stash: make sure to write refreshed cache
[git/git.git] / diffcore-rename.c
CommitLineData
427dcb4b
JH
1/*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4#include "cache.h"
5#include "diff.h"
6#include "diffcore.h"
cbd53a21 7#include "object-store.h"
f79d9c58 8#include "hashmap.h"
3ac942d4 9#include "progress.h"
427dcb4b 10
25d5ea41
JH
11/* Table of rename/copy destinations */
12
13static struct diff_rename_dst {
14 struct diff_filespec *two;
15 struct diff_filepair *pair;
16} *rename_dst;
17static int rename_dst_nr, rename_dst_alloc;
427dcb4b 18
f98c2f7e 19static int find_rename_dst(struct diff_filespec *two)
427dcb4b 20{
25d5ea41
JH
21 int first, last;
22
23 first = 0;
24 last = rename_dst_nr;
25 while (last > first) {
568a05c5 26 int next = first + ((last - first) >> 1);
25d5ea41
JH
27 struct diff_rename_dst *dst = &(rename_dst[next]);
28 int cmp = strcmp(two->path, dst->two->path);
29 if (!cmp)
f98c2f7e 30 return next;
25d5ea41
JH
31 if (cmp < 0) {
32 last = next;
33 continue;
34 }
35 first = next+1;
36 }
f98c2f7e
JK
37 return -first - 1;
38}
39
40static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two)
41{
42 int ofs = find_rename_dst(two);
43 return ofs < 0 ? NULL : &rename_dst[ofs];
44}
45
46/*
47 * Returns 0 on success, -1 if we found a duplicate.
48 */
49static int add_rename_dst(struct diff_filespec *two)
50{
51 int first = find_rename_dst(two);
52
53 if (first >= 0)
54 return -1;
55 first = -first - 1;
56
25d5ea41 57 /* insert to make it at "first" */
337ce247 58 ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc);
25d5ea41
JH
59 rename_dst_nr++;
60 if (first < rename_dst_nr)
f919ffeb
SG
61 MOVE_ARRAY(rename_dst + first + 1, rename_dst + first,
62 rename_dst_nr - first - 1);
5098bafb 63 rename_dst[first].two = alloc_filespec(two->path);
f9704c2d 64 fill_filespec(rename_dst[first].two, &two->oid, two->oid_valid,
a0d12c44 65 two->mode);
25d5ea41 66 rename_dst[first].pair = NULL;
f98c2f7e 67 return 0;
427dcb4b
JH
68}
69
15d061b4 70/* Table of rename/copy src files */
25d5ea41 71static struct diff_rename_src {
e88d6bc6 72 struct diff_filepair *p;
fc580719 73 unsigned short score; /* to remember the break score */
25d5ea41
JH
74} *rename_src;
75static int rename_src_nr, rename_src_alloc;
427dcb4b 76
e88d6bc6 77static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
25d5ea41
JH
78{
79 int first, last;
e88d6bc6
JH
80 struct diff_filespec *one = p->one;
81 unsigned short score = p->score;
25d5ea41
JH
82
83 first = 0;
84 last = rename_src_nr;
85 while (last > first) {
568a05c5 86 int next = first + ((last - first) >> 1);
25d5ea41 87 struct diff_rename_src *src = &(rename_src[next]);
e88d6bc6 88 int cmp = strcmp(one->path, src->p->one->path);
25d5ea41
JH
89 if (!cmp)
90 return src;
91 if (cmp < 0) {
92 last = next;
93 continue;
94 }
95 first = next+1;
96 }
15d061b4 97
25d5ea41 98 /* insert to make it at "first" */
337ce247 99 ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc);
25d5ea41
JH
100 rename_src_nr++;
101 if (first < rename_src_nr)
f919ffeb
SG
102 MOVE_ARRAY(rename_src + first + 1, rename_src + first,
103 rename_src_nr - first - 1);
e88d6bc6 104 rename_src[first].p = p;
fc580719 105 rename_src[first].score = score;
25d5ea41 106 return &(rename_src[first]);
427dcb4b
JH
107}
108
0ce39643
JS
109static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
110{
111 int src_len = strlen(src->path), dst_len = strlen(dst->path);
