xmerge.c 18 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
/*
 *  LibXDiff by Davide Libenzi ( File Differential Library )
 *  Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
16 17
 *  License along with this library; if not, see
 *  <http://www.gnu.org/licenses/>.
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111
 *
 *  Davide Libenzi <davidel@xmailserver.org>
 *
 */

#include "xinclude.h"

typedef struct s_xdmerge {
	struct s_xdmerge *next;
	/*
	 * 0 = conflict,
	 * 1 = no conflict, take first,
	 * 2 = no conflict, take second.
	 * 3 = no conflict, take both.
	 */
	int mode;
	/*
	 * These point at the respective postimages.  E.g. <i1,chg1> is
	 * how side #1 wants to change the common ancestor; if there is no
	 * overlap, lines before i1 in the postimage of side #1 appear
	 * in the merge result as a region touched by neither side.
	 */
	long i1, i2;
	long chg1, chg2;
	/*
	 * These point at the preimage; of course there is just one
	 * preimage, that is from the shared common ancestor.
	 */
	long i0;
	long chg0;
} xdmerge_t;

static int xdl_append_merge(xdmerge_t **merge, int mode,
			    long i0, long chg0,
			    long i1, long chg1,
			    long i2, long chg2)
{
	xdmerge_t *m = *merge;
	if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
		if (mode != m->mode)
			m->mode = 0;
		m->chg0 = i0 + chg0 - m->i0;
		m->chg1 = i1 + chg1 - m->i1;
		m->chg2 = i2 + chg2 - m->i2;
	} else {
		m = xdl_malloc(sizeof(xdmerge_t));
		if (!m)
			return -1;
		m->next = NULL;
		m->mode = mode;
		m->i0 = i0;
		m->chg0 = chg0;
		m->i1 = i1;
		m->chg1 = chg1;
		m->i2 = i2;
		m->chg2 = chg2;
		if (*merge)
			(*merge)->next = m;
		*merge = m;
	}
	return 0;
}

static int xdl_cleanup_merge(xdmerge_t *c)
{
	int count = 0;
	xdmerge_t *next_c;

	/* were there conflicts? */
	for (; c; c = next_c) {
		if (c->mode == 0)
			count++;
		next_c = c->next;
		free(c);
	}
	return count;
}

static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
		int line_count, long flags)
{
	int i;
	xrecord_t **rec1 = xe1->xdf2.recs + i1;
	xrecord_t **rec2 = xe2->xdf2.recs + i2;

	for (i = 0; i < line_count; i++) {
		int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
			rec2[i]->ptr, rec2[i]->size, flags);
		if (!result)
			return -1;
	}
	return 0;
}

112
static int xdl_recs_copy_0(size_t *out, int use_orig, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
113 114
{
	xrecord_t **recs;
115 116 117
	size_t size = 0;

	*out = 0;
118 119 120 121 122 123

	recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;

	if (count < 1)
		return 0;

124
	for (i = 0; i < count; ) {
125 126
		if (dest)
			memcpy(dest + size, recs[i]->ptr, recs[i]->size);
127 128 129 130

		GITERR_CHECK_ALLOC_ADD(&size, size, recs[i++]->size);
	}

131 132 133
	if (add_nl) {
		i = recs[count - 1]->size;
		if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
134 135 136 137 138 139
			if (needs_cr) {
				if (dest)
					dest[size] = '\r';
				GITERR_CHECK_ALLOC_ADD(&size, size, 1);
			}

140 141
			if (dest)
				dest[size] = '\n';
142 143

			GITERR_CHECK_ALLOC_ADD(&size, size, 1);
144 145
		}
	}
146 147 148

	*out = size;
	return 0;
149 150
}

151
static int xdl_recs_copy(size_t *out, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
152
{
153
	return xdl_recs_copy_0(out, 0, xe, i, count, needs_cr, add_nl, dest);
154 155
}

156
static int xdl_orig_copy(size_t *out, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
157
{
158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
	return xdl_recs_copy_0(out, 1, xe, i, count, needs_cr, add_nl, dest);
}

