merge2.c

   1 /*
   2  * wiggle - apply rejected patches
   3  *
   4  * Copyright (C) 2005 Neil Brown <neilb@cse.unsw.edu.au>
   5  * Copyright (C) 2010 Neil Brown <neilb@suse.de>
   6  *
   7  *
   8  *    This program is free software; you can redistribute it and/or modify
   9  *    it under the terms of the GNU General Public License as published by
  10  *    the Free Software Foundation; either version 2 of the License, or
  11  *    (at your option) any later version.
  12  *
  13  *    This program is distributed in the hope that it will be useful,
  14  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *    GNU General Public License for more details.
  17  *
  18  *    You should have received a copy of the GNU General Public License
  19  *    along with this program; if not, write to the Free Software Foundation, Inc.,
  20  *    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  *
  22  *    Author: Neil Brown
  23  *    Email: <neilb@suse.de>
  24  */
  25
  26 #include "wiggle.h"
  27 #include <stdlib.h>
  28
  29 /*
  30  * Second attempt at merging....
  31  *
  32  * We want to create a mergelist which identifies 'orig' and 'after'
  33  * sections (from a and c) and conflicts (which are ranges of a,b,c which
  34  * all don't match).
  35  * It is also helpful to differentiate 'orig' sections that aren't
  36  * matched in 'b' with orig sections that are.
  37  * To help with highlighting, it will be useful to know where
  38  * the conflicts match the csl lists.
  39  *
  40  * This can all be achieved with a list of (a,b,c,c1,c1) 5-tuples.
  41  * If two consecutive differ in more than one of a,b,c, it is a
  42  * conflict.
  43  * If only 'a' differ, it is un-matched original.
  44  * If only 'b' differ, it is matched, unchanged original
  45  * If only 'c' differ, it is 1
  46  */
  47
  48 static inline int min(int a, int b)
  49 {
  50         return a < b ? a : b;
  51 }
  52 static inline void assert(int a)
  53 {
  54         if (!a)
  55                 abort();
  56 }
  57
  58 static int check_alreadyapplied(struct file af, struct file cf,
  59                                 struct merge *m)
  60 {
  61         int i;
  62         if (m->al != m->cl)
  63                 return 0;
  64         for (i = 0; i < m->al; i++) {
  65                 if (af.list[m->a+i].len != cf.list[m->c+i].len)
  66                         return 0;
  67                 if (strncmp(af.list[m->a+i].start,
  68                             cf.list[m->c+i].start,
  69                             af.list[m->a+i].len) != 0)
  70                         return 0;
  71         }
  72         if (do_trace) {
  73                 printf("already applied %d,%d,%d - %d,%d,%d\n",
  74                        m->a, m->b, m->c, m->al, m->bl, m->cl);
  75                 printf(" %.10s - %.10s\n", af.list[m->a].start,
  76                        cf.list[m->c].start);
  77         }
  78         m->type = AlreadyApplied;
  79         return 1;
  80 }
  81
  82 /* A 'cut-point' is a location in the merger where it is reasonable
  83  * the change the mode of display - between displaying the merger
  84  * and displaying the separate streams.
  85  * A 'conflict' can only be displayed as separate stream so when
  86  * one is found, we need to find a preceeding and trailing cut-point
  87  * and enlarge the conflict to that range.
  88  * A suitable location is one where all three streams are at a line-end.
  89  */
  90 static int is_cutpoint(struct merge m,
  91                        struct file af, struct file bf, struct file cf)
  92 {
  93         return ((m.a == 0 || ends_line(af.list[m.a-1])) &&
  94                 (m.b == 0 || ends_line(bf.list[m.b-1])) &&
  95                 (m.c == 0 || ends_line(cf.list[m.c-1])));
  96 }
  97
  98 static int isolate_conflicts(struct file af, struct file bf, struct file cf,
  99                              struct csl *csl1, struct csl *csl2, int words,
 100                              struct merge *m, int show_wiggles)
 101 {
 102         /* A conflict indicates that something is definitely wrong
 103          * and so we need to be a bit suspicious of nearby apparent matches.
 104          * To display a conflict effectively we expands it's effect to
 105          * include any Extraneous, Unmatched, Changed or AlreadyApplied text.
 106          * Also, unless 'words', we need to include any partial lines
 107          * in the Unchanged text that forms the border of a conflict.