112 while (src_len && dst_len) {
113 char c1 = src->path[--src_len];
114 char c2 = dst->path[--dst_len];
115 if (c1 != c2)
116 return 0;
117 if (c1 == '/')
118 return 1;
119 }
120 return (!src_len || src->path[src_len - 1] == '/') &&
121 (!dst_len || dst->path[dst_len - 1] == '/');
122}
123
427dcb4b 124struct diff_score {
25d5ea41
JH
125 int src; /* index in rename_src */
126 int dst; /* index in rename_dst */
6d24ad97
JH
127 unsigned short score;
128 short name_score;
427dcb4b
JH
129};
130
b78ea5fc
NTND
131static int estimate_similarity(struct repository *r,
132 struct diff_filespec *src,
427dcb4b
JH
133 struct diff_filespec *dst,
134 int minimum_score)
135{
136 /* src points at a file that existed in the original tree (or
137 * optionally a file in the destination tree) and dst points
138 * at a newly created file. They may be quite similar, in which
139 * case we want to say src is renamed to dst or src is copied into
140 * dst, and then some edit has been applied to dst.
141 *
142 * Compare them and return how similar they are, representing
f0c6b2a2
JH
143 * the score as an integer between 0 and MAX_SCORE.
144 *
145 * When there is an exact match, it is considered a better
146 * match than anything else; the destination does not even
147 * call into this function in that case.
427dcb4b 148 */
90bd932c 149 unsigned long max_size, delta_size, base_size, src_copied, literal_added;
427dcb4b
JH
150 int score;
151
60896c7b
JH
152 /* We deal only with regular files. Symlink renames are handled
153 * only when they are exact matches --- in other words, no edits
154 * after renaming.
155 */
156 if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
157 return 0;
158
81ac051d
LT
159 /*
160 * Need to check that source and destination sizes are
161 * filled in before comparing them.
162 *
163 * If we already have "cnt_data" filled in, we know it's
164 * all good (avoid checking the size for zero, as that
165 * is a possible size - we really should have a flag to
166 * say whether the size is valid or not!)
167 */
8e5dd3d6 168 if (!src->cnt_data &&
b78ea5fc 169 diff_populate_filespec(r, src, CHECK_SIZE_ONLY))
81ac051d 170 return 0;
8e5dd3d6 171 if (!dst->cnt_data &&
b78ea5fc 172 diff_populate_filespec(r, dst, CHECK_SIZE_ONLY))
81ac051d
LT
173 return 0;
174
90bd932c 175 max_size = ((src->size > dst->size) ? src->size : dst->size);
58b103f5 176 base_size = ((src->size < dst->size) ? src->size : dst->size);
90bd932c 177 delta_size = max_size - base_size;
427dcb4b 178
58b103f5
JH
179 /* We would not consider edits that change the file size so
180 * drastically. delta_size must be smaller than
cd1870ed 181 * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
f0c6b2a2 182 *
58b103f5
JH
183 * Note that base_size == 0 case is handled here already
184 * and the final score computation below would not have a
185 * divide-by-zero issue.
427dcb4b 186 */
3a4d6769 187 if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
427dcb4b
JH
188 return 0;
189
b78ea5fc 190 if (!src->cnt_data && diff_populate_filespec(r, src, 0))
885c716f 191 return 0;
b78ea5fc 192 if (!dst->cnt_data && diff_populate_filespec(r, dst, 0))
885c716f
BS
193 return 0;
194
b78ea5fc 195 if (diffcore_count_changes(r, src, dst,
c06c7966 196 &src->cnt_data, &dst->cnt_data,
65416758 197 &src_copied, &literal_added))
85976974 198 return 0;
355e76a4 199
1706306a
JH
200 /* How similar are they?
