1 /*
2  * Copyright (c) 2017 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/stat.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <limits.h>
24 #include <zlib.h>
25 
26 #include "got_compat.h"
27 
28 #include "got_object.h"
29 #include "got_repository.h"
30 #include "got_error.h"
31 #include "got_diff.h"
32 #include "got_path.h"
33 #include "got_cancel.h"
34 #include "got_worktree.h"
35 #include "got_opentemp.h"
36 
37 #include "got_lib_diff.h"
38 #include "got_lib_delta.h"
39 #include "got_lib_inflate.h"
40 #include "got_lib_object.h"
41 
42 #ifndef MAX
43 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
44 #endif
45 
46 static const struct got_error *
47 add_line_metadata(struct got_diff_line **lines, size_t *nlines,
48     off_t off, uint8_t type)
49 {
50 	struct got_diff_line *p;
51 
52 	p = reallocarray(*lines, *nlines + 1, sizeof(**lines));
53 	if (p == NULL)
54 		return got_error_from_errno("reallocarray");
55 	*lines = p;
56 	(*lines)[*nlines].offset = off;
57 	(*lines)[*nlines].type = type;
58 	(*nlines)++;
59 
60 	return NULL;
61 }
62 
63 static void
64 diffstat_field_width(size_t *maxlen, int *add_cols, int *rm_cols, size_t len,
65     uint32_t add, uint32_t rm)
66 {
67 	int d1 = 1, d2 = 1;
68 
69 	if (maxlen)
70 		*maxlen = MAX(*maxlen, len);
71 
72 	while (add /= 10)
73 		++d1;
74 	*add_cols = MAX(*add_cols, d1);
75 
76 	while (rm /= 10)
77 		++d2;
78 	*rm_cols = MAX(*rm_cols, d2);
79 }
80 
81 static const struct got_error *
82 get_diffstat(struct got_diffstat_cb_arg *ds, const char *path,
83     struct diff_result *r, int force_text, int status)
84 {
85 	const struct got_error *err;
86 	struct got_pathlist_entry *pe;
87 	struct got_diff_changed_path *change = NULL;
88 	int flags = (r->left->atomizer_flags | r->right->atomizer_flags);
89 	int isbin = (flags & DIFF_ATOMIZER_FOUND_BINARY_DATA);
90 	int i;
91 
92 	change = calloc(1, sizeof(*change));
93 	if (change == NULL)
94 		return got_error_from_errno("calloc");
95 
96 	if (!isbin || force_text) {
97 		for (i = 0; i < r->chunks.len; ++i) {
98 			struct diff_chunk *c;
99 			int clc, crc;
100 
101 			c = diff_chunk_get(r, i);
102 			clc = diff_chunk_get_left_count(c);
103 			crc = diff_chunk_get_right_count(c);
104 
105 			if (crc && !clc)
106 				change->add += crc;
107 			if (clc && !crc)
108 				change->rm += clc;
109 		}
110 	}
111 
112 	change->status = status;
113 	ds->ins += change->add;
114 	ds->del += change->rm;
115 	++ds->nfiles;
116 
117 	err = got_pathlist_append(ds->paths, path, change);
118 	if (err) {
119 		free(change);
120 		return err;
121 	}
122 
123 	pe = TAILQ_LAST(ds->paths, got_pathlist_head);
124 	diffstat_field_width(&ds->max_path_len, &ds->add_cols, &ds->rm_cols,
125 	    pe->path_len, change->add, change->rm);
126 
127 	return NULL;
128 }
129 
130 static const struct got_error *
131 diff_blobs(struct got_diff_line **lines, size_t *nlines,
132     struct got_diffreg_result **resultp, struct got_blob_object *blob1,
133     struct got_blob_object *blob2, FILE *f1, FILE *f2,
134     const char *label1, const char *label2, mode_t mode1, mode_t mode2,
135     int diff_context, int ignore_whitespace, int force_text_diff,