 108          *
 109          * A Changed text may also border a conflict, but it can
 110          * only border one conflict (where as an Unchanged can border
 111          * a preceeding and a following conflict).
 112          * The 'new' section of a Changed text appears in the
 113          * conflict as does any part of the original before
 114          * a newline.
 115          *
 116          * If 'show_wiggles' is set we treat wiggles like conflicts.
 117          * A 'wiggle' is implied by any Extraneous text being ignored,
 118          * or any line that has both Changed and Unmatched content.
 119          * (Unmatched content where nothing is changed is common and not
 120          *  really a 'wiggle').
 121          *
 122          * A hunk header is never considered part of a conflict.  It
 123          * thereby can serve as a separator between conflicts.
 124          *
 125          * We need to ensure there is adequate context for the conflict.
 126          * So ensure there are at least 3 newlines in Extraneous or
 127          * Unchanged on both sides of a Conflict - but don't go so far
 128          * as including a hunk header.
 129          * If there are 3, and they are all in 'Unchanged' sections, then
 130          * that much context is not really needed - reduce it a bit.
 131          */
 132         int i, j, k;
 133         int cnt = 0;
 134         int changed = 0;
 135         int unmatched = 0;
 136
 137         for (i = 0; m[i].type != End; i++) {
 138                 if (m[i].type == Changed)
 139                         changed = 1;
 140                 if (m[i].type == Unmatched)
 141                         unmatched = 1;
 142                 if (m[i].type == Conflict ||
 143                     (show_wiggles && ((changed && unmatched)
 144                                         || m[i].type == Extraneous))) {
 145                         /* We have a conflict (or wiggle) here.
 146                          * First search backwards for an Unchanged marking
 147                          * things as in_conflict.  Then find the
 148                          * cut-point in the Unchanged.  If there isn't one,
 149                          * keep looking.
 150                          *
 151                          * Then search forward doing the same thing.
 152                          */
 153                         int newlines = 0;
 154                         cnt++;
 155                         m[i].in_conflict = 1;
 156                         j = i;
 157                         while (--j >= 0) {
 158                                 if (m[j].type == Extraneous &&
 159                                     bf.list[m[j].b].start[0] == '\0')
 160                                         /* hunk header - not conflict any more */
 161                                         break;
 162                                 if (!m[j].in_conflict) {
 163                                         m[j].in_conflict = 1;
 164                                         m[j].lo = 0;
 165                                 } else if (m[j].type == Changed) {
 166                                         /* This can no longer form a border */
 167                                         m[j].hi = -1;
 168                                         /* We merge these conflicts and stop searching */
 169                                         cnt--;
 170                                         break;
 171                                 }
 172                                 if (m[j].type == Extraneous) {
 173                                         for (k = m[j].bl; k > 0; k--)
 174                                                 if (ends_line(bf.list[m[j].b+k-1]))
 175                                                         newlines++;
 176                                 }
 177
 178                                 if (m[j].type == Unchanged || m[j].type == Changed) {
 179                                         /* If we find enough newlines in this section,
 180                                          * then we only really need 1, but would rather
 181                                          * it wasn't the first one.  'firstk' allows us
 182                                          * to track which newline we actually use
 183                                          */
 184                                         int firstk = m[j].al;
 185                                         if (words) {
 186                                                 m[j].hi = m[j].al;
 187                                                 break;
 188                                         }
 189                                         /* need to find the last line-break, which
 190                                          * might be after the last newline, if there
 191                                          * is one, or might be at the start
 192                                          */
 193                                         for (k = m[j].al; k > 0; k--)
 194                                                 if (ends_line(af.list[m[j].a+k-1])) {
 195                                                         if (firstk == m[j].al)
 196                                                                 firstk = k;
 197                                                         newlines++;
 198                                                         if (newlines >= 3) {
 199                                                                 k = firstk;
 200                                                                 break;
 201                                                         }
 202                                                 }
 203                                         if (k > 0)
 204                                                 m[j].hi = k;
 205                                         else if (is_cutpoint(m[j], af,bf,cf))
 206                                                 m[j].hi = 0;
 207                                         else
 208                                                 /* no start-of-line found... */
 209                                                 m[j].hi = -1;
 210                                         if (m[j].hi > 0 && m[j].type == Changed) {
 211                                                 /* this can only work if start is
 212                                                  * also a line break */
 213                                                 if (is_cutpoint(m[j], af,bf,cf))