201 * what percentage of material in dst are from source?
427dcb4b 202 */
90bd932c 203 if (!dst->size)
1706306a 204 score = 0; /* should not happen */
cfc0aef1 205 else
dc49cd76 206 score = (int)(src_copied * MAX_SCORE / max_size);
427dcb4b
JH
207 return score;
208}
209
5098bafb 210static void record_rename_pair(int dst_index, int src_index, int score)
427dcb4b 211{
9fb88419 212 struct diff_filespec *src, *dst;
25d5ea41 213 struct diff_filepair *dp;
f7c1512a 214
25d5ea41
JH
215 if (rename_dst[dst_index].pair)
216 die("internal error: dst already matched.");
427dcb4b 217
e88d6bc6 218 src = rename_src[src_index].p->one;
64479711 219 src->rename_used++;
9fb88419 220 src->count++;
427dcb4b 221
25d5ea41 222 dst = rename_dst[dst_index].two;
9fb88419 223 dst->count++;
427dcb4b 224
9fb88419 225 dp = diff_queue(NULL, src, dst);
ef677686 226 dp->renamed_pair = 1;
fc580719
JH
227 if (!strcmp(src->path, dst->path))
228 dp->score = rename_src[src_index].score;
229 else
230 dp->score = score;
25d5ea41 231 rename_dst[dst_index].pair = dp;
427dcb4b
JH
232}
233
234/*
235 * We sort the rename similarity matrix with the score, in descending
15d061b4 236 * order (the most similar first).
427dcb4b
JH
237 */
238static int score_compare(const void *a_, const void *b_)
239{
240 const struct diff_score *a = a_, *b = b_;
cfc0aef1 241
6d24ad97
JH
242 /* sink the unused ones to the bottom */
243 if (a->dst < 0)
244 return (0 <= b->dst);
245 else if (b->dst < 0)
246 return -1;
247
cfc0aef1
RS
248 if (a->score == b->score)
249 return b->name_score - a->name_score;
250
427dcb4b
JH
251 return b->score - a->score;
252}
253
9027f53c 254struct file_similarity {
f79d9c58 255 struct hashmap_entry entry;
7c85f8ac 256 int index;
9027f53c 257 struct diff_filespec *filespec;
9027f53c
LT
258};
259
b78ea5fc
NTND
260static unsigned int hash_filespec(struct repository *r,
261 struct diff_filespec *filespec)
48f6407f 262{
41c9560e 263 if (!filespec->oid_valid) {
b78ea5fc 264 if (diff_populate_filespec(r, filespec, 0))
48f6407f 265 return 0;
f070facc
PO
266 hash_object_file(filespec->data, filespec->size, "blob",
267 &filespec->oid);
48f6407f 268 }
d40abc8e 269 return oidhash(&filespec->oid);
48f6407f
KB
270}
271
f79d9c58 272static int find_identical_files(struct hashmap *srcs,
7c85f8ac 273 int dst_index,
11f944dd 274 struct diff_options *options)
9027f53c
LT
275{
276 int renames = 0;
277
7c85f8ac 278 struct diff_filespec *target = rename_dst[dst_index].two;
ab73a9d1 279 struct file_similarity *p, *best = NULL;
48f6407f
KB
280 int i = 100, best_score = -1;
281
282 /*
7c85f8ac 283 * Find the best source match for specified destination.