/*
 * Returns 1 if the i'th line ends in CR/LF (if it is the last line and
 * has no eol, the preceding line, if any), 0 if it ends in LF-only, and
 * -1 if the line ending cannot be determined.
 */
static int is_eol_crlf(xdfile_t *file, int i)
{
	long size;

	if (i < file->nrec - 1)
		/* All lines before the last *must* end in LF */
		return (size = file->recs[i]->size) > 1 &&
			file->recs[i]->ptr[size - 2] == '\r';
	if (!file->nrec)
		/* Cannot determine eol style from empty file */
		return -1;
	if ((size = file->recs[i]->size) &&
			file->recs[i]->ptr[size - 1] == '\n')
		/* Last line; ends in LF; Is it CR/LF? */
		return size > 1 &&
			file->recs[i]->ptr[size - 2] == '\r';
	if (!i)
		/* The only line has no eol */
		return -1;
	/* Determine eol from second-to-last line */
	return (size = file->recs[i - 1]->size) > 1 &&
		file->recs[i - 1]->ptr[size - 2] == '\r';
}

static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
{
	int needs_cr;

	/* Match post-images' preceding, or first, lines' end-of-line style */
	needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
	if (needs_cr)
		needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
	/* Look at pre-image's first line, unless we already settled on LF */
	if (needs_cr)
		needs_cr = is_eol_crlf(&xe1->xdf1, 0);
	/* If still undecided, use LF-only */
	return needs_cr < 0 ? 0 : needs_cr;
203 204
}

205
static int fill_conflict_hunk(size_t *out, xdfenv_t *xe1, const char *name1,
206 207
			      xdfenv_t *xe2, const char *name2,
			      const char *name3,
208
			      size_t size, int i, int style,
209 210
			      xdmerge_t *m, char *dest, int marker_size)
{
211 212 213
	int marker1_size = (name1 ? (int)strlen(name1) + 1 : 0);
	int marker2_size = (name2 ? (int)strlen(name2) + 1 : 0);
	int marker3_size = (name3 ? (int)strlen(name3) + 1 : 0);
214
	int needs_cr = is_cr_needed(xe1, xe2, m);
215 216 217
	size_t copied;

	*out = 0;
218 219 220 221 222

	if (marker_size <= 0)
		marker_size = DEFAULT_CONFLICT_MARKER_SIZE;

	/* Before conflicting part */
223
	if (xdl_recs_copy(&copied, xe1, i, m->i1 - i, 0, 0,
224 225 226 227
			      dest ? dest + size : NULL) < 0)
		return -1;

	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
228 229

	if (!dest) {
230
		GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr,  marker1_size);
231 232 233 234 235 236 237 238
	} else {
		memset(dest + size, '<', marker_size);
		size += marker_size;
		if (marker1_size) {
			dest[size] = ' ';
			memcpy(dest + size + 1, name1, marker1_size - 1);
			size += marker1_size;
		}
239 240
		if (needs_cr)
			dest[size++] = '\r';
241 242 243 244
		dest[size++] = '\n';
	}

	/* Postimage from side #1 */
245
	if (xdl_recs_copy(&copied, xe1, m->i1, m->chg1, needs_cr, 1,
246 247 248 249
			      dest ? dest + size : NULL) < 0)
		return -1;

	GITERR_CHECK_ALLOC_ADD(&size, size, copied);
250 251 252 253

	if (style == XDL_MERGE_DIFF3) {
		/* Shared preimage */
		if (!dest) {
254
			GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr, marker3_size);
255 256 257 258 259 260 261 262
		} else {
			memset(dest + size, '|', marker_size);
			size += marker_size;
			if (marker3_size) {
				dest[size] = ' ';
				memcpy(dest + size + 1, name3, marker3_size - 1);
				size += marker3_size;
			}
263 264
			if (needs_cr)
				dest[size++] = '\r';
265 266
			dest[size++] = '\n';
		}
267

268
		if (xdl_orig_copy(&copied, xe1, m->i0, m->chg0, needs_cr, 1,
269 270 271
				      dest ? dest + size : NULL) < 0)
			return -1;
		GITERR_CHECK_ALLOC_ADD(&size, size, copied);
272 273 274
	}

	if (!dest) {
275
		GITERR_CHECK_ALLOC_ADD4(&size, size, marker_size, 1, needs_cr);
276 277 278
	} else {
		memset(dest + size, '=', marker_size);
		size += marker_size;
279 280
		if (needs_cr)
			dest[size++] = '\r';
281 282 283 284
		dest[size++] = '\n';
	}

	/* Postimage from side #2 */
285

286
	if (xdl_recs_copy(&copied, xe2, m->i2, m->chg2, needs_cr, 1,
287 288 289 290
			      dest ? dest + size : NULL) < 0)
		return -1;
	GITERR_CHECK_ALLOC_ADD(&size, size, copied);