136     int show_diffstat, struct got_diffstat_cb_arg *ds, FILE *outfile,
137     enum got_diff_algorithm diff_algo)
138 {
139 	const struct got_error *err = NULL, *free_err;
140 	char hex1[SHA1_DIGEST_STRING_LENGTH];
141 	char hex2[SHA1_DIGEST_STRING_LENGTH];
142 	const char *idstr1 = NULL, *idstr2 = NULL;
143 	char *modestr1 = NULL, *modestr2 = NULL;
144 	off_t size1, size2;
145 	struct got_diffreg_result *result = NULL;
146 	off_t outoff = 0;
147 	int n;
148 
149 	if (lines && *lines && *nlines > 0)
150 		outoff = (*lines)[*nlines - 1].offset;
151 	else if (lines) {
152 		err = add_line_metadata(lines, nlines, 0, GOT_DIFF_LINE_NONE);
153 		if (err)
154 			goto done;
155 	}
156 
157 	if (resultp)
158 		*resultp = NULL;
159 
160 	if (f1) {
161 		err = got_opentemp_truncate(f1);
162 		if (err)
163 			goto done;
164 	}
165 	if (f2) {
166 		err = got_opentemp_truncate(f2);
167 		if (err)
168 			goto done;
169 	}
170 
171 	size1 = 0;
172 	if (blob1) {
173 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
174 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
175 		    blob1);
176 		if (err)
177 			goto done;
178 	} else
179 		idstr1 = "/dev/null";
180 
181 	size2 = 0;
182 	if (blob2) {
183 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
184 		err = got_object_blob_dump_to_file(&size2, NULL, NULL, f2,
185 		    blob2);
186 		if (err)
187 			goto done;
188 	} else
189 		idstr2 = "/dev/null";
190 
191 	if (outfile) {
192 		int modebits;
193 
194 		if (mode1 && mode1 != mode2) {
195 			if (S_ISLNK(mode1))
196 				modebits = S_IFLNK;
197 			else
198 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
199 			if (asprintf(&modestr1, " (mode %o)",
200 			    mode1 & modebits) == -1) {
201 				err = got_error_from_errno("asprintf");
202 				goto done;
203 			}
204 		}
205 		if (mode2 && mode1 != mode2) {
206 			if (S_ISLNK(mode2))
207 				modebits = S_IFLNK;
208 			else
209 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
210 			if (asprintf(&modestr2, " (mode %o)",
211 			    mode2 & modebits) == -1) {
212 				err = got_error_from_errno("asprintf");
213 				goto done;
214 			}
215 		}
216 		n = fprintf(outfile, "blob - %s%s\n", idstr1,
217 		    modestr1 ? modestr1 : "");
218 		if (n < 0)
219 			goto done;
220 		outoff += n;
221 		if (lines) {
222 			err = add_line_metadata(lines, nlines, outoff,
223 			    GOT_DIFF_LINE_BLOB_MIN);
224 			if (err)
225 				goto done;
226 		}
227 
228 		n = fprintf(outfile, "blob + %s%s\n", idstr2,
229 		    modestr2 ? modestr2 : "");
230 		if (n < 0)
231 			goto done;
232 		outoff += n;
233 		if (lines) {
234 			err = add_line_metadata(lines, nlines, outoff,
235 			    GOT_DIFF_LINE_BLOB_PLUS);
236 			if (err)
237 				goto done;
238 		}
239 	}
240 
241 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
242 	     force_text_diff);
243 	if (err)
244 		goto done;
245 
246 	if (show_diffstat) {
247 		char	*path = NULL;
248 		int	 status = GOT_STATUS_NO_CHANGE;
249 
250 		/*
251 		 * Ignore 'm'ode status change: if there's no accompanying
252 		 * content change, there'll be no diffstat, and if there
253 		 * are actual changes, 'M'odified takes precedence.