48f6407f 284 */
b78ea5fc
NTND
285 p = hashmap_get_from_hash(srcs,
286 hash_filespec(options->repo, target),
287 NULL);
ab73a9d1 288 for (; p; p = hashmap_get_next(srcs, p)) {
48f6407f
KB
289 int score;
290 struct diff_filespec *source = p->filespec;
291
292 /* False hash collision? */
9001dc2a 293 if (!oideq(&source->oid, &target->oid))
48f6407f
KB
294 continue;
295 /* Non-regular files? If so, the modes must match! */
296 if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
297 if (source->mode != target->mode)
0940e5f2 298 continue;
9027f53c 299 }
48f6407f
KB
300 /* Give higher scores to sources that haven't been used already */
301 score = !source->rename_used;
302 if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
303 continue;
304 score += basename_same(source, target);
305 if (score > best_score) {
306 best = p;
307 best_score = score;
308 if (score == 2)
309 break;
9027f53c 310 }
48f6407f
KB
311
312 /* Too many identical alternatives? Pick one */
313 if (!--i)
314 break;
315 }
316 if (best) {
7c85f8ac 317 record_rename_pair(dst_index, best->index, MAX_SCORE);
48f6407f
KB
318 renames++;
319 }
9027f53c
LT
320 return renames;
321}
322
b78ea5fc
NTND
323static void insert_file_table(struct repository *r,
324 struct hashmap *table, int index,
325 struct diff_filespec *filespec)
9027f53c 326{
9027f53c
LT
327 struct file_similarity *entry = xmalloc(sizeof(*entry));
328
9027f53c
LT
329 entry->index = index;
330 entry->filespec = filespec;
9027f53c 331
b78ea5fc 332 hashmap_entry_init(entry, hash_filespec(r, filespec));
f79d9c58 333 hashmap_add(table, entry);
9027f53c
LT
334}
335
cb1491b6
LT
336/*
337 * Find exact renames first.
338 *
339 * The first round matches up the up-to-date entries,
340 * and then during the second round we try to match
341 * cache-dirty entries as well.
cb1491b6 342 */
11f944dd 343static int find_exact_renames(struct diff_options *options)
cb1491b6 344{
7c85f8ac 345 int i, renames = 0;
f79d9c58 346 struct hashmap file_table;
cb1491b6 347
ca4e3ca0
SG
348 /* Add all sources to the hash table in reverse order, because
349 * later on they will be retrieved in LIFO order.
350 */
7663cdc8 351 hashmap_init(&file_table, NULL, NULL, rename_src_nr);
ca4e3ca0 352 for (i = rename_src_nr-1; i >= 0; i--)
b78ea5fc
NTND
353 insert_file_table(options->repo,
354 &file_table, i,
355 rename_src[i].p->one);
9027f53c 356
7c85f8ac 357 /* Walk the destinations and find best source match */
9027f53c 358 for (i = 0; i < rename_dst_nr; i++)
7c85f8ac 359 renames += find_identical_files(&file_table, i, options);
9027f53c 360
f79d9c58
KB
361 /* Free the hash data structure and entries */
362 hashmap_free(&file_table, 1);
9027f53c 363
7c85f8ac 364 return renames;
cb1491b6
LT
365}
366
6d24ad97
JH
367#define NUM_CANDIDATE_PER_DST 4
368static void record_if_better(struct diff_score m[], struct diff_score *o)
369{
370 int i, worst;
371
372 /* find the worst one */
373 worst = 0;
374 for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
375 if (score_compare(&m[i], &m[worst]) > 0)
376 worst = i;
377
378 /* is it better than the worst one? */
379 if (score_compare(&m[worst], o) > 0)
380 m[worst] = *o;
381}
382
f31027c9
JH
383/*
384 * Returns:
385 * 0 if we are under the limit;
386 * 1 if we need to disable inexact rename detection;
387 * 2 if we would be under the limit if we were given -C instead of -C -C.
