1493 {
1494 int code, clean;
1495
1496 if (subtree_merge) {
1497 merge = shift_tree_object(head, merge);
1498 common = shift_tree_object(head, common);
1499 }
1500
1501 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1502 output(0, "Already uptodate!");
1503 *result = head;
1504 return 1;
1505 }
1506
1507 code = git_merge_trees(index_only, common, head, merge);
1508
1509 if (code != 0)
1510 die("merging of trees %s and %s failed",
1511 sha1_to_hex(head->object.sha1),
1512 sha1_to_hex(merge->object.sha1));
1513
1514 if (unmerged_index()) {
1515 struct path_list *entries, *re_head, *re_merge;
1516 int i;
1517 path_list_clear(&current_file_set, 1);
1518 path_list_clear(&current_directory_set, 1);
1519 get_files_dirs(head);
1520 get_files_dirs(merge);
1521
1522 entries = get_unmerged();
1523 re_head = get_renames(head, common, head, merge, entries);
1524 re_merge = get_renames(merge, common, head, merge, entries);
1525 clean = process_renames(re_head, re_merge,
1526 branch1, branch2);
1527 for (i = 0; i < entries->nr; i++) {
1528 const char *path = entries->items[i].path;
1529 struct stage_data *e = entries->items[i].util;
1530 if (!e->processed
1531 && !process_entry(path, e, branch1, branch2))
1532 clean = 0;
1533 }
1534
1535 path_list_clear(re_merge, 0);
1536 path_list_clear(re_head, 0);
1537 path_list_clear(entries, 1);
1538
1539 }
1540 else
1541 clean = 1;
1542
1543 if (index_only)
1544 *result = git_write_tree();
1545
1546 return clean;
1547 }
1548
1549 static struct commit_list *reverse_commit_list(struct commit_list *list)
1550 {
1551 struct commit_list *next = NULL, *current, *backup;
1552 for (current = list; current; current = backup) {
1553 backup = current->next;
1554 current->next = next;
1555 next = current;
1556 }
1557 return next;
1558 }
1559
1560 /*
1561 * Merge the commits h1 and h2, return the resulting virtual
1562 * commit object and a flag indicating the cleanness of the merge.
1563 */
1564 static int merge(struct commit *h1,
1565 struct commit *h2,
1566 const char *branch1,
1567 const char *branch2,
1568 struct commit_list *ca,
1569 struct commit **result)
1570 {
1571 struct commit_list *iter;
1572 struct commit *merged_common_ancestors;
1573 struct tree *mrtree;
1574 int clean;
1575
1576 if (show(4)) {
1577 output(4, "Merging:");
1578 output_commit_title(h1);
1579 output_commit_title(h2);
1580 }
1581
1582 if (!ca) {
1583 ca = get_merge_bases(h1, h2, 1);
1584 ca = reverse_commit_list(ca);
1585 }
1586
1587 if (show(5)) {
1588 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1589 for (iter = ca; iter; iter = iter->next)
1590 output_commit_title(iter->item);
1591 }
1592
1593 merged_common_ancestors = pop_commit(&ca);
1594 if (merged_common_ancestors == NULL) {
1595 /* if there is no common ancestor, make an empty tree */
1596 struct tree *tree = xcalloc(1, sizeof(struct tree));
1597
1598 tree->object.parsed = 1;
1599 tree->object.type = OBJ_TREE;
1600 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1601 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1602 }
1603
1604 for (iter = ca; iter; iter = iter->next) {
1605 call_depth++;
1606 /*
1607 * When the merge fails, the result contains files
1608 * with conflict markers. The cleanness flag is
1609 * ignored, it was never actually used, as result of
1610 * merge_trees has always overwritten it: the committed
1611 * "conflicts" were already resolved.
