read-cache.c: remove 'const' from index_has_changes()
[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) {
26 int next = (last + first) >> 1;
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) {
86 int next = (last + first) >> 1;
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
131static int estimate_similarity(struct diff_filespec *src,
132 struct diff_filespec *dst,
133 int minimum_score)
134{
135 /* src points at a file that existed in the original tree (or
136 * optionally a file in the destination tree) and dst points
137 * at a newly created file. They may be quite similar, in which
138 * case we want to say src is renamed to dst or src is copied into
139 * dst, and then some edit has been applied to dst.
140 *
141 * Compare them and return how similar they are, representing
f0c6b2a2
JH
142 * the score as an integer between 0 and MAX_SCORE.
143 *
144 * When there is an exact match, it is considered a better
145 * match than anything else; the destination does not even
146 * call into this function in that case.
427dcb4b 147 */
90bd932c 148 unsigned long max_size, delta_size, base_size, src_copied, literal_added;
427dcb4b
JH
149 int score;
150
60896c7b
JH
151 /* We deal only with regular files. Symlink renames are handled
152 * only when they are exact matches --- in other words, no edits
153 * after renaming.
154 */
155 if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
156 return 0;
157
81ac051d
LT
158 /*
159 * Need to check that source and destination sizes are
160 * filled in before comparing them.
161 *
162 * If we already have "cnt_data" filled in, we know it's
163 * all good (avoid checking the size for zero, as that
164 * is a possible size - we really should have a flag to
165 * say whether the size is valid or not!)
166 */
8e5dd3d6
NTND
167 if (!src->cnt_data &&
168 diff_populate_filespec(src, CHECK_SIZE_ONLY))
81ac051d 169 return 0;
8e5dd3d6
NTND
170 if (!dst->cnt_data &&
171 diff_populate_filespec(dst, CHECK_SIZE_ONLY))
81ac051d
LT
172 return 0;
173
90bd932c 174 max_size = ((src->size > dst->size) ? src->size : dst->size);
58b103f5 175 base_size = ((src->size < dst->size) ? src->size : dst->size);
90bd932c 176 delta_size = max_size - base_size;
427dcb4b 177
58b103f5
JH
178 /* We would not consider edits that change the file size so
179 * drastically. delta_size must be smaller than
cd1870ed 180 * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
f0c6b2a2 181 *
58b103f5
JH
182 * Note that base_size == 0 case is handled here already
183 * and the final score computation below would not have a
184 * divide-by-zero issue.
427dcb4b 185 */
3a4d6769 186 if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
427dcb4b
JH
187 return 0;
188
885c716f
BS
189 if (!src->cnt_data && diff_populate_filespec(src, 0))
190 return 0;
191 if (!dst->cnt_data && diff_populate_filespec(dst, 0))
192 return 0;
193
d8c3d03a 194 if (diffcore_count_changes(src, dst,
c06c7966 195 &src->cnt_data, &dst->cnt_data,
65416758 196 &src_copied, &literal_added))
85976974 197 return 0;
355e76a4 198
1706306a
JH
199 /* How similar are they?
200 * what percentage of material in dst are from source?
427dcb4b 201 */
90bd932c 202 if (!dst->size)
1706306a 203 score = 0; /* should not happen */
cfc0aef1 204 else
dc49cd76 205 score = (int)(src_copied * MAX_SCORE / max_size);
427dcb4b
JH
206 return score;
207}
208
5098bafb 209static void record_rename_pair(int dst_index, int src_index, int score)
427dcb4b 210{
9fb88419 211 struct diff_filespec *src, *dst;
25d5ea41 212 struct diff_filepair *dp;
f7c1512a 213
25d5ea41
JH
214 if (rename_dst[dst_index].pair)
215 die("internal error: dst already matched.");
427dcb4b 216
e88d6bc6 217 src = rename_src[src_index].p->one;
64479711 218 src->rename_used++;
9fb88419 219 src->count++;
427dcb4b 220
25d5ea41 221 dst = rename_dst[dst_index].two;
9fb88419 222 dst->count++;
427dcb4b 223
9fb88419 224 dp = diff_queue(NULL, src, dst);
ef677686 225 dp->renamed_pair = 1;
fc580719
JH
226 if (!strcmp(src->path, dst->path))
227 dp->score = rename_src[src_index].score;
228 else
229 dp->score = score;
25d5ea41 230 rename_dst[dst_index].pair = dp;
427dcb4b
JH
231}
232
233/*
234 * We sort the rename similarity matrix with the score, in descending
15d061b4 235 * order (the most similar first).