 214                                                         /* ok */;
 215                                                 else
 216                                                         m[j].hi = -1;
 217                                         }
 218                                         if (m[j].hi >= 0)
 219                                                 break;
 220                                 }
 221                         }
 222
 223                         /* now the forward search */
 224                         newlines = 0;
 225                         for (j = i+1; m[j].type != End; j++) {
 226                                 if (m[j].type == Extraneous &&
 227                                     bf.list[m[j].b].start[0] == '\0')
 228                                         /* hunk header - not conflict any more */
 229                                         break;
 230                                 m[j].in_conflict = 1;
 231                                 if (m[j].type == Extraneous) {
 232                                         for (k = 0; k < m[j].bl; k++)
 233                                                 if (ends_line(bf.list[m[j].b+k]))
 234                                                         newlines++;
 235                                 }
 236                                 if (m[j].type == Unchanged || m[j].type == Changed) {
 237                                         m[j].hi = m[j].al;
 238                                         if (words) {
 239                                                 m[j].lo = 0;
 240                                                 break;
 241                                         }
 242                                         /* need to find a line-break, which might be at
 243                                          * the very beginning, or might be after the
 244                                          * first newline - if there is one
 245                                          */
 246                                         if (is_cutpoint(m[j], af,bf,cf))
 247                                                 m[j].lo = 0;
 248                                         else {
 249                                                 /* If we find enough newlines in this section,
 250                                                  * then we only really need 1, but would rather
 251                                                  * it wasn't the first one.  'firstk' allows us
 252                                                  * to track which newline we actually use
 253                                                  */
 254                                                 int firstk = 0;
 255                                                 for (k = 0 ; k < m[j].al ; k++)
 256                                                         if (ends_line(af.list[m[j].a+k])) {
 257                                                                 if (firstk == 0)
 258                                                                         firstk = k;
 259                                                                 newlines++;
 260                                                                 if (newlines >= 3) {
 261                                                                         k = firstk;
 262                                                                         break;
 263                                                                 }
 264                                                         }
 265                                                 if (k < m[j].al)
 266                                                         m[j].lo = k+1;
 267                                                 else
 268                                                         /* no start-of-line found */
 269                                                         m[j].lo = m[j].al+1;
 270                                         }
 271                                         if (m[j].lo <= m[j].al+1 && m[j].type == Changed) {
 272                                                 /* this can only work if the end is a line break */
 273                                                 if (is_cutpoint(m[j+1], af,bf,cf))
 274                                                         /* ok */;
 275                                                 else
 276                                                         m[j].lo = m[j].al+1;
 277                                         }
 278                                         if (m[j].lo < m[j].al+1)
 279                                                 break;
 280                                 }
 281                         }
 282                         i = j - 1;
 283                 }
 284                 if (ends_line(af.list[m[i].a+m[i].al-1])) {
 285                         unmatched = 0;
 286                         changed = 0;
 287                 }
 288         }
 289         return cnt;
 290 }
 291
 292 struct ci make_merger(struct file af, struct file bf, struct file cf,
 293                       struct csl *csl1, struct csl *csl2, int words,
 294                       int ignore_already, int show_wiggles)
 295 {
 296         /* find the wiggles and conflicts between csl1 and csl2
 297          */
 298         struct ci rv;
 299         int i, l;
 300         int a, b, c, c1, c2;
 301         int wiggle_found = 0;
 302
 303         rv.conflicts = rv.wiggles = rv.ignored = 0;
 304
 305         for (i = 0; csl1[i].len; i++)
 306                 ;
 307         l = i;
 308         for (i = 0; csl2[i].len; i++)
 309                 ;
 310         l += i;
 311         /* maybe a bit of slack at each end */
 312         l = l * 4 + 10;
 313
 314         rv.merger = xmalloc(sizeof(struct merge)*l);
 315
 316         a = b = c = c1 = c2 = 0;
 317         i = 0;
 318         while (1) {
 319                 int match1, match2;
 320                 match1 = (a >= csl1[c1].a && b >= csl1[c1].b); /* c1 doesn't match */
 321                 match2 = (b >= csl2[c2].a && c >= csl2[c2].b);
 322
 323                 rv.merger[i].a = a;
 324                 rv.merger[i].b = b;
 325                 rv.merger[i].c = c;
 326                 rv.merger[i].c1 = c1;
 327                 rv.merger[i].c2 = c2;
 328                 rv.merger[i].in_conflict = 0;
 329
 330                 if (!match1 && match2) {
 331                         /* This is either Unmatched or Extraneous - probably both.