254 		 */
255 		if (blob1 == NULL)
256 			status = GOT_STATUS_ADD;
257 		else if (blob2 == NULL)
258 			status = GOT_STATUS_DELETE;
259 		else
260 			status = GOT_STATUS_MODIFY;
261 
262 		if (label1 == NULL && label2 == NULL) {
263 			/* diffstat of blobs, show hash instead of path */
264 			if (asprintf(&path, "%.10s -> %.10s",
265 			    idstr1, idstr2) == -1) {
266 				err = got_error_from_errno("asprintf");
267 				goto done;
268 			}
269 		} else {
270 			if (label2 != NULL &&
271 			    (status != GOT_STATUS_DELETE || label1 == NULL))
272 				path = strdup(label2);
273 			else
274 				path = strdup(label1);
275 			if (path == NULL) {
276 				err = got_error_from_errno("strdup");
277 				goto done;
278 			}
279 		}
280 
281 		err = get_diffstat(ds, path, result->result, force_text_diff,
282 		    status);
283 		if (err) {
284 			free(path);
285 			goto done;
286 		}
287 	}
288 
289 	if (outfile) {
290 		err = got_diffreg_output(lines, nlines, result,
291 		    blob1 != NULL, blob2 != NULL,
292 		    label1 ? label1 : idstr1,
293 		    label2 ? label2 : idstr2,
294 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
295 		if (err)
296 			goto done;
297 	}
298 
299 done:
300 	free(modestr1);
301 	free(modestr2);
302 	if (resultp && err == NULL)
303 		*resultp = result;
304 	else if (result) {
305 		free_err = got_diffreg_result_free(result);
306 		if (free_err && err == NULL)
307 			err = free_err;
308 	}
309 
310 	return err;
311 }
312 
313 const struct got_error *
314 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
315     struct got_blob_object *blob2, FILE *f1, FILE *f2,
316     struct got_object_id *id1, struct got_object_id *id2,
317     const char *label1, const char *label2, mode_t mode1, mode_t mode2,
318     struct got_repository *repo)
319 {
320 	struct got_diff_blob_output_unidiff_arg *a = arg;
321 
322 	return diff_blobs(&a->lines, &a->nlines, NULL,
323 	    blob1, blob2, f1, f2, label1, label2, mode1, mode2, a->diff_context,
324 	    a->ignore_whitespace, a->force_text_diff, a->show_diffstat,
325 	    a->diffstat, a->outfile, a->diff_algo);
326 }
327 
328 const struct got_error *
329 got_diff_blob(struct got_diff_line **lines, size_t*nlines,
330     struct got_blob_object *blob1, struct got_blob_object *blob2,
331     FILE *f1, FILE *f2, const char *label1, const char *label2,
332     enum got_diff_algorithm diff_algo, int diff_context,
333     int ignore_whitespace, int force_text_diff, int show_diffstat,
334     struct got_diffstat_cb_arg *ds, FILE *outfile)
335 {
336 	return diff_blobs(lines, nlines, NULL, blob1, blob2, f1, f2,
337 	    label1, label2, 0, 0, diff_context, ignore_whitespace,
338 	    force_text_diff, show_diffstat, ds, outfile, diff_algo);
339 }
340 
341 static const struct got_error *
342 diff_blob_file(struct got_diffreg_result **resultp,
343     struct got_blob_object *blob1, FILE *f1, off_t size1, const char *label1,
344     FILE *f2, int f2_exists, struct stat *sb2, const char *label2,
345     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
346     int force_text_diff, int show_diffstat, struct got_diffstat_cb_arg *ds,
347     FILE *outfile)
348 {
349 	const struct got_error *err = NULL, *free_err;
350 	char hex1[SHA1_DIGEST_STRING_LENGTH];
351 	const char *idstr1 = NULL;
352 	struct got_diffreg_result *result = NULL;
353 
354 	if (resultp)
355 		*resultp = NULL;
356 
357 	if (blob1)
358 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
359 	else
360 		idstr1 = "/dev/null";
361 
362 	if (outfile) {
363 		char	*mode = NULL;
364 
365 		/* display file mode for new added files only */
366 		if (f2_exists && blob1 == NULL) {
367 			int mmask = (S_IRWXU | S_IRWXG | S_IRWXO);
368 
369 			if (S_ISLNK(sb2->st_mode))
370 				mmask = S_IFLNK;
371 			if (asprintf(&mode, " (mode %o)",
372 			    sb2->st_mode & mmask) == -1)
373 				return got_error_from_errno("asprintf");
374 		}
375 		fprintf(outfile, "blob - %s\n", label1 ? label1 : idstr1);
376 		fprintf(outfile, "file + %s%s\n",
377 		    f2_exists ? label2 : "/dev/null", mode ? mode : "");
378 		free(mode);
379 	}
380 
381 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
382 	    force_text_diff);
383 	if (err)
384 		goto done;
385 
386 	if (outfile) {
387 		err = got_diffreg_output(NULL, NULL, result,
388 		    blob1 != NULL, f2_exists,
389 		    label2, /* show local file's path, not a blob ID */
390 		    label2, GOT_DIFF_OUTPUT_UNIDIFF,
391 		    diff_context, outfile);
392 		if (err)
393 			goto done;
394 	}
395 
396 	if (show_diffstat) {
397 		char	*path = NULL;
398 		int	 status = GOT_STATUS_NO_CHANGE;
399 
400 		/*
401 		 * Ignore 'm'ode status change: if there's no accompanying
402 		 * content change, there'll be no diffstat, and if there
403 		 * are actual changes, 'M'odified takes precedence.
