git

1
/*
2
 *  LibXDiff by Davide Libenzi ( File Differential Library )
3
 *  Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
4
 *
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 *  This library is free software; you can redistribute it and/or
6
 *  modify it under the terms of the GNU Lesser General Public
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 *  License as published by the Free Software Foundation; either
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 *  version 2.1 of the License, or (at your option) any later version.
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 *
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 *  This library is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 *  Lesser General Public License for more details.
14
 *
15
 *  You should have received a copy of the GNU Lesser General Public
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 *  License along with this library; if not, see
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 *  <http://www.gnu.org/licenses/>.
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 *
19
 *  Davide Libenzi <davidel@xmailserver.org>
20
 *
21
 */
22

23
#include "xinclude.h"
24

25
typedef struct s_xdmerge {
26
	struct s_xdmerge *next;
27
	/*
28
	 * 0 = conflict,
29
	 * 1 = no conflict, take first,
30
	 * 2 = no conflict, take second.
31
	 * 3 = no conflict, take both.
32
	 */
33
	int mode;
34
	/*
35
	 * These point at the respective postimages.  E.g. <i1,chg1> is
36
	 * how side #1 wants to change the common ancestor; if there is no
37
	 * overlap, lines before i1 in the postimage of side #1 appear
38
	 * in the merge result as a region touched by neither side.
39
	 */
40
	long i1, i2;
41
	long chg1, chg2;
42
	/*
43
	 * These point at the preimage; of course there is just one
44
	 * preimage, that is from the shared common ancestor.
45
	 */
46
	long i0;
47
	long chg0;
48
} xdmerge_t;
49

50
static int xdl_append_merge(xdmerge_t **merge, int mode,
51
			    long i0, long chg0,
52
			    long i1, long chg1,
53
			    long i2, long chg2)
54
{
55
	xdmerge_t *m = *merge;
56
	if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
57
		if (mode != m->mode)
58
			m->mode = 0;
59
		m->chg0 = i0 + chg0 - m->i0;
60
		m->chg1 = i1 + chg1 - m->i1;
61
		m->chg2 = i2 + chg2 - m->i2;
62
	} else {
63
		m = xdl_malloc(sizeof(xdmerge_t));
64
		if (!m)
65
			return -1;
66
		m->next = NULL;
67
		m->mode = mode;
68
		m->i0 = i0;
69
		m->chg0 = chg0;
70
		m->i1 = i1;
71
		m->chg1 = chg1;
72
		m->i2 = i2;
73
		m->chg2 = chg2;
74
		if (*merge)
75
			(*merge)->next = m;
76
		*merge = m;
77
	}
78
	return 0;
79
}
80

81
static int xdl_cleanup_merge(xdmerge_t *c)
82
{
83
	int count = 0;
84
	xdmerge_t *next_c;
85

86
	/* were there conflicts? */
87
	for (; c; c = next_c) {
88
		if (c->mode == 0)
89
			count++;
90
		next_c = c->next;
91
		free(c);
92
	}
93
	return count;
94
}
95

96
static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
97
		int line_count, long flags)
98
{
99
	int i;
100
	xrecord_t **rec1 = xe1->xdf2.recs + i1;
101
	xrecord_t **rec2 = xe2->xdf2.recs + i2;
102

103
	for (i = 0; i < line_count; i++) {
104
		int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
105
			rec2[i]->ptr, rec2[i]->size, flags);
106
		if (!result)
107
			return -1;
108
	}
109
	return 0;
110
}
111

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

117
	recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
118

119
	if (count < 1)
120
		return 0;
121

122
	for (i = 0; i < count; size += recs[i++]->size)
123
		if (dest)
124
			memcpy(dest + size, recs[i]->ptr, recs[i]->size);
125
	if (add_nl) {
126
		i = recs[count - 1]->size;
127
		if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
128
			if (needs_cr) {
129
				if (dest)
130
					dest[size] = '\r';
131
				size++;
132
			}
133

134
			if (dest)
135
				dest[size] = '\n';
136
			size++;
137
		}
138
	}
139
	return size;
140
}
141

142
static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
143
{
144
	return xdl_recs_copy_0(0, xe, i, count, needs_cr, add_nl, dest);
145
}
146