 332                          * If the match2 is a hunk-header Extraneous, it must
 333                          * align with an end-of-line in 'a', so adjust endpoint
 334                          */
 335                         int newa = csl1[c1].a;
 336                         if (bf.list[b].start && bf.list[b].start[0] == '\0') {
 337                                 while (newa > a &&
 338                                        !ends_line(af.list[newa-1]))
 339                                         newa--;
 340                                 while (newa < af.elcnt && !(newa == 0 || ends_line(af.list[newa-1])))
 341                                         newa++;
 342                         }
 343                         if (a < newa) {
 344                                 /* some unmatched text */
 345                                 rv.merger[i].type = Unmatched;
 346                                 rv.merger[i].al = newa - a;
 347                                 rv.merger[i].bl = 0;
 348                                 rv.merger[i].cl = 0;
 349                                 wiggle_found++;
 350                         } else {
 351                                 int newb;
 352                                 int j;
 353                                 assert(b < csl1[c1].b);
 354                                 /* some Extraneous text */
 355                                 /* length is min of unmatched on left
 356                                  * and matched on right.
 357                                  * However a hunk-header must be an
 358                                  * Extraneous section by itself, so if this
 359                                  * start with one, the length is 1, and if
 360                                  * there is one in the middle, only take the
 361                                  * text up to there for now.
 362                                  */
 363                                 rv.merger[i].type = Extraneous;
 364                                 rv.merger[i].al = 0;
 365                                 newb = b +
 366                                         min(csl1[c1].b - b,
 367                                             csl2[c2].len - (b-csl2[c2].a));
 368                                 if (bf.list[b].start[0] == '\0')
 369                                         newb = b + 1;
 370                                 for (j = b; j < newb; j++) {
 371                                         if (bf.list[j].start[0] == '\0') {
 372                                                 if (wiggle_found > 1)
 373                                                         rv.wiggles++;
 374                                                 wiggle_found = 0;
 375                                                 if (j > b)
 376                                                         newb = j;
 377                                         } else
 378                                                 wiggle_found++;
 379                                 }
 380                                 rv.merger[i].cl =
 381                                         rv.merger[i].bl = newb - b;
 382                         }
 383                 } else if (match1 && !match2) {
 384                         /* some changed text
 385                          * if 'c' is currently at a suitable cut-point, then
 386                          * we can look for a triple-cut-point for start.
 387                          * Also, if csl2[c2].b isn't in a conflict, and is
 388                          * a suitable cut-point, then we could make a
 389                          * triple-cut-point for end of a conflict.
 390                          */
 391
 392                         rv.merger[i].type = Changed;
 393                         rv.merger[i].bl = min(csl1[c1].b+csl1[c1].len, csl2[c2].a) - b;
 394                         rv.merger[i].al = rv.merger[i].bl;
 395                         rv.merger[i].cl = csl2[c2].b - c;
 396                 } else if (match1 && match2) {
 397                         /* Some unchanged text
 398                          */
 399                         rv.merger[i].type = Unchanged;
 400                         rv.merger[i].bl =
 401                                 min(csl1[c1].len - (b-csl1[c1].b),
 402                                     csl2[c2].len - (b-csl2[c2].a));
 403                         rv.merger[i].al = rv.merger[i].cl =
 404                                 rv.merger[i].bl;
 405                 } else {
 406                         /* must be a conflict.