427dcb4b
JH
236 */
237static int score_compare(const void *a_, const void *b_)
238{
239 const struct diff_score *a = a_, *b = b_;
cfc0aef1 240
6d24ad97
JH
241 /* sink the unused ones to the bottom */
242 if (a->dst < 0)
243 return (0 <= b->dst);
244 else if (b->dst < 0)
245 return -1;
246
cfc0aef1
RS
247 if (a->score == b->score)
248 return b->name_score - a->name_score;
249
427dcb4b
JH
250 return b->score - a->score;
251}
252
9027f53c 253struct file_similarity {
f79d9c58 254 struct hashmap_entry entry;
7c85f8ac 255 int index;
9027f53c 256 struct diff_filespec *filespec;
9027f53c
LT
257};
258
48f6407f
KB
259static unsigned int hash_filespec(struct diff_filespec *filespec)
260{
41c9560e 261 if (!filespec->oid_valid) {
48f6407f
KB
262 if (diff_populate_filespec(filespec, 0))
263 return 0;
f070facc
PO
264 hash_object_file(filespec->data, filespec->size, "blob",
265 &filespec->oid);
48f6407f 266 }
a0d12c44 267 return sha1hash(filespec->oid.hash);
48f6407f
KB
268}
269
f79d9c58 270static int find_identical_files(struct hashmap *srcs,
7c85f8ac 271 int dst_index,
11f944dd 272 struct diff_options *options)
9027f53c
LT
273{
274 int renames = 0;
275
7c85f8ac 276 struct diff_filespec *target = rename_dst[dst_index].two;
ab73a9d1 277 struct file_similarity *p, *best = NULL;
48f6407f
KB
278 int i = 100, best_score = -1;
279
280 /*
7c85f8ac 281 * Find the best source match for specified destination.
48f6407f 282 */
ab73a9d1
KB
283 p = hashmap_get_from_hash(srcs, hash_filespec(target), NULL);
284 for (; p; p = hashmap_get_next(srcs, p)) {
48f6407f
KB
285 int score;
286 struct diff_filespec *source = p->filespec;
287
288 /* False hash collision? */
a0d12c44 289 if (oidcmp(&source->oid, &target->oid))
48f6407f
KB
290 continue;
291 /* Non-regular files? If so, the modes must match! */
292 if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
293 if (source->mode != target->mode)
0940e5f2 294 continue;
9027f53c 295 }
48f6407f
KB
296 /* Give higher scores to sources that haven't been used already */
297 score = !source->rename_used;
298 if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
299 continue;
300 score += basename_same(source, target);
301 if (score > best_score) {
302 best = p;
303 best_score = score;
304 if (score == 2)
305 break;
9027f53c 306 }
48f6407f
KB
307
308 /* Too many identical alternatives? Pick one */
309 if (!--i)
310 break;
311 }
312 if (best) {
7c85f8ac 313 record_rename_pair(dst_index, best->index, MAX_SCORE);
48f6407f
KB
314 renames++;
315 }
9027f53c
LT
316 return renames;
317}
318
f79d9c58 319static void insert_file_table(struct hashmap *table, int index, struct diff_filespec *filespec)
9027f53c 320{
9027f53c
LT
321 struct file_similarity *entry = xmalloc(sizeof(*entry));
322
9027f53c
LT
323 entry->index = index;
324 entry->filespec = filespec;
9027f53c 325
f79d9c58
KB
326 hashmap_entry_init(entry, hash_filespec(filespec));
327 hashmap_add(table, entry);
9027f53c
LT
328}
329
cb1491b6
LT
330/*
331 * Find exact renames first.
332 *
333 * The first round matches up the up-to-date entries,
334 * and then during the second round we try to match
335 * cache-dirty entries as well.
cb1491b6 336 */
11f944dd 337static int find_exact_renames(struct diff_options *options)
cb1491b6 338{
7c85f8ac 339 int i, renames = 0;
f79d9c58 340 struct hashmap file_table;
cb1491b6 341
ca4e3ca0
SG
342 /* Add all sources to the hash table in reverse order, because
343 * later on they will be retrieved in LIFO order.