147
static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
148
{
149
	return xdl_recs_copy_0(1, xe, i, count, needs_cr, add_nl, dest);
150
}
151

152
/*
153
 * Returns 1 if the i'th line ends in CR/LF (if it is the last line and
154
 * has no eol, the preceding line, if any), 0 if it ends in LF-only, and
155
 * -1 if the line ending cannot be determined.
156
 */
157
static int is_eol_crlf(xdfile_t *file, int i)
158
{
159
	long size;
160

161
	if (i < file->nrec - 1)
162
		/* All lines before the last *must* end in LF */
163
		return (size = file->recs[i]->size) > 1 &&
164
			file->recs[i]->ptr[size - 2] == '\r';
165
	if (!file->nrec)
166
		/* Cannot determine eol style from empty file */
167
		return -1;
168
	if ((size = file->recs[i]->size) &&
169
			file->recs[i]->ptr[size - 1] == '\n')
170
		/* Last line; ends in LF; Is it CR/LF? */
171
		return size > 1 &&
172
			file->recs[i]->ptr[size - 2] == '\r';
173
	if (!i)
174
		/* The only line has no eol */
175
		return -1;
176
	/* Determine eol from second-to-last line */
177
	return (size = file->recs[i - 1]->size) > 1 &&
178
		file->recs[i - 1]->ptr[size - 2] == '\r';
179
}
180

181
static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
182
{
183
	int needs_cr;
184

185
	/* Match post-images' preceding, or first, lines' end-of-line style */
186
	needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
187
	if (needs_cr)
188
		needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
189
	/* Look at pre-image's first line, unless we already settled on LF */
190
	if (needs_cr)
191
		needs_cr = is_eol_crlf(&xe1->xdf1, 0);
192
	/* If still undecided, use LF-only */
193
	return needs_cr < 0 ? 0 : needs_cr;
194
}
195

196
static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
197
			      xdfenv_t *xe2, const char *name2,
198
			      const char *name3,
199
			      int size, int i, int style,
200
			      xdmerge_t *m, char *dest, int marker_size)
201
{
202
	int marker1_size = (name1 ? strlen(name1) + 1 : 0);
203
	int marker2_size = (name2 ? strlen(name2) + 1 : 0);
204
	int marker3_size = (name3 ? strlen(name3) + 1 : 0);
205
	int needs_cr = is_cr_needed(xe1, xe2, m);
206

207
	if (marker_size <= 0)
208
		marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
209

210
	/* Before conflicting part */
211
	size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
212
			      dest ? dest + size : NULL);
213

214
	if (!dest) {
215
		size += marker_size + 1 + needs_cr + marker1_size;
216
	} else {
217
		memset(dest + size, '<', marker_size);
218
		size += marker_size;
219
		if (marker1_size) {
220
			dest[size] = ' ';
221
			memcpy(dest + size + 1, name1, marker1_size - 1);
222
			size += marker1_size;
223
		}
224
		if (needs_cr)
225
			dest[size++] = '\r';
226
		dest[size++] = '\n';
227
	}
228

229
	/* Postimage from side #1 */
230
	size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, 1,
231
			      dest ? dest + size : NULL);
232

233
	if (style == XDL_MERGE_DIFF3 || style == XDL_MERGE_ZEALOUS_DIFF3) {
234
		/* Shared preimage */
235
		if (!dest) {
236
			size += marker_size + 1 + needs_cr + marker3_size;
237
		} else {
238
			memset(dest + size, '|', marker_size);
239
			size += marker_size;
240
			if (marker3_size) {
241
				dest[size] = ' ';
242
				memcpy(dest + size + 1, name3, marker3_size - 1);
243
				size += marker3_size;
244
			}
245
			if (needs_cr)
246
				dest[size++] = '\r';
247
			dest[size++] = '\n';
248
		}
249
		size += xdl_orig_copy(xe1, m->i0, m->chg0, needs_cr, 1,
250
				      dest ? dest + size : NULL);
251
	}
252