291
	if (!dest) {
292
		GITERR_CHECK_ALLOC_ADD5(&size, size, marker_size, 1, needs_cr, marker2_size);
293 294 295 296 297 298 299 300
	} else {
		memset(dest + size, '>', marker_size);
		size += marker_size;
		if (marker2_size) {
			dest[size] = ' ';
			memcpy(dest + size + 1, name2, marker2_size - 1);
			size += marker2_size;
		}
301 302
		if (needs_cr)
			dest[size++] = '\r';
303 304
		dest[size++] = '\n';
	}
305 306 307

	*out = size;
	return 0;
308 309
}

310 311
static int xdl_fill_merge_buffer(size_t *out,
				 xdfenv_t *xe1, const char *name1,
312 313 314 315 316 317
				 xdfenv_t *xe2, const char *name2,
				 const char *ancestor_name,
				 int favor,
				 xdmerge_t *m, char *dest, int style,
				 int marker_size)
{
318 319 320 321
	size_t size, copied;
	int i;

	*out = 0;
322 323 324 325 326

	for (size = i = 0; m; m = m->next) {
		if (favor && !m->mode)
			m->mode = favor;

327 328
		if (m->mode == 0) {
			if (fill_conflict_hunk(&size, xe1, name1, xe2, name2,
329 330
						  ancestor_name,
						  size, i, style, m, dest,
331 332 333
						  marker_size) < 0)
				return -1;
		}
334 335
		else if (m->mode & 3) {
			/* Before conflicting part */
336
			if (xdl_recs_copy(&copied, xe1, i, m->i1 - i, 0, 0,
337 338 339 340
					      dest ? dest + size : NULL) < 0)
				return -1;
			GITERR_CHECK_ALLOC_ADD(&size, size, copied);

341
			/* Postimage from side #1 */
342
			if (m->mode & 1) {
343 344 345
				int needs_cr = is_cr_needed(xe1, xe2, m);

				if (xdl_recs_copy(&copied, xe1, m->i1, m->chg1, needs_cr, (m->mode & 2),
346 347 348 349 350
						      dest ? dest + size : NULL) < 0)
					return -1;
				GITERR_CHECK_ALLOC_ADD(&size, size, copied);
			}

351
			/* Postimage from side #2 */
352
			if (m->mode & 2) {
353
				if (xdl_recs_copy(&copied, xe2, m->i2, m->chg2, 0, 0,
354 355 356 357
						      dest ? dest + size : NULL) < 0)
					return -1;
				GITERR_CHECK_ALLOC_ADD(&size, size, copied);
			}
358 359 360 361
		} else
			continue;
		i = m->i1 + m->chg1;
	}
362

363
	if (xdl_recs_copy(&copied, xe1, i, xe1->xdf2.nrec - i, 0, 0,
364 365 366 367 368 369
			      dest ? dest + size : NULL) < 0)
		return -1;
	GITERR_CHECK_ALLOC_ADD(&size, size, copied);

	*out = size;
	return 0;
370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662
}

/*
 * Sometimes, changes are not quite identical, but differ in only a few
 * lines. Try hard to show only these few lines as conflicting.
 */
static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
		xpparam_t const *xpp)
{
	for (; m; m = m->next) {
		mmfile_t t1, t2;
		xdfenv_t xe;
		xdchange_t *xscr, *x;
		int i1 = m->i1, i2 = m->i2;

		/* let's handle just the conflicts */
		if (m->mode)
			continue;

		/* no sense refining a conflict when one side is empty */
		if (m->chg1 == 0 || m->chg2 == 0)
			continue;

		/*
		 * This probably does not work outside git, since
		 * we have a very simple mmfile structure.
		 */
		t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
		t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
		t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
		t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
		if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
			return -1;
		if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
		    xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
		    xdl_build_script(&xe, &xscr) < 0) {
			xdl_free_env(&xe);
			return -1;
		}
		if (!xscr) {
			/* If this happens, the changes are identical. */
			xdl_free_env(&xe);
			m->mode = 4;
			continue;
		}
		x = xscr;
		m->i1 = xscr->i1 + i1;
		m->chg1 = xscr->chg1;
		m->i2 = xscr->i2 + i2;
		m->chg2 = xscr->chg2;
		while (xscr->next) {
			xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
			if (!m2) {
				xdl_free_env(&xe);
				xdl_free_script(x);
				return -1;
			}
			xscr = xscr->next;
			m2->next = m->next;
			m->next = m2;
			m = m2;
			m->mode = 0;
			m->i1 = xscr->i1 + i1;
			m->chg1 = xscr->chg1;
			m->i2 = xscr->i2 + i2;
			m->chg2 = xscr->chg2;
		}
		xdl_free_env(&xe);
		xdl_free_script(x);
	}
	return 0;
}

static int line_contains_alnum(const char *ptr, long size)
{
	while (size--)
		if (isalnum((unsigned char)*(ptr++)))
			return 1;
	return 0;
}

static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
{
	for (; chg; chg--, i++)
		if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
				xe->xdf2.recs[i]->size))
			return 1;
	return 0;
}

