diffcore-rename.c: simplify finding exact renames
[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"
9027f53c 7#include "hash.h"
3ac942d4 8#include "progress.h"
427dcb4b 9
25d5ea41
JH
10/* Table of rename/copy destinations */
11
12static struct diff_rename_dst {
13 struct diff_filespec *two;
14 struct diff_filepair *pair;
15} *rename_dst;
16static int rename_dst_nr, rename_dst_alloc;
427dcb4b 17
25d5ea41
JH
18static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
19 int insert_ok)
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)
30 return dst;
31 if (cmp < 0) {
32 last = next;
33 continue;
34 }
35 first = next+1;
36 }
37 /* not found */
38 if (!insert_ok)
39 return NULL;
40 /* insert to make it at "first" */
41 if (rename_dst_alloc <= rename_dst_nr) {
42 rename_dst_alloc = alloc_nr(rename_dst_alloc);
43 rename_dst = xrealloc(rename_dst,
44 rename_dst_alloc * sizeof(*rename_dst));
45 }
46 rename_dst_nr++;
47 if (first < rename_dst_nr)
48 memmove(rename_dst + first + 1, rename_dst + first,
49 (rename_dst_nr - first - 1) * sizeof(*rename_dst));
5098bafb 50 rename_dst[first].two = alloc_filespec(two->path);
e5450100 51 fill_filespec(rename_dst[first].two, two->sha1, two->sha1_valid, two->mode);
25d5ea41
JH
52 rename_dst[first].pair = NULL;
53 return &(rename_dst[first]);
427dcb4b
JH
54}
55
15d061b4 56/* Table of rename/copy src files */
25d5ea41 57static struct diff_rename_src {
e88d6bc6 58 struct diff_filepair *p;
fc580719 59 unsigned short score; /* to remember the break score */
25d5ea41
JH
60} *rename_src;
61static int rename_src_nr, rename_src_alloc;
427dcb4b 62
e88d6bc6 63static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
25d5ea41
JH
64{
65 int first, last;
e88d6bc6
JH
66 struct diff_filespec *one = p->one;
67 unsigned short score = p->score;
25d5ea41
JH
68
69 first = 0;
70 last = rename_src_nr;
71 while (last > first) {
72 int next = (last + first) >> 1;
73 struct diff_rename_src *src = &(rename_src[next]);
e88d6bc6 74 int cmp = strcmp(one->path, src->p->one->path);
25d5ea41
JH
75 if (!cmp)
76 return src;
77 if (cmp < 0) {
78 last = next;
79 continue;
80 }
81 first = next+1;
82 }
15d061b4 83
25d5ea41
JH
84 /* insert to make it at "first" */
85 if (rename_src_alloc <= rename_src_nr) {
86 rename_src_alloc = alloc_nr(rename_src_alloc);
87 rename_src = xrealloc(rename_src,
88 rename_src_alloc * sizeof(*rename_src));
427dcb4b 89 }
25d5ea41
JH
90 rename_src_nr++;
91 if (first < rename_src_nr)
92 memmove(rename_src + first + 1, rename_src + first,
93 (rename_src_nr - first - 1) * sizeof(*rename_src));
e88d6bc6 94 rename_src[first].p = p;
fc580719 95 rename_src[first].score = score;
25d5ea41 96 return &(rename_src[first]);
427dcb4b
JH
97}
98
0ce39643
JS
99static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
100{
101 int src_len = strlen(src->path), dst_len = strlen(dst->path);
102 while (src_len && dst_len) {
103 char c1 = src->path[--src_len];
104 char c2 = dst->path[--dst_len];
105 if (c1 != c2)
106 return 0;
107 if (c1 == '/')
108 return 1;
109 }
110 return (!src_len || src->path[src_len - 1] == '/') &&
111 (!dst_len || dst->path[dst_len - 1] == '/');
112}
113
427dcb4b 114struct diff_score {
25d5ea41
JH
115 int src; /* index in rename_src */
116 int dst; /* index in rename_dst */
6d24ad97
JH
117 unsigned short score;
118 short name_score;
427dcb4b
JH
119};
120
121static int estimate_similarity(struct diff_filespec *src,
122 struct diff_filespec *dst,
123 int minimum_score)
124{
125 /* src points at a file that existed in the original tree (or
126 * optionally a file in the destination tree) and dst points
127 * at a newly created file. They may be quite similar, in which
128 * case we want to say src is renamed to dst or src is copied into
129 * dst, and then some edit has been applied to dst.