253
	if (!dest) {
254
		size += marker_size + 1 + needs_cr;
255
	} else {
256
		memset(dest + size, '=', marker_size);
257
		size += marker_size;
258
		if (needs_cr)
259
			dest[size++] = '\r';
260
		dest[size++] = '\n';
261
	}
262

263
	/* Postimage from side #2 */
264
	size += xdl_recs_copy(xe2, m->i2, m->chg2, needs_cr, 1,
265
			      dest ? dest + size : NULL);
266
	if (!dest) {
267
		size += marker_size + 1 + needs_cr + marker2_size;
268
	} else {
269
		memset(dest + size, '>', marker_size);
270
		size += marker_size;
271
		if (marker2_size) {
272
			dest[size] = ' ';
273
			memcpy(dest + size + 1, name2, marker2_size - 1);
274
			size += marker2_size;
275
		}
276
		if (needs_cr)
277
			dest[size++] = '\r';
278
		dest[size++] = '\n';
279
	}
280
	return size;
281
}
282

283
static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
284
				 xdfenv_t *xe2, const char *name2,
285
				 const char *ancestor_name,
286
				 int favor,
287
				 xdmerge_t *m, char *dest, int style,
288
				 int marker_size)
289
{
290
	int size, i;
291

292
	for (size = i = 0; m; m = m->next) {
293
		if (favor && !m->mode)
294
			m->mode = favor;
295

296
		if (m->mode == 0)
297
			size = fill_conflict_hunk(xe1, name1, xe2, name2,
298
						  ancestor_name,
299
						  size, i, style, m, dest,
300
						  marker_size);
301
		else if (m->mode & 3) {
302
			/* Before conflicting part */
303
			size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
304
					      dest ? dest + size : NULL);
305
			/* Postimage from side #1 */
306
			if (m->mode & 1) {
307
				int needs_cr = is_cr_needed(xe1, xe2, m);
308

309
				size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, (m->mode & 2),
310
						      dest ? dest + size : NULL);
311
			}
312
			/* Postimage from side #2 */
313
			if (m->mode & 2)
314
				size += xdl_recs_copy(xe2, m->i2, m->chg2, 0, 0,
315
						      dest ? dest + size : NULL);
316
		} else
317
			continue;
318
		i = m->i1 + m->chg1;
319
	}
320
	size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 0, 0,
321
			      dest ? dest + size : NULL);
322
	return size;
323
}
324

325
static int recmatch(xrecord_t *rec1, xrecord_t *rec2, unsigned long flags)
326
{
327
	return xdl_recmatch(rec1->ptr, rec1->size,
328
			    rec2->ptr, rec2->size, flags);
329
}
330

331
/*
332
 * Remove any common lines from the beginning and end of the conflicted region.
333
 */
334
static void xdl_refine_zdiff3_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
335
		xpparam_t const *xpp)
336
{
337
	xrecord_t **rec1 = xe1->xdf2.recs, **rec2 = xe2->xdf2.recs;
338
	for (; m; m = m->next) {
339
		/* let's handle just the conflicts */
340
		if (m->mode)
341
			continue;
342

343
		while(m->chg1 && m->chg2 &&
344
		      recmatch(rec1[m->i1], rec2[m->i2], xpp->flags)) {
345
			m->chg1--;
346
			m->chg2--;
347
			m->i1++;
348
			m->i2++;
349
		}
350
		while (m->chg1 && m->chg2 &&
351
		       recmatch(rec1[m->i1 + m->chg1 - 1],
352
				rec2[m->i2 + m->chg2 - 1], xpp->flags)) {
353
			m->chg1--;
354
			m->chg2--;
355
		}
356
	}
357
}
358

359
/*
360
 * Sometimes, changes are not quite identical, but differ in only a few
361
 * lines. Try hard to show only these few lines as conflicting.
362
 */
363
static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
364
		xpparam_t const *xpp)
365
{
366
	for (; m; m = m->next) {
367
		mmfile_t t1, t2;
368
		xdfenv_t xe;
369
		xdchange_t *xscr, *x;
370
		int i1 = m->i1, i2 = m->i2;
371

372
		/* let's handle just the conflicts */
373
		if (m->mode)
374
			continue;
375

376
		/* no sense refining a conflict when one side is empty */
377
		if (m->chg1 == 0 || m->chg2 == 0)
378
			continue;
379