/*
 * This function merges m and m->next, marking everything between those hunks
 * as conflicting, too.
 */
static void xdl_merge_two_conflicts(xdmerge_t *m)
{
	xdmerge_t *next_m = m->next;
	m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
	m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
	m->next = next_m->next;
	free(next_m);
}

/*
 * If there are less than 3 non-conflicting lines between conflicts,
 * it appears simpler -- because it takes up less (or as many) lines --
 * if the lines are moved into the conflicts.
 */
static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
				      int simplify_if_no_alnum)
{
	int result = 0;

	if (!m)
		return result;
	for (;;) {
		xdmerge_t *next_m = m->next;
		int begin, end;

		if (!next_m)
			return result;

		begin = m->i1 + m->chg1;
		end = next_m->i1;

		if (m->mode != 0 || next_m->mode != 0 ||
		    (end - begin > 3 &&
		     (!simplify_if_no_alnum ||
		      lines_contain_alnum(xe1, begin, end - begin)))) {
			m = next_m;
		} else {
			result++;
			xdl_merge_two_conflicts(m);
		}
	}
}

/*
 * level == 0: mark all overlapping changes as conflict
 * level == 1: mark overlapping changes as conflict only if not identical
 * level == 2: analyze non-identical changes for minimal conflict set
 * level == 3: analyze non-identical changes for minimal conflict set, but
 *             treat hunks not containing any letter or number as conflicting
 *
 * returns < 0 on error, == 0 for no conflicts, else number of conflicts
 */
static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1,
		xdfenv_t *xe2, xdchange_t *xscr2,
		xmparam_t const *xmp, mmbuffer_t *result)
{
	xdmerge_t *changes, *c;
	xpparam_t const *xpp = &xmp->xpp;
	const char *const ancestor_name = xmp->ancestor;
	const char *const name1 = xmp->file1;
	const char *const name2 = xmp->file2;
	int i0, i1, i2, chg0, chg1, chg2;
	int level = xmp->level;
	int style = xmp->style;
	int favor = xmp->favor;

	if (style == XDL_MERGE_DIFF3) {
		/*
		 * "diff3 -m" output does not make sense for anything
		 * more aggressive than XDL_MERGE_EAGER.
		 */
		if (XDL_MERGE_EAGER < level)
			level = XDL_MERGE_EAGER;
	}

	c = changes = NULL;

	while (xscr1 && xscr2) {
		if (!changes)
			changes = c;
		if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
			i0 = xscr1->i1;
			i1 = xscr1->i2;
			i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
			chg0 = xscr1->chg1;
			chg1 = xscr1->chg2;
			chg2 = xscr1->chg1;
			if (xdl_append_merge(&c, 1,
					     i0, chg0, i1, chg1, i2, chg2)) {
				xdl_cleanup_merge(changes);
				return -1;
			}
			xscr1 = xscr1->next;
			continue;
		}
		if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
			i0 = xscr2->i1;
			i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
			i2 = xscr2->i2;
			chg0 = xscr2->chg1;
			chg1 = xscr2->chg1;
			chg2 = xscr2->chg2;
			if (xdl_append_merge(&c, 2,
					     i0, chg0, i1, chg1, i2, chg2)) {
				xdl_cleanup_merge(changes);
				return -1;
			}
			xscr2 = xscr2->next;
			continue;
		}
		if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
				xscr1->chg1 != xscr2->chg1 ||
				xscr1->chg2 != xscr2->chg2 ||
				xdl_merge_cmp_lines(xe1, xscr1->i2,
					xe2, xscr2->i2,
					xscr1->chg2, xpp->flags)) {
			/* conflict */
			int off = xscr1->i1 - xscr2->i1;
			int ffo = off + xscr1->chg1 - xscr2->chg1;