130 *
131 * Compare them and return how similar they are, representing
f0c6b2a2
JH
132 * the score as an integer between 0 and MAX_SCORE.
133 *
134 * When there is an exact match, it is considered a better
135 * match than anything else; the destination does not even
136 * call into this function in that case.
427dcb4b 137 */
90bd932c 138 unsigned long max_size, delta_size, base_size, src_copied, literal_added;
75c660ac 139 unsigned long delta_limit;
427dcb4b
JH
140 int score;
141
60896c7b
JH
142 /* We deal only with regular files. Symlink renames are handled
143 * only when they are exact matches --- in other words, no edits
144 * after renaming.
145 */
146 if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
147 return 0;
148
81ac051d
LT
149 /*
150 * Need to check that source and destination sizes are
151 * filled in before comparing them.
152 *
153 * If we already have "cnt_data" filled in, we know it's
154 * all good (avoid checking the size for zero, as that
155 * is a possible size - we really should have a flag to
156 * say whether the size is valid or not!)
157 */
885c716f 158 if (!src->cnt_data && diff_populate_filespec(src, 1))
81ac051d 159 return 0;
885c716f 160 if (!dst->cnt_data && diff_populate_filespec(dst, 1))
81ac051d
LT
161 return 0;
162
90bd932c 163 max_size = ((src->size > dst->size) ? src->size : dst->size);
58b103f5 164 base_size = ((src->size < dst->size) ? src->size : dst->size);
90bd932c 165 delta_size = max_size - base_size;
427dcb4b 166
58b103f5
JH
167 /* We would not consider edits that change the file size so
168 * drastically. delta_size must be smaller than
cd1870ed 169 * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
f0c6b2a2 170 *
58b103f5
JH
171 * Note that base_size == 0 case is handled here already
172 * and the final score computation below would not have a
173 * divide-by-zero issue.
427dcb4b 174 */
3a4d6769 175 if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
427dcb4b
JH
176 return 0;
177
885c716f
BS
178 if (!src->cnt_data && diff_populate_filespec(src, 0))
179 return 0;
180 if (!dst->cnt_data && diff_populate_filespec(dst, 0))
181 return 0;
182
dc49cd76
SP
183 delta_limit = (unsigned long)
184 (base_size * (MAX_SCORE-minimum_score) / MAX_SCORE);
d8c3d03a 185 if (diffcore_count_changes(src, dst,
c06c7966 186 &src->cnt_data, &dst->cnt_data,
65416758
JH
187 delta_limit,
188 &src_copied, &literal_added))
85976974 189 return 0;
355e76a4 190
1706306a
JH
191 /* How similar are they?
192 * what percentage of material in dst are from source?
427dcb4b 193 */
90bd932c 194 if (!dst->size)
1706306a 195 score = 0; /* should not happen */
cfc0aef1 196 else
dc49cd76 197 score = (int)(src_copied * MAX_SCORE / max_size);
427dcb4b
JH
198 return score;
199}
200
5098bafb 201static void record_rename_pair(int dst_index, int src_index, int score)
427dcb4b 202{
9fb88419 203 struct diff_filespec *src, *dst;
25d5ea41 204 struct diff_filepair *dp;
f7c1512a 205
25d5ea41
JH
206 if (rename_dst[dst_index].pair)
207 die("internal error: dst already matched.");
427dcb4b 208
e88d6bc6 209 src = rename_src[src_index].p->one;
64479711 210 src->rename_used++;
9fb88419 211 src->count++;
427dcb4b 212
25d5ea41 213 dst = rename_dst[dst_index].two;
9fb88419 214 dst->count++;
427dcb4b 215
9fb88419 216 dp = diff_queue(NULL, src, dst);
ef677686 217 dp->renamed_pair = 1;
fc580719
JH
218 if (!strcmp(src->path, dst->path))
219 dp->score = rename_src[src_index].score;
220 else
221 dp->score = score;
25d5ea41 222 rename_dst[dst_index].pair = dp;
427dcb4b
JH
223}
224
225/*
226 * We sort the rename similarity matrix with the score, in descending
15d061b4 227 * order (the most similar first).