 407                          * Move a and c to next match, and b to closest of the two
 408                          */
 409                         rv.merger[i].type = Conflict;
 410                         rv.merger[i].al = csl1[c1].a - a;
 411                         rv.merger[i].cl = csl2[c2].b - c;
 412                         rv.merger[i].bl = min(csl1[c1].b, csl2[c2].a) - b;
 413                         if (ignore_already &&
 414                             check_alreadyapplied(af, cf, &rv.merger[i]))
 415                                 rv.ignored++;
 416                 }
 417                 a += rv.merger[i].al;
 418                 b += rv.merger[i].bl;
 419                 c += rv.merger[i].cl;
 420                 i++;
 421
 422                 while (csl1[c1].a + csl1[c1].len <= a && csl1[c1].len)
 423                         c1++;
 424                 assert(csl1[c1].b + csl1[c1].len >= b);
 425                 while (csl2[c2].b + csl2[c2].len <= c && csl2[c2].len)
 426                         c2++;
 427                 assert(csl2[c2].a + csl2[c2].len >= b);
 428                 if (csl1[c1].len == 0 && csl2[c2].len == 0 &&
 429                     a == csl1[c1].a && b == csl1[c1].b &&
 430                     b == csl2[c2].a && c == csl2[c2].b)
 431                         break;
 432         }
 433         rv.merger[i].type = End;
 434         rv.merger[i].in_conflict = 0;
 435         assert(i < l);
 436         rv.conflicts = isolate_conflicts(af, bf, cf, csl1, csl2, words,
 437                                          rv.merger, show_wiggles);
 438         if (wiggle_found)
 439                 rv.wiggles++;
 440         return rv;
 441 }
 442
 443 static void printrange(FILE *out, struct file *f, int start, int len)
 444 {
 445         while (len > 0) {
 446                 printword(out, f->list[start]);
 447                 start++;
 448                 len--;
 449         }
 450 }
 451
 452 struct ci print_merge2(FILE *out, struct file *a, struct file *b, struct file *c,
 453                        struct csl *c1, struct csl *c2,
 454                        int words, int ignore_already, int show_wiggles)
 455 {
 456         struct ci rv = make_merger(*a, *b, *c, c1, c2,
 457                                    words, ignore_already, show_wiggles);
 458         struct merge *m;
 459
 460         for (m = rv.merger; m->type != End ; m++) {
 461                 struct merge *cm;
 462                 if (do_trace)
 463                         printf("[%s: %d-%d,%d-%d,%d-%d%s(%d,%d)]\n",
 464                                m->type==Unmatched ? "Unmatched" :
 465                                m->type==Unchanged ? "Unchanged" :
 466                                m->type==Extraneous ? "Extraneous" :
 467                                m->type==Changed ? "Changed" :
 468                                m->type==AlreadyApplied ? "AlreadyApplied" :
 469                                m->type==Conflict ? "Conflict":"unknown",
 470                                m->a, m->a+m->al-1,
 471                                m->b, m->b+m->bl-1,
 472                                m->c, m->c+m->cl-1,
 473                                m->in_conflict ? " in_conflict" : "",
 474                                m->lo, m->hi);
 475
 476                 while (m->in_conflict) {
 477                         /* need to print from 'hi' to 'lo' of next
 478                          * Unchanged which is < it's hi
 479                          */
 480                         int found_conflict = 0;
 481                         int st = 0, st1;
 482                         if (m->type == Unchanged || m->type == Changed)
 483                                 if (m->hi >= m->lo)
 484                                         st = m->hi;
 485                         st1 = st;
 486
 487                         if (m->type == Unchanged)
 488                                 printrange(out, a, m->a+m->lo, m->hi - m->lo);
 489
 490                         if (do_trace)
 491                                 for (cm = m; cm->in_conflict; cm++) {
 492                                         printf("{%s: %d-%d,%d-%d,%d-%d%s(%d,%d)}\n",
 493                                                cm->type==Unmatched?"Unmatched":
 494                                                cm->type==Unchanged?"Unchanged":
 495                                                cm->type==Extraneous?"Extraneous":
 496                                                cm->type==Changed?"Changed":
 497                                                cm->type==AlreadyApplied?"AlreadyApplied":
 498                                                cm->type==Conflict?"Conflict":"unknown",
 499                                                cm->a, cm->a+cm->al-1,
 500                                                cm->b, cm->b+cm->bl-1,
 501                                                cm->c, cm->c+cm->cl-1,
 502                                                cm->in_conflict ? " in_conflict" : "",
 503                                                cm->lo, cm->hi);
 504                                         if ((cm->type == Unchanged || cm->type == Changed)
 505                                             && cm != m && cm->lo < cm->hi)
 506                                                 break;
 507                                 }
 508
 509                         fputs(words ? "<<<---" : "<<<<<<<\n", out);
 510                         for (cm = m; cm->in_conflict; cm++) {
 511                                 if (cm->type == Conflict)
 512                                         found_conflict = 1;
 513                                 if ((cm->type == Unchanged || cm->type == Changed)
 514                                     && cm != m && cm->lo < cm->hi) {
 515                                         printrange(out, a, cm->a, cm->lo);
 516                                         break;
 517                                 }