404 		 */
405 		if (blob1 == NULL)
406 			status = GOT_STATUS_ADD;
407 		else if (!f2_exists)
408 			status = GOT_STATUS_DELETE;
409 		else
410 			status = GOT_STATUS_MODIFY;
411 
412 		if (label2 != NULL &&
413 		    (status != GOT_STATUS_DELETE || label1 == NULL))
414 			path = strdup(label2);
415 		else
416 			path = strdup(label1);
417 		if (path == NULL) {
418 			err = got_error_from_errno("strdup");
419 			goto done;
420 		}
421 
422 		err = get_diffstat(ds, path, result->result, force_text_diff,
423 		    status);
424 		if (err) {
425 			free(path);
426 			goto done;
427 		}
428 	}
429 
430 done:
431 	if (resultp && err == NULL)
432 		*resultp = result;
433 	else if (result) {
434 		free_err = got_diffreg_result_free(result);
435 		if (free_err && err == NULL)
436 			err = free_err;
437 	}
438 	return err;
439 }
440 
441 const struct got_error *
442 got_diff_blob_file(struct got_blob_object *blob1, FILE *f1, off_t size1,
443     const char *label1, FILE *f2, int f2_exists, struct stat *sb2,
444     const char *label2, enum got_diff_algorithm diff_algo, int diff_context,
445     int ignore_whitespace, int force_text_diff, int show_diffstat,
446     struct got_diffstat_cb_arg *ds, FILE *outfile)
447 {
448 	return diff_blob_file(NULL, blob1, f1, size1, label1, f2, f2_exists,
449 	    sb2, label2, diff_algo, diff_context, ignore_whitespace,
450 	    force_text_diff, show_diffstat, ds, outfile);
451 }
452 
453 static const struct got_error *
454 diff_added_blob(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
455     const char *label, mode_t mode, struct got_repository *repo,
456     got_diff_blob_cb cb, void *cb_arg)
457 {
458 	const struct got_error *err;
459 	struct got_blob_object  *blob = NULL;
460 	struct got_object *obj = NULL;
461 
462 	err = got_object_open(&obj, repo, id);
463 	if (err)
464 		return err;
465 
466 	err = got_object_blob_open(&blob, repo, obj, 8192, fd2);
467 	if (err)
468 		goto done;
469 	err = cb(cb_arg, NULL, blob, f1, f2, NULL, id,
470 	    NULL, label, 0, mode, repo);
471 done:
472 	got_object_close(obj);
473 	if (blob)
474 		got_object_blob_close(blob);
475 	return err;
476 }
477 
478 static const struct got_error *
479 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
480     FILE *f1, FILE *f2, int fd1, int fd2,
481     const char *label1, const char *label2,
482     mode_t mode1, mode_t mode2, struct got_repository *repo,
483     got_diff_blob_cb cb, void *cb_arg)
484 {
485 	const struct got_error *err;
486 	struct got_object *obj1 = NULL;
487 	struct got_object *obj2 = NULL;
488 	struct got_blob_object *blob1 = NULL;
489 	struct got_blob_object *blob2 = NULL;
490 
491 	err = got_object_open(&obj1, repo, id1);
492 	if (err)
493 		return err;
494 
495 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
496 		err = got_error(GOT_ERR_OBJ_TYPE);
497 		goto done;
498 	}
499 
500 	err = got_object_open(&obj2, repo, id2);
501 	if (err)
502 		goto done;
503 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
504 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
505 		goto done;
506 	}
507 
508 	err = got_object_blob_open(&blob1, repo, obj1, 8192, fd1);
509 	if (err)
510 		goto done;
511 
512 	err = got_object_blob_open(&blob2, repo, obj2, 8192, fd2);
513 	if (err)
514 		goto done;
515 
516 	err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2, label1, label2,
517 	    mode1, mode2, repo);
518 done:
519 	if (obj1)
520 		got_object_close(obj1);
521 	if (obj2)
522 		got_object_close(obj2);
523 	if (blob1)
524 		got_object_blob_close(blob1);
525 	if (blob2)
526 		got_object_blob_close(blob2);
527 	return err;
528 }
529 
