diffcore-rename.con commit Merge branch 'ph/rebase-preserve-all-merges' into maint (da2987d)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "diff.h"
   6#include "diffcore.h"
   7#include "hash.h"
   8#include "progress.h"
   9
  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;
  17
  18static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
  19                                                 int insert_ok)
  20{
  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));
  50        rename_dst[first].two = alloc_filespec(two->path);
  51        fill_filespec(rename_dst[first].two, two->sha1, two->sha1_valid, two->mode);
  52        rename_dst[first].pair = NULL;
  53        return &(rename_dst[first]);
  54}
  55
  56/* Table of rename/copy src files */
  57static struct diff_rename_src {
  58        struct diff_filepair *p;
  59        unsigned short score; /* to remember the break score */
  60} *rename_src;
  61static int rename_src_nr, rename_src_alloc;
  62
  63static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
  64{
  65        int first, last;
  66        struct diff_filespec *one = p->one;
  67        unsigned short score = p->score;
  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]);
  74                int cmp = strcmp(one->path, src->p->one->path);
  75                if (!cmp)
  76                        return src;
  77                if (cmp < 0) {
  78                        last = next;
  79                        continue;
  80                }
  81                first = next+1;
  82        }
  83
  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));
  89        }
  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));
  94        rename_src[first].p = p;
  95        rename_src[first].score = score;
  96        return &(rename_src[first]);
  97}
  98
  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
 114struct diff_score {
 115        int src; /* index in rename_src */
 116        int dst; /* index in rename_dst */
 117        unsigned short score;
 118        short name_score;
 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
 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.
 137         */
 138        unsigned long max_size, delta_size, base_size, src_copied, literal_added;
 139        unsigned long delta_limit;
 140        int score;
 141
 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
 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         */
 158        if (!src->cnt_data && diff_populate_filespec(src, 1))
 159                return 0;
 160        if (!dst->cnt_data && diff_populate_filespec(dst, 1))
 161                return 0;
 162
 163        max_size = ((src->size > dst->size) ? src->size : dst->size);
 164        base_size = ((src->size < dst->size) ? src->size : dst->size);
 165        delta_size = max_size - base_size;
 166
 167        /* We would not consider edits that change the file size so
 168         * drastically.  delta_size must be smaller than
 169         * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
 170         *
 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.
 174         */
 175        if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
 176                return 0;
 177
 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
 183        delta_limit = (unsigned long)
 184                (base_size * (MAX_SCORE-minimum_score) / MAX_SCORE);
 185        if (diffcore_count_changes(src, dst,
 186                                   &src->cnt_data, &dst->cnt_data,
 187                                   delta_limit,
 188                                   &src_copied, &literal_added))
 189                return 0;
 190
 191        /* How similar are they?
 192         * what percentage of material in dst are from source?
 193         */
 194        if (!dst->size)
 195                score = 0; /* should not happen */
 196        else
 197                score = (int)(src_copied * MAX_SCORE / max_size);
 198        return score;
 199}
 200
 201static void record_rename_pair(int dst_index, int src_index, int score)
 202{
 203        struct diff_filespec *src, *dst;
 204        struct diff_filepair *dp;
 205
 206        if (rename_dst[dst_index].pair)
 207                die("internal error: dst already matched.");
 208
 209        src = rename_src[src_index].p->one;
 210        src->rename_used++;
 211        src->count++;
 212
 213        dst = rename_dst[dst_index].two;
 214        dst->count++;
 215
 216        dp = diff_queue(NULL, src, dst);
 217        dp->renamed_pair = 1;
 218        if (!strcmp(src->path, dst->path))
 219                dp->score = rename_src[src_index].score;
 220        else
 221                dp->score = score;
 222        rename_dst[dst_index].pair = dp;
 223}
 224
 225/*
 226 * We sort the rename similarity matrix with the score, in descending
 227 * order (the most similar first).