427dcb4b
JH
228 */
229static int score_compare(const void *a_, const void *b_)
230{
231 const struct diff_score *a = a_, *b = b_;
cfc0aef1 232
6d24ad97
JH
233 /* sink the unused ones to the bottom */
234 if (a->dst < 0)
235 return (0 <= b->dst);
236 else if (b->dst < 0)
237 return -1;
238
cfc0aef1
RS
239 if (a->score == b->score)
240 return b->name_score - a->name_score;
241
427dcb4b
JH
242 return b->score - a->score;
243}
244
9027f53c 245struct file_similarity {
7c85f8ac 246 int index;
9027f53c
LT
247 struct diff_filespec *filespec;
248 struct file_similarity *next;
249};
250
48f6407f
KB
251static unsigned int hash_filespec(struct diff_filespec *filespec)
252{
253 unsigned int hash;
254 if (!filespec->sha1_valid) {
255 if (diff_populate_filespec(filespec, 0))
256 return 0;
257 hash_sha1_file(filespec->data, filespec->size, "blob", filespec->sha1);
258 }
259 memcpy(&hash, filespec->sha1, sizeof(hash));
260 return hash;
261}
262
7c85f8ac
KB
263static int find_identical_files(struct hash_table *srcs,
264 int dst_index,
11f944dd 265 struct diff_options *options)
9027f53c
LT
266{
267 int renames = 0;
268
7c85f8ac 269 struct diff_filespec *target = rename_dst[dst_index].two;
48f6407f
KB
270 struct file_similarity *p, *best;
271 int i = 100, best_score = -1;
272
273 /*
7c85f8ac 274 * Find the best source match for specified destination.
48f6407f
KB
275 */
276 best = NULL;
7c85f8ac 277 for (p = lookup_hash(hash_filespec(target), srcs); p; p = p->next) {
48f6407f
KB
278 int score;
279 struct diff_filespec *source = p->filespec;
280
281 /* False hash collision? */
282 if (hashcmp(source->sha1, target->sha1))
283 continue;
284 /* Non-regular files? If so, the modes must match! */
285 if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
286 if (source->mode != target->mode)
0940e5f2 287 continue;
9027f53c 288 }
48f6407f
KB
289 /* Give higher scores to sources that haven't been used already */
290 score = !source->rename_used;
291 if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
292 continue;
293 score += basename_same(source, target);
294 if (score > best_score) {
295 best = p;
296 best_score = score;
297 if (score == 2)
298 break;
9027f53c 299 }
48f6407f
KB
300
301 /* Too many identical alternatives? Pick one */
302 if (!--i)
303 break;
304 }
305 if (best) {
7c85f8ac 306 record_rename_pair(dst_index, best->index, MAX_SCORE);
48f6407f
KB
307 renames++;
308 }
9027f53c
LT
309 return renames;
310}
311
7c85f8ac 312static int free_similarity_list(void *p, void *unused)
9027f53c
LT
313{
314 while (p) {
315 struct file_similarity *entry = p;
7c85f8ac 316 p = entry->next;
9027f53c
LT
317 free(entry);
318 }
7c85f8ac 319 return 0;
9027f53c
LT
320}
321
7c85f8ac 322static void insert_file_table(struct hash_table *table, int index, struct diff_filespec *filespec)
9027f53c
LT
323{
324 void **pos;
325 unsigned int hash;
326 struct file_similarity *entry = xmalloc(sizeof(*entry));
327
9027f53c
LT
328 entry->index = index;
329 entry->filespec = filespec;
330 entry->next = NULL;
331
332 hash = hash_filespec(filespec);
333 pos = insert_hash(hash, entry, table);
334
335 /* We already had an entry there? */
336 if (pos) {
337 entry->next = *pos;
338 *pos = entry;
339 }
340}
341
cb1491b6
LT
342/*
343 * Find exact renames first.