344 */
7663cdc8 345 hashmap_init(&file_table, NULL, NULL, rename_src_nr);
ca4e3ca0 346 for (i = rename_src_nr-1; i >= 0; i--)
7c85f8ac 347 insert_file_table(&file_table, i, rename_src[i].p->one);
9027f53c 348
7c85f8ac 349 /* Walk the destinations and find best source match */
9027f53c 350 for (i = 0; i < rename_dst_nr; i++)
7c85f8ac 351 renames += find_identical_files(&file_table, i, options);
9027f53c 352
f79d9c58
KB
353 /* Free the hash data structure and entries */
354 hashmap_free(&file_table, 1);
9027f53c 355
7c85f8ac 356 return renames;
cb1491b6
LT
357}
358
6d24ad97
JH
359#define NUM_CANDIDATE_PER_DST 4
360static void record_if_better(struct diff_score m[], struct diff_score *o)
361{
362 int i, worst;
363
364 /* find the worst one */
365 worst = 0;
366 for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
367 if (score_compare(&m[i], &m[worst]) > 0)
368 worst = i;
369
370 /* is it better than the worst one? */
371 if (score_compare(&m[worst], o) > 0)
372 m[worst] = *o;
373}
374
f31027c9
JH
375/*
376 * Returns:
377 * 0 if we are under the limit;
378 * 1 if we need to disable inexact rename detection;
379 * 2 if we would be under the limit if we were given -C instead of -C -C.
380 */
9d8a5a50
JH
381static int too_many_rename_candidates(int num_create,
382 struct diff_options *options)
383{
384 int rename_limit = options->rename_limit;
385 int num_src = rename_src_nr;
f31027c9 386 int i;
9d8a5a50
JH
387
388 options->needed_rename_limit = 0;
389
390 /*
391 * This basically does a test for the rename matrix not
392 * growing larger than a "rename_limit" square matrix, ie:
393 *
394 * num_create * num_src > rename_limit * rename_limit
9d8a5a50 395 */
89973554
JT
396 if (rename_limit <= 0)
397 rename_limit = 32767;
9d8a5a50 398 if ((num_create <= rename_limit || num_src <= rename_limit) &&
9f7e4bfa
EN
399 ((uint64_t)num_create * (uint64_t)num_src
400 <= (uint64_t)rename_limit * (uint64_t)rename_limit))
9d8a5a50
JH
401 return 0;
402
403 options->needed_rename_limit =
404 num_src > num_create ? num_src : num_create;
f31027c9
JH
405
406 /* Are we running under -C -C? */
0d1e0e78 407 if (!options->flags.find_copies_harder)
f31027c9
JH
408 return 1;
409
410 /* Would we bust the limit if we were running under -C? */
411 for (num_src = i = 0; i < rename_src_nr; i++) {
412 if (diff_unmodified_pair(rename_src[i].p))
413 continue;
414 num_src++;
415 }
416 if ((num_create <= rename_limit || num_src <= rename_limit) &&
9f7e4bfa
EN
417 ((uint64_t)num_create * (uint64_t)num_src
418 <= (uint64_t)rename_limit * (uint64_t)rename_limit))
f31027c9 419 return 2;
9d8a5a50
JH
420 return 1;
421}
422
0940e5f2
LT
423static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
424{
425 int count = 0, i;
426
427 for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
428 struct diff_rename_dst *dst;
429
430 if ((mx[i].dst < 0) ||
431 (mx[i].score < minimum_score))
432 break; /* there is no more usable pair. */
433 dst = &rename_dst[mx[i].dst];
434 if (dst->pair)
435 continue; /* already done, either exact or fuzzy. */
e88d6bc6 436 if (!copies && rename_src[mx[i].src].p->one->rename_used)
0940e5f2
LT
437 continue;
438 record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
439 count++;
440 }
441 return count;
442}
443
8082d8d3 444void diffcore_rename(struct diff_options *options)
427dcb4b 445{
8082d8d3
JH
446 int detect_rename = options->detect_rename;
447 int minimum_score = options->rename_score;
38c6f780 448 struct diff_queue_struct *q = &diff_queued_diff;
5098bafb 449 struct diff_queue_struct outq;
427dcb4b 450 struct diff_score *mx;
f31027c9 451 int i, j, rename_count, skip_unmodified = 0;
dabdbee1 452 int num_create, dst_cnt;
3ac942d4 453 struct progress *progress = NULL;
427dcb4b 454
26dee0ad 455 if (!minimum_score)
f345b0a0 456 minimum_score = DEFAULT_RENAME_SCORE;
427dcb4b 457
427dcb4b 458 for (i = 0; i < q->nr; i++) {
52e95789 459 struct diff_filepair *p = q->queue[i];
2f3f8b21 460 if (!DIFF_FILE_VALID(p->one)) {
81e50eab 461 if (!DIFF_FILE_VALID(p->two))
60896c7b 462 continue; /* unmerged */
2f3f8b21
JH
463 else if (options->single_follow &&
464 strcmp(options->single_follow, p->two->path))
465 continue; /* not interested */
0d1e0e78 466 else if (!options->flags.rename_empty &&
02491b67 467 is_empty_blob_oid(&p->two->oid))
90d43b07 468 continue;
4d6be03b
JK
469 else if (add_rename_dst(p->two) < 0) {
470 warning("skipping rename detection, detected"
471 " duplicate destination '%s'",
472 p->two->path);
473 goto cleanup;
474 }
2f3f8b21 475 }
0d1e0e78 476 else if (!options->flags.rename_empty &&
02491b67 477 is_empty_blob_oid(&p->one->oid))
90d43b07 478 continue;
d7c9bf22 479 else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
64479711
LT
480 /*
481 * If the source is a broken "delete", and
2210100a
JH
482 * they did not really want to get broken,
483 * that means the source actually stays.