 518                                 printrange(out, a, cm->a+st1, cm->al-st1);
 519                                 st1 = 0;
 520                         }
 521                         fputs(words ? "|||" : "|||||||\n", out);
 522                         st1 = st;
 523                         for (cm = m; cm->in_conflict; cm++) {
 524                                 if ((cm->type == Unchanged || cm->type == Changed)
 525                                     && cm != m && cm->lo < cm->hi) {
 526                                         printrange(out, b, cm->b, cm->lo);
 527                                         break;
 528                                 }
 529                                 printrange(out, b, cm->b+st1, cm->bl-st1);
 530                                 st1 = 0;
 531                         }
 532                         fputs(words ? "===" : "=======\n", out);
 533                         st1 = st;
 534                         for (cm = m; cm->in_conflict; cm++) {
 535                                 if (cm->type == Unchanged &&
 536                                     cm != m && cm->lo < cm->hi) {
 537                                         printrange(out, c, cm->c, cm->lo);
 538                                         break;
 539                                 }
 540                                 if (cm->type == Changed)
 541                                         st1 = 0; /* All of result of change must be printed */
 542                                 printrange(out, c, cm->c+st1, cm->cl-st1);
 543                                 st1 = 0;
 544                         }
 545                         if (!found_conflict) {
 546                                 /* This section was wiggled in successfully,
 547                                  * but full conflict display was requested.
 548                                  * So now print out the wiggled result as well.
 549                                  */
 550                                 fputs(words ? "&&&" : "&&&&&&&\n", out);
 551                                 st1 = st;
 552                                 for (cm = m; cm->in_conflict; cm++) {
 553                                         int last = 0;
 554                                         if ((cm->type == Unchanged || cm->type == Changed)
 555                                             && cm != m && cm->lo < cm->hi)
 556                                                 last = 1;
 557                                         switch (cm->type) {
 558                                         case Unchanged:
 559                                         case AlreadyApplied:
 560                                         case Unmatched:
 561                                                 printrange(out, a, cm->a+st1,
 562                                                            last ? cm->lo : cm->al-st1);
 563                                                 break;
 564                                         case Extraneous:
 565                                                 break;
 566                                         case Changed:
 567                                                 printrange(out, c, cm->c+st1,
 568                                                            last ? cm->lo : cm->cl-st1);
 569                                                 break;
 570                                         case Conflict:
 571                                         case End:
 572                                                 assert(0);
 573                                         }
 574                                         if (last)
 575                                                 break;
 576                                         st1 = 0;
 577                                 }
 578                         }
 579                         fputs(words ? "--->>>" : ">>>>>>>\n", out);
 580                         m = cm;
 581                         if (m->in_conflict && m->type == Unchanged
 582                             && m->hi >= m->al) {
 583                                 printrange(out, a, m->a+m->lo, m->hi-m->lo);
 584                                 m++;
 585                         }
 586                 }
 587
 588                 /* there is always some non-conflict after a conflict,
 589                  * unless we hit the end
 590                  */
 591                 if (m->type == End)
 592                         break;
 593
 594                 if (do_trace) {
 595                         printf("<<%s: %d-%d,%d-%d,%d-%d%s(%d,%d)>>\n",
 596                                m->type==Unmatched?"Unmatched":
 597                                m->type==Unchanged?"Unchanged":
 598                                m->type==Extraneous?"Extraneous":
 599                                m->type==Changed?"Changed":
 600                                m->type==AlreadyApplied?"AlreadyApplied":
 601                                m->type==Conflict?"Conflict":"unknown",
 602                                m->a, m->a+m->al-1,
 603                                m->b, m->b+m->bl-1,
 604                                m->c, m->c+m->cl-1,
 605                                m->in_conflict ? " in_conflict" : "",
 606                                m->lo, m->hi);
 607                 }
 608
 609                 switch (m->type) {
 610                 case Unchanged:
 611                 case AlreadyApplied:
 612                 case Unmatched:
 613                         printrange(out, a, m->a, m->al);
 614                         break;
 615                 case Extraneous:
 616                         break;
 617                 case Changed:
 618                         printrange(out, c, m->c, m->cl);
 619                         break;
 620                 case Conflict:
 621                 case End:
 622                         assert(0);
 623                 }
 624         }
 625         return rv;
 626 }