344 *
345 * The first round matches up the up-to-date entries,
346 * and then during the second round we try to match
347 * cache-dirty entries as well.
cb1491b6 348 */
11f944dd 349static int find_exact_renames(struct diff_options *options)
cb1491b6 350{
7c85f8ac 351 int i, renames = 0;
9027f53c 352 struct hash_table file_table;
cb1491b6 353
7c85f8ac 354 /* Add all sources to the hash table */
9027f53c 355 init_hash(&file_table);
7c85f8ac 356 preallocate_hash(&file_table, rename_src_nr);
9027f53c 357 for (i = 0; i < rename_src_nr; i++)
7c85f8ac 358 insert_file_table(&file_table, i, rename_src[i].p->one);
9027f53c 359
7c85f8ac 360 /* Walk the destinations and find best source match */
9027f53c 361 for (i = 0; i < rename_dst_nr; i++)
7c85f8ac 362 renames += find_identical_files(&file_table, i, options);
9027f53c 363
7c85f8ac
KB
364 /* Free source file_similarity chains */
365 for_each_hash(&file_table, free_similarity_list, options);
9027f53c
LT
366
367 /* .. and free the hash data structure */
368 free_hash(&file_table);
369
7c85f8ac 370 return renames;
cb1491b6
LT
371}
372
6d24ad97
JH
373#define NUM_CANDIDATE_PER_DST 4
374static void record_if_better(struct diff_score m[], struct diff_score *o)
375{
376 int i, worst;
377
378 /* find the worst one */
379 worst = 0;
380 for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
381 if (score_compare(&m[i], &m[worst]) > 0)
382 worst = i;
383
384 /* is it better than the worst one? */
385 if (score_compare(&m[worst], o) > 0)
386 m[worst] = *o;
387}
388
f31027c9
JH
389/*
390 * Returns:
391 * 0 if we are under the limit;
392 * 1 if we need to disable inexact rename detection;
393 * 2 if we would be under the limit if we were given -C instead of -C -C.
394 */
9d8a5a50
JH
395static int too_many_rename_candidates(int num_create,
396 struct diff_options *options)
397{
398 int rename_limit = options->rename_limit;
399 int num_src = rename_src_nr;
f31027c9 400 int i;
9d8a5a50
JH
401
402 options->needed_rename_limit = 0;
403
404 /*
405 * This basically does a test for the rename matrix not
406 * growing larger than a "rename_limit" square matrix, ie:
407 *
408 * num_create * num_src > rename_limit * rename_limit
409 *
410 * but handles the potential overflow case specially (and we
411 * assume at least 32-bit integers)
412 */
413 if (rename_limit <= 0 || rename_limit > 32767)
414 rename_limit = 32767;
415 if ((num_create <= rename_limit || num_src <= rename_limit) &&
416 (num_create * num_src <= rename_limit * rename_limit))
417 return 0;
418
419 options->needed_rename_limit =
420 num_src > num_create ? num_src : num_create;
f31027c9
JH
421
422 /* Are we running under -C -C? */
423 if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER))
424 return 1;
425
426 /* Would we bust the limit if we were running under -C? */
427 for (num_src = i = 0; i < rename_src_nr; i++) {
428 if (diff_unmodified_pair(rename_src[i].p))
429 continue;
430 num_src++;
431 }
432 if ((num_create <= rename_limit || num_src <= rename_limit) &&
433 (num_create * num_src <= rename_limit * rename_limit))
434 return 2;
9d8a5a50
JH
435 return 1;
436}
437
0940e5f2
LT
438static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
439{
440 int count = 0, i;
441
442 for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
443 struct diff_rename_dst *dst;
444
445 if ((mx[i].dst < 0) ||
446 (mx[i].score < minimum_score))
447 break; /* there is no more usable pair. */
448 dst = &rename_dst[mx[i].dst];
449 if (dst->pair)
450 continue; /* already done, either exact or fuzzy. */
e88d6bc6 451 if (!copies && rename_src[mx[i].src].p->one->rename_used)
0940e5f2
LT
452 continue;
453 record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
454 count++;
455 }
456 return count;
457}
458
8082d8d3 459void diffcore_rename(struct diff_options *options)
427dcb4b 460{
8082d8d3
JH
461 int detect_rename = options->detect_rename;
462 int minimum_score = options->rename_score;
38c6f780 463 struct diff_queue_struct *q = &diff_queued_diff;
5098bafb 464 struct diff_queue_struct outq;
427dcb4b 465 struct diff_score *mx;
f31027c9 466 int i, j, rename_count, skip_unmodified = 0;
dabdbee1 467 int num_create, dst_cnt;
3ac942d4 468 struct progress *progress = NULL;
427dcb4b 469
26dee0ad 470 if (!minimum_score)
f345b0a0 471 minimum_score = DEFAULT_RENAME_SCORE;
427dcb4b 472
427dcb4b 473 for (i = 0; i < q->nr; i++) {
52e95789 474 struct diff_filepair *p = q->queue[i];
2f3f8b21 475 if (!DIFF_FILE_VALID(p->one)) {
81e50eab 476 if (!DIFF_FILE_VALID(p->two))
60896c7b 477 continue; /* unmerged */
2f3f8b21
JH
478 else if (options->single_follow &&
479 strcmp(options->single_follow, p->two->path))
480 continue; /* not interested */
90d43b07
JK
481 else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
482 is_empty_blob_sha1(p->two->sha1))
483 continue;
427dcb4b 484 else
25d5ea41 485 locate_rename_dst(p->two, 1);
2f3f8b21 486 }
90d43b07
JK
487 else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
488 is_empty_blob_sha1(p->one->sha1))
489 continue;
d7c9bf22 490 else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
64479711
LT
491 /*
492 * If the source is a broken "delete", and
2210100a
JH
493 * they did not really want to get broken,
494 * that means the source actually stays.