64479711
LT
484 * So we increment the "rename_used" score
485 * by one, to indicate ourselves as a user
486 */
487 if (p->broken_pair && !p->score)
488 p->one->rename_used++;
e88d6bc6 489 register_rename_src(p);
64479711
LT
490 }
491 else if (detect_rename == DIFF_DETECT_COPY) {
492 /*
493 * Increment the "rename_used" score by
494 * one, to indicate ourselves as a user.
2210100a 495 */
64479711 496 p->one->rename_used++;
e88d6bc6 497 register_rename_src(p);
2210100a 498 }
427dcb4b 499 }
0024a549 500 if (rename_dst_nr == 0 || rename_src_nr == 0)
427dcb4b
JH
501 goto cleanup; /* nothing to do */
502
17559a64
LT
503 /*
504 * We really want to cull the candidates list early
505 * with cheap tests in order to avoid doing deltas.
506 */
11f944dd 507 rename_count = find_exact_renames(options);
17559a64 508
42899ac8
LT
509 /* Did we only want exact renames? */
510 if (minimum_score == MAX_SCORE)
511 goto cleanup;
512
513 /*
514 * Calculate how many renames are left (but all the source
515 * files still remain as options for rename/copies!)
516 */
517 num_create = (rename_dst_nr - rename_count);
42899ac8
LT
518
519 /* All done? */
520 if (!num_create)
521 goto cleanup;
522
f31027c9
JH
523 switch (too_many_rename_candidates(num_create, options)) {
524 case 1:
0024a549 525 goto cleanup;
f31027c9
JH
526 case 2:
527 options->degraded_cc_to_c = 1;
528 skip_unmodified = 1;
529 break;
530 default:
531 break;
532 }
0024a549 533
3ac942d4 534 if (options->show_rename_progress) {
8aade107 535 progress = start_delayed_progress(
754dbc43 536 _("Performing inexact rename detection"),
d6861d02 537 (uint64_t)rename_dst_nr * (uint64_t)rename_src_nr);
3ac942d4
JK
538 }
539
50492f7b 540 mx = xcalloc(st_mult(NUM_CANDIDATE_PER_DST, num_create), sizeof(*mx));
25d5ea41 541 for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
25d5ea41 542 struct diff_filespec *two = rename_dst[i].two;
6d24ad97
JH
543 struct diff_score *m;
544
25d5ea41 545 if (rename_dst[i].pair)
427dcb4b 546 continue; /* dealt with exact match already. */
6d24ad97
JH
547
548 m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
549 for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
550 m[j].dst = -1;
551
25d5ea41 552 for (j = 0; j < rename_src_nr; j++) {
e88d6bc6 553 struct diff_filespec *one = rename_src[j].p->one;
6d24ad97 554 struct diff_score this_src;
f31027c9
JH
555
556 if (skip_unmodified &&
557 diff_unmodified_pair(rename_src[j].p))
558 continue;
559
6d24ad97
JH
560 this_src.score = estimate_similarity(one, two,
561 minimum_score);
562 this_src.name_score = basename_same(one, two);
563 this_src.dst = i;
564 this_src.src = j;
565 record_if_better(m, &this_src);
809809bb
JH
566 /*
567 * Once we run estimate_similarity,
568 * We do not need the text anymore.