 228 */
 229static int score_compare(const void *a_, const void *b_)
 230{
 231        const struct diff_score *a = a_, *b = b_;
 232
 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
 239        if (a->score == b->score)
 240                return b->name_score - a->name_score;
 241
 242        return b->score - a->score;
 243}
 244
 245struct file_similarity {
 246        int src_dst, index;
 247        struct diff_filespec *filespec;
 248        struct file_similarity *next;
 249};
 250
 251static int find_identical_files(struct file_similarity *src,
 252                                struct file_similarity *dst,
 253                                struct diff_options *options)
 254{
 255        int renames = 0;
 256
 257        /*
 258         * Walk over all the destinations ...
 259         */
 260        do {
 261                struct diff_filespec *target = dst->filespec;
 262                struct file_similarity *p, *best;
 263                int i = 100, best_score = -1;
 264
 265                /*
 266                 * .. to find the best source match
 267                 */
 268                best = NULL;
 269                for (p = src; p; p = p->next) {
 270                        int score;
 271                        struct diff_filespec *source = p->filespec;
 272
 273                        /* False hash collision? */
 274                        if (hashcmp(source->sha1, target->sha1))
 275                                continue;
 276                        /* Non-regular files? If so, the modes must match! */
 277                        if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
 278                                if (source->mode != target->mode)
 279                                        continue;
 280                        }
 281                        /* Give higher scores to sources that haven't been used already */
 282                        score = !source->rename_used;
 283                        if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
 284                                continue;
 285                        score += basename_same(source, target);
 286                        if (score > best_score) {
 287                                best = p;
 288                                best_score = score;
 289                                if (score == 2)
 290                                        break;
 291                        }
 292
 293                        /* Too many identical alternatives? Pick one */
 294                        if (!--i)
 295                                break;
 296                }
 297                if (best) {
 298                        record_rename_pair(dst->index, best->index, MAX_SCORE);
 299                        renames++;
 300                }
 301        } while ((dst = dst->next) != NULL);
 302        return renames;
 303}
 304
 305static void free_similarity_list(struct file_similarity *p)
 306{
 307        while (p) {
 308                struct file_similarity *entry = p;
 309                p = p->next;
 310                free(entry);
 311        }
 312}
 313
 314static int find_same_files(void *ptr, void *data)
 315{
 316        int ret;
 317        struct file_similarity *p = ptr;
 318        struct file_similarity *src = NULL, *dst = NULL;
 319        struct diff_options *options = data;
 320
 321        /* Split the hash list up into sources and destinations */
 322        do {
 323                struct file_similarity *entry = p;
 324                p = p->next;
 325                if (entry->src_dst < 0) {
 326                        entry->next = src;
 327                        src = entry;
 328                } else {
 329                        entry->next = dst;
 330                        dst = entry;
 331                }
 332        } while (p);
 333
 334        /*
 335         * If we have both sources *and* destinations, see if
 336         * we can match them up
 337         */
 338        ret = (src && dst) ? find_identical_files(src, dst, options) : 0;
 339
 340        /* Free the hashes and return the number of renames found */
 341        free_similarity_list(src);
 342        free_similarity_list(dst);
 343        return ret;
 344}
 345
 346static unsigned int hash_filespec(struct diff_filespec *filespec)
 347{
 348        unsigned int hash;
 349        if (!filespec->sha1_valid) {
 350                if (diff_populate_filespec(filespec, 0))
 351                        return 0;
 352                hash_sha1_file(filespec->data, filespec->size, "blob", filespec->sha1);
 353        }
 354        memcpy(&hash, filespec->sha1, sizeof(hash));
 355        return hash;
 356}
 357
 358static void insert_file_table(struct hash_table *table, int src_dst, int index, struct diff_filespec *filespec)
 359{
 360        void **pos;
 361        unsigned int hash;
 362        struct file_similarity *entry = xmalloc(sizeof(*entry));
 363
 364        entry->src_dst = src_dst;
 365        entry->index = index;
 366        entry->filespec = filespec;
 367        entry->next = NULL;
 368
 369        hash = hash_filespec(filespec);
 370        pos = insert_hash(hash, entry, table);
 371
 372        /* We already had an entry there? */
 373        if (pos) {
 374                entry->next = *pos;
 375                *pos = entry;
 376        }
 377}
 378
 379/*
 380 * Find exact renames first.