64479711
LT
495 * So we increment the "rename_used" score
496 * by one, to indicate ourselves as a user
497 */
498 if (p->broken_pair && !p->score)
499 p->one->rename_used++;
e88d6bc6 500 register_rename_src(p);
64479711
LT
501 }
502 else if (detect_rename == DIFF_DETECT_COPY) {
503 /*
504 * Increment the "rename_used" score by
505 * one, to indicate ourselves as a user.
2210100a 506 */
64479711 507 p->one->rename_used++;
e88d6bc6 508 register_rename_src(p);
2210100a 509 }
427dcb4b 510 }
0024a549 511 if (rename_dst_nr == 0 || rename_src_nr == 0)
427dcb4b
JH
512 goto cleanup; /* nothing to do */
513
17559a64
LT
514 /*
515 * We really want to cull the candidates list early
516 * with cheap tests in order to avoid doing deltas.
517 */
11f944dd 518 rename_count = find_exact_renames(options);
17559a64 519
42899ac8
LT
520 /* Did we only want exact renames? */
521 if (minimum_score == MAX_SCORE)
522 goto cleanup;
523
524 /*
525 * Calculate how many renames are left (but all the source
526 * files still remain as options for rename/copies!)
527 */
528 num_create = (rename_dst_nr - rename_count);
42899ac8
LT
529
530 /* All done? */
531 if (!num_create)
532 goto cleanup;
533
f31027c9
JH
534 switch (too_many_rename_candidates(num_create, options)) {
535 case 1:
0024a549 536 goto cleanup;
f31027c9
JH
537 case 2:
538 options->degraded_cc_to_c = 1;
539 skip_unmodified = 1;
540 break;
541 default:
542 break;
543 }
0024a549 544
3ac942d4
JK
545 if (options->show_rename_progress) {
546 progress = start_progress_delay(
547 "Performing inexact rename detection",
548 rename_dst_nr * rename_src_nr, 50, 1);
549 }
550
6d24ad97 551 mx = xcalloc(num_create * NUM_CANDIDATE_PER_DST, sizeof(*mx));
25d5ea41 552 for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
25d5ea41 553 struct diff_filespec *two = rename_dst[i].two;
6d24ad97
JH
554 struct diff_score *m;
555
25d5ea41 556 if (rename_dst[i].pair)
427dcb4b 557 continue; /* dealt with exact match already. */
6d24ad97
JH
558
559 m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
560 for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
561 m[j].dst = -1;
562
25d5ea41 563 for (j = 0; j < rename_src_nr; j++) {
e88d6bc6 564 struct diff_filespec *one = rename_src[j].p->one;
6d24ad97 565 struct diff_score this_src;
f31027c9
JH
566
567 if (skip_unmodified &&
568 diff_unmodified_pair(rename_src[j].p))
569 continue;
570
6d24ad97
JH
571 this_src.score = estimate_similarity(one, two,
572 minimum_score);
573 this_src.name_score = basename_same(one, two);
574 this_src.dst = i;
575 this_src.src = j;
576 record_if_better(m, &this_src);
809809bb
JH
577 /*
578 * Once we run estimate_similarity,
579 * We do not need the text anymore.