569 */
8ae92e63 570 diff_free_filespec_blob(one);
809809bb 571 diff_free_filespec_blob(two);
427dcb4b
JH
572 }
573 dst_cnt++;
d6861d02 574 display_progress(progress, (uint64_t)(i+1)*(uint64_t)rename_src_nr);
427dcb4b 575 }
3ac942d4 576 stop_progress(&progress);
6d24ad97 577
427dcb4b 578 /* cost matrix sorted by most to least similar pair */
9ed0d8d6 579 QSORT(mx, dst_cnt * NUM_CANDIDATE_PER_DST, score_compare);
6d24ad97 580
0940e5f2
LT
581 rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
582 if (detect_rename == DIFF_DETECT_COPY)
583 rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
427dcb4b 584 free(mx);
427dcb4b 585
15d061b4 586 cleanup:
427dcb4b 587 /* At this point, we have found some renames and copies and they
5098bafb 588 * are recorded in rename_dst. The original list is still in *q.
427dcb4b 589 */
9ca5df90 590 DIFF_QUEUE_CLEAR(&outq);
427dcb4b 591 for (i = 0; i < q->nr; i++) {
25d5ea41 592 struct diff_filepair *p = q->queue[i];
25d5ea41
JH
593 struct diff_filepair *pair_to_free = NULL;
594
d7c9bf22
MZ
595 if (DIFF_PAIR_UNMERGED(p)) {
596 diff_q(&outq, p);
597 }
598 else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2cd68882
JH
599 /*
600 * Creation
601 *
602 * We would output this create record if it has
603 * not been turned into a rename/copy already.
604 */
f98c2f7e 605 struct diff_rename_dst *dst = locate_rename_dst(p->two);
2cd68882 606 if (dst && dst->pair) {
25d5ea41
JH
607 diff_q(&outq, dst->pair);
608 pair_to_free = p;
609 }
610 else
2cd68882
JH
611 /* no matching rename/copy source, so
612 * record this as a creation.
25d5ea41
JH
613 */
614 diff_q(&outq, p);
427dcb4b 615 }
2cd68882
JH
616 else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) {
617 /*
618 * Deletion
619 *
f345b0a0
JH
620 * We would output this delete record if:
621 *
622 * (1) this is a broken delete and the counterpart
623 * broken create remains in the output; or
5098bafb
JH
624 * (2) this is not a broken delete, and rename_dst
625 * does not have a rename/copy to move p->one->path
626 * out of existence.
f345b0a0
JH
627 *
628 * Otherwise, the counterpart broken create
629 * has been turned into a rename-edit; or
630 * delete did not have a matching create to
631 * begin with.
2cd68882 632 */
f345b0a0
JH
633 if (DIFF_PAIR_BROKEN(p)) {
634 /* broken delete */
f98c2f7e 635 struct diff_rename_dst *dst = locate_rename_dst(p->one);
f345b0a0
JH
636 if (dst && dst->pair)
637 /* counterpart is now rename/copy */
638 pair_to_free = p;
639 }
640 else {
64479711 641 if (p->one->rename_used)
f345b0a0
JH
642 /* this path remains */
643 pair_to_free = p;
644 }
2cd68882
JH
645
646 if (pair_to_free)
647 ;
648 else
649 diff_q(&outq, p);
650 }
25d5ea41 651 else if (!diff_unmodified_pair(p))
15d061b4 652 /* all the usual ones need to be kept */
25d5ea41 653 diff_q(&outq, p);
15d061b4
JH
654 else
655 /* no need to keep unmodified pairs */
656 pair_to_free = p;
657
226406f6
JH
658 if (pair_to_free)
659 diff_free_filepair(pair_to_free);
427dcb4b 660 }
25d5ea41 661 diff_debug_queue("done copying original", &outq);
427dcb4b 662
25d5ea41
JH
663 free(q->queue);
664 *q = outq;
665 diff_debug_queue("done collapsing", q);
427dcb4b 666
9fb88419
LT
667 for (i = 0; i < rename_dst_nr; i++)
668 free_filespec(rename_dst[i].two);
5098bafb 669
6a83d902 670 FREE_AND_NULL(rename_dst);
25d5ea41 671 rename_dst_nr = rename_dst_alloc = 0;
6a83d902 672 FREE_AND_NULL(rename_src);
25d5ea41 673 rename_src_nr = rename_src_alloc = 0;
427dcb4b
JH
674 return;
675}