380
		/*
381
		 * This probably does not work outside git, since
382
		 * we have a very simple mmfile structure.
383
		 */
384
		t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
385
		t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
386
			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
387
		t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
388
		t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
389
			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
390
		if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
391
			return -1;
392
		if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
393
		    xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
394
		    xdl_build_script(&xe, &xscr) < 0) {
395
			xdl_free_env(&xe);
396
			return -1;
397
		}
398
		if (!xscr) {
399
			/* If this happens, the changes are identical. */
400
			xdl_free_env(&xe);
401
			m->mode = 4;
402
			continue;
403
		}
404
		x = xscr;
405
		m->i1 = xscr->i1 + i1;
406
		m->chg1 = xscr->chg1;
407
		m->i2 = xscr->i2 + i2;
408
		m->chg2 = xscr->chg2;
409
		while (xscr->next) {
410
			xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
411
			if (!m2) {
412
				xdl_free_env(&xe);
413
				xdl_free_script(x);
414
				return -1;
415
			}
416
			xscr = xscr->next;
417
			m2->next = m->next;
418
			m->next = m2;
419
			m = m2;
420
			m->mode = 0;
421
			m->i1 = xscr->i1 + i1;
422
			m->chg1 = xscr->chg1;
423
			m->i2 = xscr->i2 + i2;
424
			m->chg2 = xscr->chg2;
425
		}
426
		xdl_free_env(&xe);
427
		xdl_free_script(x);
428
	}
429
	return 0;
430
}
431

432
static int line_contains_alnum(const char *ptr, long size)
433
{
434
	while (size--)
435
		if (isalnum((unsigned char)*(ptr++)))
436
			return 1;
437
	return 0;
438
}
439

440
static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
441
{
442
	for (; chg; chg--, i++)
443
		if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
444
				xe->xdf2.recs[i]->size))
445
			return 1;
446
	return 0;
447
}
448

449
/*
450
 * This function merges m and m->next, marking everything between those hunks
451
 * as conflicting, too.
452
 */
453
static void xdl_merge_two_conflicts(xdmerge_t *m)
454
{
455
	xdmerge_t *next_m = m->next;
456
	m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
457
	m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
458
	m->next = next_m->next;
459
	free(next_m);
460
}
461

462
/*
463
 * If there are less than 3 non-conflicting lines between conflicts,
464
 * it appears simpler -- because it takes up less (or as many) lines --
465
 * if the lines are moved into the conflicts.
466
 */
467
static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
468
				      int simplify_if_no_alnum)
469
{
470
	int result = 0;
471

472
	if (!m)
473
		return result;
474
	for (;;) {
475
		xdmerge_t *next_m = m->next;
476
		int begin, end;
477

478
		if (!next_m)
479
			return result;
480

481
		begin = m->i1 + m->chg1;
482
		end = next_m->i1;
483

484
		if (m->mode != 0 || next_m->mode != 0 ||
485
		    (end - begin > 3 &&
486
		     (!simplify_if_no_alnum ||
487
		      lines_contain_alnum(xe1, begin, end - begin)))) {
488
			m = next_m;
489
		} else {
490
			result++;
491
			xdl_merge_two_conflicts(m);
492
		}
493
	}
494
}
495

496
/*
497
 * level == 0: mark all overlapping changes as conflict
498
 * level == 1: mark overlapping changes as conflict only if not identical
499
 * level == 2: analyze non-identical changes for minimal conflict set
500
 * level == 3: analyze non-identical changes for minimal conflict set, but
501
 *             treat hunks not containing any letter or number as conflicting
502
 *
503
 * returns < 0 on error, == 0 for no conflicts, else number of conflicts
504
 */
505
static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1,
506
		xdfenv_t *xe2, xdchange_t *xscr2,
507
		xmparam_t const *xmp, mmbuffer_t *result)
508
{
509
	xdmerge_t *changes, *c;
510
	xpparam_t const *xpp = &xmp->xpp;
511
	const char *const ancestor_name = xmp->ancestor;
512
	const char *const name1 = xmp->file1;
513
	const char *const name2 = xmp->file2;
514
	int i0, i1, i2, chg0, chg1, chg2;
515
	int level = xmp->level;
516
	int style = xmp->style;
517
	int favor = xmp->favor;
518