 381 *
 382 * The first round matches up the up-to-date entries,
 383 * and then during the second round we try to match
 384 * cache-dirty entries as well.
 385 */
 386static int find_exact_renames(struct diff_options *options)
 387{
 388        int i;
 389        struct hash_table file_table;
 390
 391        init_hash(&file_table);
 392        for (i = 0; i < rename_src_nr; i++)
 393                insert_file_table(&file_table, -1, i, rename_src[i].p->one);
 394
 395        for (i = 0; i < rename_dst_nr; i++)
 396                insert_file_table(&file_table, 1, i, rename_dst[i].two);
 397
 398        /* Find the renames */
 399        i = for_each_hash(&file_table, find_same_files, options);
 400
 401        /* .. and free the hash data structure */
 402        free_hash(&file_table);
 403
 404        return i;
 405}
 406
 407#define NUM_CANDIDATE_PER_DST 4
 408static void record_if_better(struct diff_score m[], struct diff_score *o)
 409{
 410        int i, worst;
 411
 412        /* find the worst one */
 413        worst = 0;
 414        for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
 415                if (score_compare(&m[i], &m[worst]) > 0)
 416                        worst = i;
 417
 418        /* is it better than the worst one? */
 419        if (score_compare(&m[worst], o) > 0)
 420                m[worst] = *o;
 421}
 422
 423/*
 424 * Returns:
 425 * 0 if we are under the limit;
 426 * 1 if we need to disable inexact rename detection;
 427 * 2 if we would be under the limit if we were given -C instead of -C -C.
 428 */
 429static int too_many_rename_candidates(int num_create,
 430                                      struct diff_options *options)
 431{
 432        int rename_limit = options->rename_limit;
 433        int num_src = rename_src_nr;
 434        int i;
 435
 436        options->needed_rename_limit = 0;
 437
 438        /*
 439         * This basically does a test for the rename matrix not
 440         * growing larger than a "rename_limit" square matrix, ie:
 441         *
 442         *    num_create * num_src > rename_limit * rename_limit
 443         *
 444         * but handles the potential overflow case specially (and we
 445         * assume at least 32-bit integers)
 446         */
 447        if (rename_limit <= 0 || rename_limit > 32767)
 448                rename_limit = 32767;
 449        if ((num_create <= rename_limit || num_src <= rename_limit) &&
 450            (num_create * num_src <= rename_limit * rename_limit))
 451                return 0;
 452
 453        options->needed_rename_limit =
 454                num_src > num_create ? num_src : num_create;
 455
 456        /* Are we running under -C -C? */
 457        if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER))
 458                return 1;
 459
 460        /* Would we bust the limit if we were running under -C? */
 461        for (num_src = i = 0; i < rename_src_nr; i++) {
 462                if (diff_unmodified_pair(rename_src[i].p))
 463                        continue;
 464                num_src++;
 465        }
 466        if ((num_create <= rename_limit || num_src <= rename_limit) &&
 467            (num_create * num_src <= rename_limit * rename_limit))
 468                return 2;
 469        return 1;
 470}
 471
 472static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
 473{
 474        int count = 0, i;
 475
 476        for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
 477                struct diff_rename_dst *dst;
 478
 479                if ((mx[i].dst < 0) ||
 480                    (mx[i].score < minimum_score))
 481                        break; /* there is no more usable pair. */
 482                dst = &rename_dst[mx[i].dst];
 483                if (dst->pair)
 484                        continue; /* already done, either exact or fuzzy. */
 485                if (!copies && rename_src[mx[i].src].p->one->rename_used)
 486                        continue;
 487                record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
 488                count++;
 489        }
 490        return count;
 491}
 492
 493void diffcore_rename(struct diff_options *options)
 494{
 495        int detect_rename = options->detect_rename;
 496        int minimum_score = options->rename_score;
 497        struct diff_queue_struct *q = &diff_queued_diff;
 498        struct diff_queue_struct outq;
 499        struct diff_score *mx;
 500        int i, j, rename_count, skip_unmodified = 0;
 501        int num_create, dst_cnt;
 502        struct progress *progress = NULL;
 503
 504        if (!minimum_score)
 505                minimum_score = DEFAULT_RENAME_SCORE;
 506
 507        for (i = 0; i < q->nr; i++) {
 508                struct diff_filepair *p = q->queue[i];
 509                if (!DIFF_FILE_VALID(p->one)) {