388 */
9d8a5a50
JH
389static int too_many_rename_candidates(int num_create,
390 struct diff_options *options)
391{
392 int rename_limit = options->rename_limit;
393 int num_src = rename_src_nr;
f31027c9 394 int i;
9d8a5a50
JH
395
396 options->needed_rename_limit = 0;
397
398 /*
399 * This basically does a test for the rename matrix not
400 * growing larger than a "rename_limit" square matrix, ie:
401 *
402 * num_create * num_src > rename_limit * rename_limit
9d8a5a50 403 */
89973554
JT
404 if (rename_limit <= 0)
405 rename_limit = 32767;
9d8a5a50 406 if ((num_create <= rename_limit || num_src <= rename_limit) &&
9f7e4bfa
EN
407 ((uint64_t)num_create * (uint64_t)num_src
408 <= (uint64_t)rename_limit * (uint64_t)rename_limit))
9d8a5a50
JH
409 return 0;
410
411 options->needed_rename_limit =
412 num_src > num_create ? num_src : num_create;
f31027c9
JH
413
414 /* Are we running under -C -C? */
0d1e0e78 415 if (!options->flags.find_copies_harder)
f31027c9
JH
416 return 1;
417
418 /* Would we bust the limit if we were running under -C? */
419 for (num_src = i = 0; i < rename_src_nr; i++) {
420 if (diff_unmodified_pair(rename_src[i].p))
421 continue;
422 num_src++;
423 }
424 if ((num_create <= rename_limit || num_src <= rename_limit) &&
9f7e4bfa
EN
425 ((uint64_t)num_create * (uint64_t)num_src
426 <= (uint64_t)rename_limit * (uint64_t)rename_limit))
f31027c9 427 return 2;
9d8a5a50
JH
428 return 1;
429}
430
0940e5f2
LT
431static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
432{
433 int count = 0, i;
434
435 for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
436 struct diff_rename_dst *dst;
437
438 if ((mx[i].dst < 0) ||
439 (mx[i].score < minimum_score))
440 break; /* there is no more usable pair. */
441 dst = &rename_dst[mx[i].dst];
442 if (dst->pair)
443 continue; /* already done, either exact or fuzzy. */
e88d6bc6 444 if (!copies && rename_src[mx[i].src].p->one->rename_used)
0940e5f2
LT
445 continue;
446 record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
447 count++;
448 }
449 return count;
450}
451
8082d8d3 452void diffcore_rename(struct diff_options *options)
427dcb4b 453{
8082d8d3
JH
454 int detect_rename = options->detect_rename;
455 int minimum_score = options->rename_score;
38c6f780 456 struct diff_queue_struct *q = &diff_queued_diff;
5098bafb 457 struct diff_queue_struct outq;
427dcb4b 458 struct diff_score *mx;
f31027c9 459 int i, j, rename_count, skip_unmodified = 0;
dabdbee1 460 int num_create, dst_cnt;
3ac942d4 461 struct progress *progress = NULL;
427dcb4b 462
26dee0ad 463 if (!minimum_score)
f345b0a0 464 minimum_score = DEFAULT_RENAME_SCORE;
427dcb4b 465
427dcb4b 466 for (i = 0; i < q->nr; i++) {
52e95789 467 struct diff_filepair *p = q->queue[i];
2f3f8b21 468 if (!DIFF_FILE_VALID(p->one)) {
81e50eab 469 if (!DIFF_FILE_VALID(p->two))
60896c7b 470 continue; /* unmerged */
2f3f8b21
JH
471 else if (options->single_follow &&
472 strcmp(options->single_follow, p->two->path))
473 continue; /* not interested */
0d1e0e78 474 else if (!options->flags.rename_empty &&
02491b67 475 is_empty_blob_oid(&p->two->oid))
90d43b07 476 continue;
4d6be03b
JK
477 else if (add_rename_dst(p->two) < 0) {
478 warning("skipping rename detection, detected"
479 " duplicate destination '%s'",
480 p->two->path);
481 goto cleanup;
482 }
2f3f8b21 483 }
0d1e0e78 484 else if (!options->flags.rename_empty &&
02491b67 485 is_empty_blob_oid(&p->one->oid))
90d43b07 486 continue;
d7c9bf22 487 else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
64479711
LT
488 /*
489 * If the source is a broken "delete", and
2210100a
JH
490 * they did not really want to get broken,
491 * that means the source actually stays.