1612 */
1613 discard_cache();
1614 merge(merged_common_ancestors, iter->item,
1615 "Temporary merge branch 1",
1616 "Temporary merge branch 2",
1617 NULL,
1618 &merged_common_ancestors);
1619 call_depth--;
1620
1621 if (!merged_common_ancestors)
1622 die("merge returned no commit");
1623 }
1624
1625 discard_cache();
1626 if (!call_depth) {
1627 read_cache();
1628 index_only = 0;
1629 } else
1630 index_only = 1;
1631
1632 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1633 branch1, branch2, &mrtree);
1634
1635 if (index_only) {
1636 *result = make_virtual_commit(mrtree, "merged tree");
1637 commit_list_insert(h1, &(*result)->parents);
1638 commit_list_insert(h2, &(*result)->parents->next);
1639 }
1640 flush_output();
1641 return clean;
1642 }
1643
1644 static const char *better_branch_name(const char *branch)
1645 {
1646 static char githead_env[8 + 40 + 1];
1647 char *name;
1648
1649 if (strlen(branch) != 40)
1650 return branch;
1651 sprintf(githead_env, "GITHEAD_%s", branch);
1652 name = getenv(githead_env);
1653 return name ? name : branch;
1654 }
1655
1656 static struct commit *get_ref(const char *ref)
1657 {
1658 unsigned char sha1[20];
1659 struct object *object;
1660
1661 if (get_sha1(ref, sha1))
1662 die("Could not resolve ref '%s'", ref);
1663 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1664 if (object->type == OBJ_TREE)
1665 return make_virtual_commit((struct tree*)object,
1666 better_branch_name(ref));
1667 if (object->type != OBJ_COMMIT)
1668 return NULL;
1669 if (parse_commit((struct commit *)object))
1670 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1671 return (struct commit *)object;
1672 }
1673
1674 static int merge_config(const char *var, const char *value)
1675 {
1676 if (!strcasecmp(var, "merge.verbosity")) {
1677 verbosity = git_config_int(var, value);
1678 return 0;
1679 }
1680 return git_default_config(var, value);
1681 }
1682
1683 int main(int argc, char *argv[])
1684 {
1685 static const char *bases[20];
1686 static unsigned bases_count = 0;
1687 int i, clean;
1688 const char *branch1, *branch2;
1689 struct commit *result, *h1, *h2;
1690 struct commit_list *ca = NULL;
1691 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1692 int index_fd;
1693
1694 if (argv[0]) {
1695 int namelen = strlen(argv[0]);
1696 if (8 < namelen &&
1697 !strcmp(argv[0] + namelen - 8, "-subtree"))
1698 subtree_merge = 1;
1699 }
1700
1701 git_config(merge_config);
1702 if (getenv("GIT_MERGE_VERBOSITY"))
1703 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1704
1705 if (argc < 4)
1706 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1707
1708 for (i = 1; i < argc; ++i) {
1709 if (!strcmp(argv[i], "--"))
1710 break;
1711 if (bases_count < sizeof(bases)/sizeof(*bases))
1712 bases[bases_count++] = argv[i];
1713 }
1714 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1715 die("Not handling anything other than two heads merge.");
1716 if (verbosity >= 5)
1717 buffer_output = 0;
1718
1719 branch1 = argv[++i];
1720 branch2 = argv[++i];
1721
1722 h1 = get_ref(branch1);
1723 h2 = get_ref(branch2);
1724
1725 branch1 = better_branch_name(branch1);
1726 branch2 = better_branch_name(branch2);
1727
1728 if (show(3))
1729 printf("Merging %s with %s\n", branch1, branch2);
1730
1731 index_fd = hold_locked_index(lock, 1);
1732
1733 for (i = 0; i < bases_count; i++) {
1734 struct commit *ancestor = get_ref(bases[i]);
1735 ca = commit_list_insert(ancestor, &ca);
1736 }
1737 clean = merge(h1, h2, branch1, branch2, ca, &result);
1738
1739 if (active_cache_changed &&
1740 (write_cache(index_fd, active_cache, active_nr) ||
1741 close(index_fd) || commit_locked_index(lock)))
1742 die ("unable to write %s", get_index_file());
1743
1744 return clean ? 0: 1;
1745 }
Jonathan Nieder’s miscellaneous git branches