580 */
8ae92e63 581 diff_free_filespec_blob(one);
809809bb 582 diff_free_filespec_blob(two);
427dcb4b
JH
583 }
584 dst_cnt++;
3ac942d4 585 display_progress(progress, (i+1)*rename_src_nr);
427dcb4b 586 }
3ac942d4 587 stop_progress(&progress);
6d24ad97 588
427dcb4b 589 /* cost matrix sorted by most to least similar pair */
6d24ad97
JH
590 qsort(mx, dst_cnt * NUM_CANDIDATE_PER_DST, sizeof(*mx), score_compare);
591
0940e5f2
LT
592 rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
593 if (detect_rename == DIFF_DETECT_COPY)
594 rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
427dcb4b 595 free(mx);
427dcb4b 596
15d061b4 597 cleanup:
427dcb4b 598 /* At this point, we have found some renames and copies and they
5098bafb 599 * are recorded in rename_dst. The original list is still in *q.
427dcb4b 600 */
9ca5df90 601 DIFF_QUEUE_CLEAR(&outq);
427dcb4b 602 for (i = 0; i < q->nr; i++) {
25d5ea41 603 struct diff_filepair *p = q->queue[i];
25d5ea41
JH
604 struct diff_filepair *pair_to_free = NULL;
605
d7c9bf22
MZ
606 if (DIFF_PAIR_UNMERGED(p)) {
607 diff_q(&outq, p);
608 }
609 else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2cd68882
JH
610 /*
611 * Creation
612 *
613 * We would output this create record if it has
614 * not been turned into a rename/copy already.
615 */
616 struct diff_rename_dst *dst =
617 locate_rename_dst(p->two, 0);
618 if (dst && dst->pair) {
25d5ea41
JH
619 diff_q(&outq, dst->pair);
620 pair_to_free = p;
621 }
622 else
2cd68882
JH
623 /* no matching rename/copy source, so
624 * record this as a creation.
25d5ea41
JH
625 */
626 diff_q(&outq, p);
427dcb4b 627 }
2cd68882
JH
628 else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) {
629 /*
630 * Deletion
631 *
f345b0a0
JH
632 * We would output this delete record if:
633 *
634 * (1) this is a broken delete and the counterpart
635 * broken create remains in the output; or
5098bafb
JH
636 * (2) this is not a broken delete, and rename_dst
637 * does not have a rename/copy to move p->one->path
638 * out of existence.
f345b0a0
JH
639 *
640 * Otherwise, the counterpart broken create
641 * has been turned into a rename-edit; or
642 * delete did not have a matching create to
643 * begin with.
2cd68882 644 */
f345b0a0
JH
645 if (DIFF_PAIR_BROKEN(p)) {
646 /* broken delete */
647 struct diff_rename_dst *dst =
648 locate_rename_dst(p->one, 0);
649 if (dst && dst->pair)
650 /* counterpart is now rename/copy */
651 pair_to_free = p;
652 }
653 else {
64479711 654 if (p->one->rename_used)
f345b0a0
JH
655 /* this path remains */
656 pair_to_free = p;
657 }
2cd68882
JH
658
659 if (pair_to_free)
660 ;
661 else
662 diff_q(&outq, p);
663 }
25d5ea41 664 else if (!diff_unmodified_pair(p))
15d061b4 665 /* all the usual ones need to be kept */
25d5ea41 666 diff_q(&outq, p);
15d061b4
JH
667 else
668 /* no need to keep unmodified pairs */
669 pair_to_free = p;
670
226406f6
JH
671 if (pair_to_free)
672 diff_free_filepair(pair_to_free);
427dcb4b 673 }
25d5ea41 674 diff_debug_queue("done copying original", &outq);
427dcb4b 675
25d5ea41
JH
676 free(q->queue);
677 *q = outq;
678 diff_debug_queue("done collapsing", q);
427dcb4b 679
9fb88419
LT
680 for (i = 0; i < rename_dst_nr; i++)
681 free_filespec(rename_dst[i].two);
5098bafb 682
25d5ea41
JH
683 free(rename_dst);
684 rename_dst = NULL;
685 rename_dst_nr = rename_dst_alloc = 0;
686 free(rename_src);
687 rename_src = NULL;
688 rename_src_nr = rename_src_alloc = 0;
427dcb4b
JH
689 return;
690}