64479711
LT
492 * So we increment the "rename_used" score
493 * by one, to indicate ourselves as a user
494 */
495 if (p->broken_pair && !p->score)
496 p->one->rename_used++;
e88d6bc6 497 register_rename_src(p);
64479711
LT
498 }
499 else if (detect_rename == DIFF_DETECT_COPY) {
500 /*
501 * Increment the "rename_used" score by
502 * one, to indicate ourselves as a user.
2210100a 503 */
64479711 504 p->one->rename_used++;
e88d6bc6 505 register_rename_src(p);
2210100a 506 }
427dcb4b 507 }
0024a549 508 if (rename_dst_nr == 0 || rename_src_nr == 0)
427dcb4b
JH
509 goto cleanup; /* nothing to do */
510
17559a64
LT
511 /*
512 * We really want to cull the candidates list early
513 * with cheap tests in order to avoid doing deltas.
514 */
11f944dd 515 rename_count = find_exact_renames(options);
17559a64 516
42899ac8
LT
517 /* Did we only want exact renames? */
518 if (minimum_score == MAX_SCORE)
519 goto cleanup;
520
521 /*
522 * Calculate how many renames are left (but all the source
523 * files still remain as options for rename/copies!)
524 */
525 num_create = (rename_dst_nr - rename_count);
42899ac8
LT
526
527 /* All done? */
528 if (!num_create)
529 goto cleanup;
530
f31027c9
JH
531 switch (too_many_rename_candidates(num_create, options)) {
532 case 1:
0024a549 533 goto cleanup;
f31027c9
JH
534 case 2:
535 options->degraded_cc_to_c = 1;
536 skip_unmodified = 1;
537 break;
538 default:
539 break;
540 }
0024a549 541
3ac942d4 542 if (options->show_rename_progress) {
8aade107 543 progress = start_delayed_progress(
754dbc43 544 _("Performing inexact rename detection"),
d6861d02 545 (uint64_t)rename_dst_nr * (uint64_t)rename_src_nr);
3ac942d4
JK
546 }
547
50492f7b 548 mx = xcalloc(st_mult(NUM_CANDIDATE_PER_DST, num_create), sizeof(*mx));
25d5ea41 549 for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
25d5ea41 550 struct diff_filespec *two = rename_dst[i].two;
6d24ad97
JH
551 struct diff_score *m;
552
25d5ea41 553 if (rename_dst[i].pair)
427dcb4b 554 continue; /* dealt with exact match already. */
6d24ad97
JH
555
556 m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
557 for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
558 m[j].dst = -1;
559
25d5ea41 560 for (j = 0; j < rename_src_nr; j++) {
e88d6bc6 561 struct diff_filespec *one = rename_src[j].p->one;
6d24ad97 562 struct diff_score this_src;
f31027c9
JH
563
564 if (skip_unmodified &&
565 diff_unmodified_pair(rename_src[j].p))
566 continue;
567
b78ea5fc
NTND
568 this_src.score = estimate_similarity(options->repo,
569 one, two,
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JH
570 minimum_score);
571 this_src.name_score = basename_same(one, two);
572 this_src.dst = i;
573 this_src.src = j;
574 record_if_better(m, &this_src);
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JH
575 /*
576 * Once we run estimate_similarity,
577 * We do not need the text anymore.