 510                        if (!DIFF_FILE_VALID(p->two))
 511                                continue; /* unmerged */
 512                        else if (options->single_follow &&
 513                                 strcmp(options->single_follow, p->two->path))
 514                                continue; /* not interested */
 515                        else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
 516                                 is_empty_blob_sha1(p->two->sha1))
 517                                continue;
 518                        else
 519                                locate_rename_dst(p->two, 1);
 520                }
 521                else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
 522                         is_empty_blob_sha1(p->one->sha1))
 523                        continue;
 524                else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
 525                        /*
 526                         * If the source is a broken "delete", and
 527                         * they did not really want to get broken,
 528                         * that means the source actually stays.
 529                         * So we increment the "rename_used" score
 530                         * by one, to indicate ourselves as a user
 531                         */
 532                        if (p->broken_pair && !p->score)
 533                                p->one->rename_used++;
 534                        register_rename_src(p);
 535                }
 536                else if (detect_rename == DIFF_DETECT_COPY) {
 537                        /*
 538                         * Increment the "rename_used" score by
 539                         * one, to indicate ourselves as a user.
 540                         */
 541                        p->one->rename_used++;
 542                        register_rename_src(p);
 543                }
 544        }
 545        if (rename_dst_nr == 0 || rename_src_nr == 0)
 546                goto cleanup; /* nothing to do */
 547
 548        /*
 549         * We really want to cull the candidates list early
 550         * with cheap tests in order to avoid doing deltas.
 551         */
 552        rename_count = find_exact_renames(options);
 553
 554        /* Did we only want exact renames? */
 555        if (minimum_score == MAX_SCORE)
 556                goto cleanup;
 557
 558        /*
 559         * Calculate how many renames are left (but all the source
 560         * files still remain as options for rename/copies!)
 561         */
 562        num_create = (rename_dst_nr - rename_count);
 563
 564        /* All done? */
 565        if (!num_create)
 566                goto cleanup;
 567
 568        switch (too_many_rename_candidates(num_create, options)) {
 569        case 1:
 570                goto cleanup;
 571        case 2:
 572                options->degraded_cc_to_c = 1;
 573                skip_unmodified = 1;
 574                break;
 575        default:
 576                break;
 577        }
 578
 579        if (options->show_rename_progress) {
 580                progress = start_progress_delay(
 581                                "Performing inexact rename detection",
 582                                rename_dst_nr * rename_src_nr, 50, 1);
 583        }
 584
 585        mx = xcalloc(num_create * NUM_CANDIDATE_PER_DST, sizeof(*mx));
 586        for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
 587                struct diff_filespec *two = rename_dst[i].two;
 588                struct diff_score *m;
 589
 590                if (rename_dst[i].pair)
 591                        continue; /* dealt with exact match already. */
 592
 593                m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
 594                for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
 595                        m[j].dst = -1;
 596
 597                for (j = 0; j < rename_src_nr; j++) {
 598                        struct diff_filespec *one = rename_src[j].p->one;
 599                        struct diff_score this_src;
 600
 601                        if (skip_unmodified &&
 602                            diff_unmodified_pair(rename_src[j].p))
 603                                continue;
 604
 605                        this_src.score = estimate_similarity(one, two,
 606                                                             minimum_score);
 607                        this_src.name_score = basename_same(one, two);
 608                        this_src.dst = i;
 609                        this_src.src = j;
 610                        record_if_better(m, &this_src);
 611                        /*
 612                         * Once we run estimate_similarity,
 613                         * We do not need the text anymore.