			i0 = xscr1->i1;
			i1 = xscr1->i2;
			i2 = xscr2->i2;
			if (off > 0) {
				i0 -= off;
				i1 -= off;
			}
			else
				i2 += off;
			chg0 = xscr1->i1 + xscr1->chg1 - i0;
			chg1 = xscr1->i2 + xscr1->chg2 - i1;
			chg2 = xscr2->i2 + xscr2->chg2 - i2;
			if (ffo < 0) {
				chg0 -= ffo;
				chg1 -= ffo;
			} else
				chg2 += ffo;
			if (xdl_append_merge(&c, 0,
					     i0, chg0, i1, chg1, i2, chg2)) {
				xdl_cleanup_merge(changes);
				return -1;
			}
		}

		i1 = xscr1->i1 + xscr1->chg1;
		i2 = xscr2->i1 + xscr2->chg1;

		if (i1 >= i2)
			xscr2 = xscr2->next;
		if (i2 >= i1)
			xscr1 = xscr1->next;
	}
	while (xscr1) {
		if (!changes)
			changes = c;
		i0 = xscr1->i1;
		i1 = xscr1->i2;
		i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
		chg0 = xscr1->chg1;
		chg1 = xscr1->chg2;
		chg2 = xscr1->chg1;
		if (xdl_append_merge(&c, 1,
				     i0, chg0, i1, chg1, i2, chg2)) {
			xdl_cleanup_merge(changes);
			return -1;
		}
		xscr1 = xscr1->next;
	}
	while (xscr2) {
		if (!changes)
			changes = c;
		i0 = xscr2->i1;
		i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
		i2 = xscr2->i2;
		chg0 = xscr2->chg1;
		chg1 = xscr2->chg1;
		chg2 = xscr2->chg2;
		if (xdl_append_merge(&c, 2,
				     i0, chg0, i1, chg1, i2, chg2)) {
			xdl_cleanup_merge(changes);
			return -1;
		}
		xscr2 = xscr2->next;
	}
	if (!changes)
		changes = c;
	/* refine conflicts */
	if (XDL_MERGE_ZEALOUS <= level &&
	    (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
	     xdl_simplify_non_conflicts(xe1, changes,
					XDL_MERGE_ZEALOUS < level) < 0)) {
		xdl_cleanup_merge(changes);
		return -1;
	}
	/* output */
	if (result) {
		int marker_size = xmp->marker_size;
663 664 665
		size_t size;

		if (xdl_fill_merge_buffer(&size, xe1, name1, xe2, name2,
666 667
						 ancestor_name,
						 favor, changes, NULL, style,
668 669 670
						 marker_size) < 0)
			return -1;

671 672 673 674 675 676
		result->ptr = xdl_malloc(size);
		if (!result->ptr) {
			xdl_cleanup_merge(changes);
			return -1;
		}
		result->size = size;
677
		if (xdl_fill_merge_buffer(&size, xe1, name1, xe2, name2,
678
				      ancestor_name, favor, changes,
679 680
				      result->ptr, style, marker_size) < 0)
			return -1;
681 682 683 684 685 686 687 688 689 690 691 692 693 694 695
	}
	return xdl_cleanup_merge(changes);
}

int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
		xmparam_t const *xmp, mmbuffer_t *result)
{
	xdchange_t *xscr1, *xscr2;
	xdfenv_t xe1, xe2;
	int status;
	xpparam_t const *xpp = &xmp->xpp;

	result->ptr = NULL;
	result->size = 0;

696 697 698 699 700
	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0) {
		return -1;
	}
	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
		xdl_free_env(&xe1);
701 702 703 704 705 706 707 708 709 710 711
		return -1;
	}
	if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
	    xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
	    xdl_build_script(&xe1, &xscr1) < 0) {
		xdl_free_env(&xe1);
		return -1;
	}
	if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
	    xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
	    xdl_build_script(&xe2, &xscr2) < 0) {
712 713
		xdl_free_script(xscr1);
		xdl_free_env(&xe1);
714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738
		xdl_free_env(&xe2);
		return -1;
	}
	status = 0;
	if (!xscr1) {
		result->ptr = xdl_malloc(mf2->size);
		memcpy(result->ptr, mf2->ptr, mf2->size);
		result->size = mf2->size;
	} else if (!xscr2) {
		result->ptr = xdl_malloc(mf1->size);
		memcpy(result->ptr, mf1->ptr, mf1->size);
		result->size = mf1->size;
	} else {
		status = xdl_do_merge(&xe1, xscr1,
				      &xe2, xscr2,
				      xmp, result);
	}
	xdl_free_script(xscr1);
	xdl_free_script(xscr2);

	xdl_free_env(&xe1);
	xdl_free_env(&xe2);

	return status;
}