578 */
8ae92e63 579 diff_free_filespec_blob(one);
809809bb 580 diff_free_filespec_blob(two);
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JH
581 }
582 dst_cnt++;
d6861d02 583 display_progress(progress, (uint64_t)(i+1)*(uint64_t)rename_src_nr);
427dcb4b 584 }
3ac942d4 585 stop_progress(&progress);
6d24ad97 586
427dcb4b 587 /* cost matrix sorted by most to least similar pair */
9ed0d8d6 588 QSORT(mx, dst_cnt * NUM_CANDIDATE_PER_DST, score_compare);
6d24ad97 589
0940e5f2
LT
590 rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
591 if (detect_rename == DIFF_DETECT_COPY)
592 rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
427dcb4b 593 free(mx);
427dcb4b 594
15d061b4 595 cleanup:
427dcb4b 596 /* At this point, we have found some renames and copies and they
5098bafb 597 * are recorded in rename_dst. The original list is still in *q.
427dcb4b 598 */
9ca5df90 599 DIFF_QUEUE_CLEAR(&outq);
427dcb4b 600 for (i = 0; i < q->nr; i++) {
25d5ea41 601 struct diff_filepair *p = q->queue[i];
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JH
602 struct diff_filepair *pair_to_free = NULL;
603
d7c9bf22
MZ
604 if (DIFF_PAIR_UNMERGED(p)) {
605 diff_q(&outq, p);
606 }
607 else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2cd68882
JH
608 /*
609 * Creation
610 *
611 * We would output this create record if it has
612 * not been turned into a rename/copy already.
613 */
f98c2f7e 614 struct diff_rename_dst *dst = locate_rename_dst(p->two);
2cd68882 615 if (dst && dst->pair) {
25d5ea41
JH
616 diff_q(&outq, dst->pair);
617 pair_to_free = p;
618 }
619 else
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JH
620 /* no matching rename/copy source, so
621 * record this as a creation.
25d5ea41
JH
622 */
623 diff_q(&outq, p);
427dcb4b 624 }
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JH
625 else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) {
626 /*
627 * Deletion
628 *
f345b0a0
JH
629 * We would output this delete record if:
630 *
631 * (1) this is a broken delete and the counterpart
632 * broken create remains in the output; or
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JH
633 * (2) this is not a broken delete, and rename_dst
634 * does not have a rename/copy to move p->one->path
635 * out of existence.
f345b0a0
JH
636 *
637 * Otherwise, the counterpart broken create
638 * has been turned into a rename-edit; or
639 * delete did not have a matching create to
640 * begin with.
2cd68882 641 */
f345b0a0
JH
642 if (DIFF_PAIR_BROKEN(p)) {
643 /* broken delete */
f98c2f7e 644 struct diff_rename_dst *dst = locate_rename_dst(p->one);
f345b0a0
JH
645 if (dst && dst->pair)
646 /* counterpart is now rename/copy */
647 pair_to_free = p;
648 }
649 else {
64479711 650 if (p->one->rename_used)
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JH
651 /* this path remains */
652 pair_to_free = p;
653 }
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JH
654
655 if (pair_to_free)
656 ;
657 else
658 diff_q(&outq, p);
659 }
25d5ea41 660 else if (!diff_unmodified_pair(p))
15d061b4 661 /* all the usual ones need to be kept */
25d5ea41 662 diff_q(&outq, p);
15d061b4
JH
663 else
664 /* no need to keep unmodified pairs */
665 pair_to_free = p;
666
226406f6
JH
667 if (pair_to_free)
668 diff_free_filepair(pair_to_free);
427dcb4b 669 }
25d5ea41 670 diff_debug_queue("done copying original", &outq);
427dcb4b 671
25d5ea41
JH
672 free(q->queue);
673 *q = outq;
674 diff_debug_queue("done collapsing", q);
427dcb4b 675
9fb88419
LT
676 for (i = 0; i < rename_dst_nr; i++)
677 free_filespec(rename_dst[i].two);
5098bafb 678
6a83d902 679 FREE_AND_NULL(rename_dst);
25d5ea41 680 rename_dst_nr = rename_dst_alloc = 0;
6a83d902 681 FREE_AND_NULL(rename_src);
25d5ea41 682 rename_src_nr = rename_src_alloc = 0;
427dcb4b
JH
683 return;
684}