 614                         */
 615                        diff_free_filespec_blob(one);
 616                        diff_free_filespec_blob(two);
 617                }
 618                dst_cnt++;
 619                display_progress(progress, (i+1)*rename_src_nr);
 620        }
 621        stop_progress(&progress);
 622
 623        /* cost matrix sorted by most to least similar pair */
 624        qsort(mx, dst_cnt * NUM_CANDIDATE_PER_DST, sizeof(*mx), score_compare);
 625
 626        rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
 627        if (detect_rename == DIFF_DETECT_COPY)
 628                rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
 629        free(mx);
 630
 631 cleanup:
 632        /* At this point, we have found some renames and copies and they
 633         * are recorded in rename_dst.  The original list is still in *q.
 634         */
 635        DIFF_QUEUE_CLEAR(&outq);
 636        for (i = 0; i < q->nr; i++) {
 637                struct diff_filepair *p = q->queue[i];
 638                struct diff_filepair *pair_to_free = NULL;
 639
 640                if (DIFF_PAIR_UNMERGED(p)) {
 641                        diff_q(&outq, p);
 642                }
 643                else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
 644                        /*
 645                         * Creation
 646                         *
 647                         * We would output this create record if it has
 648                         * not been turned into a rename/copy already.
 649                         */
 650                        struct diff_rename_dst *dst =
 651                                locate_rename_dst(p->two, 0);
 652                        if (dst && dst->pair) {
 653                                diff_q(&outq, dst->pair);
 654                                pair_to_free = p;
 655                        }
 656                        else
 657                                /* no matching rename/copy source, so
 658                                 * record this as a creation.
 659                                 */
 660                                diff_q(&outq, p);
 661                }
 662                else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) {
 663                        /*
 664                         * Deletion
 665                         *
 666                         * We would output this delete record if:
 667                         *
 668                         * (1) this is a broken delete and the counterpart
 669                         *     broken create remains in the output; or
 670                         * (2) this is not a broken delete, and rename_dst
 671                         *     does not have a rename/copy to move p->one->path
 672                         *     out of existence.
 673                         *
 674                         * Otherwise, the counterpart broken create
 675                         * has been turned into a rename-edit; or
 676                         * delete did not have a matching create to
 677                         * begin with.
 678                         */
 679                        if (DIFF_PAIR_BROKEN(p)) {
 680                                /* broken delete */
 681                                struct diff_rename_dst *dst =
 682                                        locate_rename_dst(p->one, 0);
 683                                if (dst && dst->pair)
 684                                        /* counterpart is now rename/copy */
 685                                        pair_to_free = p;
 686                        }
 687                        else {
 688                                if (p->one->rename_used)
 689                                        /* this path remains */
 690                                        pair_to_free = p;
 691                        }
 692
 693                        if (pair_to_free)
 694                                ;
 695                        else
 696                                diff_q(&outq, p);
 697                }
 698                else if (!diff_unmodified_pair(p))
 699                        /* all the usual ones need to be kept */
 700                        diff_q(&outq, p);
 701                else
 702                        /* no need to keep unmodified pairs */
 703                        pair_to_free = p;
 704
 705                if (pair_to_free)
 706                        diff_free_filepair(pair_to_free);
 707        }
 708        diff_debug_queue("done copying original", &outq);
 709
 710        free(q->queue);
 711        *q = outq;
 712        diff_debug_queue("done collapsing", q);
 713
 714        for (i = 0; i < rename_dst_nr; i++)
 715                free_filespec(rename_dst[i].two);
 716
 717        free(rename_dst);
 718        rename_dst = NULL;
 719        rename_dst_nr = rename_dst_alloc = 0;
 720        free(rename_src);
 721        rename_src = NULL;
 722        rename_src_nr = rename_src_alloc = 0;
 723        return;
 724}