519
	/*
520
	 * XDL_MERGE_DIFF3 does not attempt to refine conflicts by looking
521
	 * at common areas of sides 1 & 2, because the base (side 0) does
522
	 * not match and is being shown.  Similarly, simplification of
523
	 * non-conflicts is also skipped due to the skipping of conflict
524
	 * refinement.
525
	 *
526
	 * XDL_MERGE_ZEALOUS_DIFF3, on the other hand, will attempt to
527
	 * refine conflicts looking for common areas of sides 1 & 2.
528
	 * However, since the base is being shown and does not match,
529
	 * it will only look for common areas at the beginning or end
530
	 * of the conflict block.  Since XDL_MERGE_ZEALOUS_DIFF3's
531
	 * conflict refinement is much more limited in this fashion, the
532
	 * conflict simplification will be skipped.
533
	 */
534
	if (style == XDL_MERGE_DIFF3 || style == XDL_MERGE_ZEALOUS_DIFF3) {
535
		/*
536
		 * "diff3 -m" output does not make sense for anything
537
		 * more aggressive than XDL_MERGE_EAGER.
538
		 */
539
		if (XDL_MERGE_EAGER < level)
540
			level = XDL_MERGE_EAGER;
541
	}
542

543
	c = changes = NULL;
544

545
	while (xscr1 && xscr2) {
546
		if (!changes)
547
			changes = c;
548
		if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
549
			i0 = xscr1->i1;
550
			i1 = xscr1->i2;
551
			i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
552
			chg0 = xscr1->chg1;
553
			chg1 = xscr1->chg2;
554
			chg2 = xscr1->chg1;
555
			if (xdl_append_merge(&c, 1,
556
					     i0, chg0, i1, chg1, i2, chg2)) {
557
				xdl_cleanup_merge(changes);
558
				return -1;
559
			}
560
			xscr1 = xscr1->next;
561
			continue;
562
		}
563
		if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
564
			i0 = xscr2->i1;
565
			i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
566
			i2 = xscr2->i2;
567
			chg0 = xscr2->chg1;
568
			chg1 = xscr2->chg1;
569
			chg2 = xscr2->chg2;
570
			if (xdl_append_merge(&c, 2,
571
					     i0, chg0, i1, chg1, i2, chg2)) {
572
				xdl_cleanup_merge(changes);
573
				return -1;
574
			}
575
			xscr2 = xscr2->next;
576
			continue;
577
		}
578
		if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
579
				xscr1->chg1 != xscr2->chg1 ||
580
				xscr1->chg2 != xscr2->chg2 ||
581
				xdl_merge_cmp_lines(xe1, xscr1->i2,
582
					xe2, xscr2->i2,
583
					xscr1->chg2, xpp->flags)) {
584
			/* conflict */
585
			int off = xscr1->i1 - xscr2->i1;
586
			int ffo = off + xscr1->chg1 - xscr2->chg1;
587

588
			i0 = xscr1->i1;
589
			i1 = xscr1->i2;
590
			i2 = xscr2->i2;
591
			if (off > 0) {
592
				i0 -= off;
593
				i1 -= off;
594
			}
595
			else
596
				i2 += off;
597
			chg0 = xscr1->i1 + xscr1->chg1 - i0;
598
			chg1 = xscr1->i2 + xscr1->chg2 - i1;
599
			chg2 = xscr2->i2 + xscr2->chg2 - i2;
600
			if (ffo < 0) {
601
				chg0 -= ffo;
602
				chg1 -= ffo;
603
			} else
604
				chg2 += ffo;
605
			if (xdl_append_merge(&c, 0,
606
					     i0, chg0, i1, chg1, i2, chg2)) {
607
				xdl_cleanup_merge(changes);
608
				return -1;
609
			}
610
		}
611