530 static const struct got_error *
531 diff_deleted_blob(struct got_object_id *id, FILE *f1, int fd1,
532    FILE *f2, const char *label, mode_t mode, struct got_repository *repo,
533    got_diff_blob_cb cb, void *cb_arg)
534 {
535 	const struct got_error *err;
536 	struct got_blob_object  *blob = NULL;
537 	struct got_object *obj = NULL;
538 
539 	err = got_object_open(&obj, repo, id);
540 	if (err)
541 		return err;
542 
543 	err = got_object_blob_open(&blob, repo, obj, 8192, fd1);
544 	if (err)
545 		goto done;
546 	err = cb(cb_arg, blob, NULL, f1, f2, id, NULL, label, NULL,
547 	    mode, 0, repo);
548 done:
549 	got_object_close(obj);
550 	if (blob)
551 		got_object_blob_close(blob);
552 	return err;
553 }
554 
555 static const struct got_error *
556 diff_added_tree(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
557     const char *label, struct got_repository *repo, got_diff_blob_cb cb,
558     void *cb_arg, int diff_content)
559 {
560 	const struct got_error *err = NULL;
561 	struct got_object *treeobj = NULL;
562 	struct got_tree_object *tree = NULL;
563 
564 	err = got_object_open(&treeobj, repo, id);
565 	if (err)
566 		goto done;
567 
568 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
569 		err = got_error(GOT_ERR_OBJ_TYPE);
570 		goto done;
571 	}
572 
573 	err = got_object_tree_open(&tree, repo, treeobj);
574 	if (err)
575 		goto done;
576 
577 	err = got_diff_tree(NULL, tree, f1, f2, -1, fd2, NULL, label,
578 	    repo, cb, cb_arg, diff_content);
579 done:
580 	if (tree)
581 		got_object_tree_close(tree);
582 	if (treeobj)
583 		got_object_close(treeobj);
584 	return err;
585 }
586 
587 static const struct got_error *
588 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
589     FILE *f1, FILE *f2, int fd1, int fd2,
590     const char *label1, const char *label2,
591     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
592     int diff_content)
593 {
594 	const struct got_error *err;
595 	struct got_object *treeobj1 = NULL;
596 	struct got_object *treeobj2 = NULL;
597 	struct got_tree_object *tree1 = NULL;
598 	struct got_tree_object *tree2 = NULL;
599 
600 	err = got_object_open(&treeobj1, repo, id1);
601 	if (err)
602 		goto done;
603 
604 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
605 		err = got_error(GOT_ERR_OBJ_TYPE);
606 		goto done;
607 	}
608 
609 	err = got_object_open(&treeobj2, repo, id2);
610 	if (err)
611 		goto done;
612 
613 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
614 		err = got_error(GOT_ERR_OBJ_TYPE);
615 		goto done;
616 	}
617 
618 	err = got_object_tree_open(&tree1, repo, treeobj1);
619 	if (err)
620 		goto done;
621 
622 	err = got_object_tree_open(&tree2, repo, treeobj2);
623 	if (err)
624 		goto done;
625 
626 	err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2,
627 	    label1, label2, repo, cb, cb_arg, diff_content);
628 
629 done:
630 	if (tree1)
631 		got_object_tree_close(tree1);
632 	if (tree2)
633 		got_object_tree_close(tree2);
634 	if (treeobj1)
635 		got_object_close(treeobj1);
636 	if (treeobj2)
637 		got_object_close(treeobj2);
638 	return err;
639 }
640 
641 static const struct got_error *
642 diff_deleted_tree(struct got_object_id *id, FILE *f1, int fd1,
643     FILE *f2, const char *label, struct got_repository *repo,
644     got_diff_blob_cb cb, void *cb_arg, int diff_content)
645 {
646 	const struct got_error *err;
647 	struct got_object *treeobj = NULL;
648 	struct got_tree_object *tree = NULL;
649 
650 	err = got_object_open(&treeobj, repo, id);
651 	if (err)
652 		goto done;
653 
654 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
655 		err = got_error(GOT_ERR_OBJ_TYPE);