612
		i1 = xscr1->i1 + xscr1->chg1;
613
		i2 = xscr2->i1 + xscr2->chg1;
614

615
		if (i1 >= i2)
616
			xscr2 = xscr2->next;
617
		if (i2 >= i1)
618
			xscr1 = xscr1->next;
619
	}
620
	while (xscr1) {
621
		if (!changes)
622
			changes = c;
623
		i0 = xscr1->i1;
624
		i1 = xscr1->i2;
625
		i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
626
		chg0 = xscr1->chg1;
627
		chg1 = xscr1->chg2;
628
		chg2 = xscr1->chg1;
629
		if (xdl_append_merge(&c, 1,
630
				     i0, chg0, i1, chg1, i2, chg2)) {
631
			xdl_cleanup_merge(changes);
632
			return -1;
633
		}
634
		xscr1 = xscr1->next;
635
	}
636
	while (xscr2) {
637
		if (!changes)
638
			changes = c;
639
		i0 = xscr2->i1;
640
		i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
641
		i2 = xscr2->i2;
642
		chg0 = xscr2->chg1;
643
		chg1 = xscr2->chg1;
644
		chg2 = xscr2->chg2;
645
		if (xdl_append_merge(&c, 2,
646
				     i0, chg0, i1, chg1, i2, chg2)) {
647
			xdl_cleanup_merge(changes);
648
			return -1;
649
		}
650
		xscr2 = xscr2->next;
651
	}
652
	if (!changes)
653
		changes = c;
654
	/* refine conflicts */
655
	if (style == XDL_MERGE_ZEALOUS_DIFF3) {
656
		xdl_refine_zdiff3_conflicts(xe1, xe2, changes, xpp);
657
	} else if (XDL_MERGE_ZEALOUS <= level &&
658
		   (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
659
		    xdl_simplify_non_conflicts(xe1, changes,
660
					       XDL_MERGE_ZEALOUS < level) < 0)) {
661
		xdl_cleanup_merge(changes);
662
		return -1;
663
	}
664
	/* output */
665
	if (result) {
666
		int marker_size = xmp->marker_size;
667
		int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
668
						 ancestor_name,
669
						 favor, changes, NULL, style,
670
						 marker_size);
671
		result->ptr = xdl_malloc(size);
672
		if (!result->ptr) {
673
			xdl_cleanup_merge(changes);
674
			return -1;
675
		}
676
		result->size = size;
677
		xdl_fill_merge_buffer(xe1, name1, xe2, name2,
678
				      ancestor_name, favor, changes,
679
				      result->ptr, style, marker_size);
680
	}
681
	return xdl_cleanup_merge(changes);
682
}
683

684
int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
685
		xmparam_t const *xmp, mmbuffer_t *result)
686
{
687
	xdchange_t *xscr1 = NULL, *xscr2 = NULL;
688
	xdfenv_t xe1, xe2;
689
	int status = -1;
690
	xpparam_t const *xpp = &xmp->xpp;
691

692
	result->ptr = NULL;
693
	result->size = 0;
694

695
	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0)
696
		return -1;
697

698
	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0)
699
		goto free_xe1; /* avoid double free of xe2 */
700

701
	if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
702
	    xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
703
	    xdl_build_script(&xe1, &xscr1) < 0)
704
		goto out;
705

706
	if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
707
	    xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
708
	    xdl_build_script(&xe2, &xscr2) < 0)
709
		goto out;
710

711
	if (!xscr1) {
712
		result->ptr = xdl_malloc(mf2->size);
713
		if (!result->ptr)
714
			goto out;
715
		status = 0;
716
		memcpy(result->ptr, mf2->ptr, mf2->size);
717
		result->size = mf2->size;
718
	} else if (!xscr2) {
719
		result->ptr = xdl_malloc(mf1->size);
720
		if (!result->ptr)
721
			goto out;
722
		status = 0;
723
		memcpy(result->ptr, mf1->ptr, mf1->size);
724
		result->size = mf1->size;
725
	} else {
726
		status = xdl_do_merge(&xe1, xscr1,
727
				      &xe2, xscr2,
728
				      xmp, result);
729
	}
730
 out:
731
	xdl_free_script(xscr1);
732
	xdl_free_script(xscr2);
733

734
	xdl_free_env(&xe2);
735
 free_xe1:
736
	xdl_free_env(&xe1);
737

738
	return status;
739
}
740