656 		goto done;
657 	}
658 
659 	err = got_object_tree_open(&tree, repo, treeobj);
660 	if (err)
661 		goto done;
662 
663 	err = got_diff_tree(tree, NULL, f1, f2, fd1, -1, label, NULL,
664 	    repo, cb, cb_arg, diff_content);
665 done:
666 	if (tree)
667 		got_object_tree_close(tree);
668 	if (treeobj)
669 		got_object_close(treeobj);
670 	return err;
671 }
672 
673 static const struct got_error *
674 diff_kind_mismatch(struct got_object_id *id1, struct got_object_id *id2,
675     const char *label1, const char *label2, struct got_repository *repo,
676     got_diff_blob_cb cb, void *cb_arg)
677 {
678 	/* XXX TODO */
679 	return NULL;
680 }
681 
682 static const struct got_error *
683 diff_entry_old_new(struct got_tree_entry *te1, struct got_tree_entry *te2,
684     FILE *f1, FILE *f2, int fd1, int fd2,
685     const char *label1, const char *label2,
686     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
687     int diff_content)
688 {
689 	const struct got_error *err = NULL;
690 	int id_match;
691 
692 	if (got_object_tree_entry_is_submodule(te1))
693 		return NULL;
694 
695 	if (te2 == NULL) {
696 		if (S_ISDIR(te1->mode))
697 			err = diff_deleted_tree(&te1->id, f1, fd1, f2,
698 			    label1, repo, cb, cb_arg, diff_content);
699 		else {
700 			if (diff_content)
701 				err = diff_deleted_blob(&te1->id, f1, fd1,
702 				    f2, label1, te1->mode, repo, cb, cb_arg);
703 			else
704 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
705 				    &te1->id, NULL, label1, NULL,
706 				    te1->mode, 0, repo);
707 		}
708 		return err;
709 	} else if (got_object_tree_entry_is_submodule(te2))
710 		return NULL;
711 
712 	id_match = (got_object_id_cmp(&te1->id, &te2->id) == 0);
713 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
714 		if (!id_match)
715 			return diff_modified_tree(&te1->id, &te2->id, f1, f2,
716 			    fd1, fd2, label1, label2, repo, cb, cb_arg,
717 			    diff_content);
718 	} else if ((S_ISREG(te1->mode) || S_ISLNK(te1->mode)) &&
719 	    (S_ISREG(te2->mode) || S_ISLNK(te2->mode))) {
720 		if (!id_match ||
721 		    ((te1->mode & (S_IFLNK | S_IXUSR))) !=
722 		    (te2->mode & (S_IFLNK | S_IXUSR))) {
723 			if (diff_content)
724 				return diff_modified_blob(&te1->id, &te2->id,
725 				    f1, f2, fd1, fd2, label1, label2,
726 				    te1->mode, te2->mode, repo, cb, cb_arg);
727 			else
728 				return cb(cb_arg, NULL, NULL, NULL, NULL,
729 				    &te1->id, &te2->id, label1, label2,
730 				    te1->mode, te2->mode, repo);
731 		}
732 	}
733 
734 	if (id_match)
735 		return NULL;
736 
737 	return diff_kind_mismatch(&te1->id, &te2->id, label1, label2, repo,
738 	    cb, cb_arg);
739 }
740 
741 static const struct got_error *
742 diff_entry_new_old(struct got_tree_entry *te2,
743     struct got_tree_entry *te1, FILE *f1, FILE *f2, int fd2, const char *label2,
744     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
745     int diff_content)
746 {
747 	if (te1 != NULL) /* handled by diff_entry_old_new() */
748 		return NULL;
749 
750 	if (got_object_tree_entry_is_submodule(te2))
751 		return NULL;
752 
753 	if (S_ISDIR(te2->mode))
754 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
755 		    repo, cb, cb_arg, diff_content);
756 
757 	if (diff_content)
758 		return diff_added_blob(&te2->id, f1, f2, fd2,
759 		    label2, te2->mode, repo, cb, cb_arg);
760 
761 	return cb(cb_arg, NULL, NULL, NULL, NULL, NULL, &te2->id,
762 	    NULL, label2, 0, te2->mode, repo);
763 }
764 
765 const struct got_error *
766 got_diff_tree_compute_diffstat(void *arg, struct got_blob_object *blob1,
767     struct got_blob_object *blob2, FILE *f1, FILE *f2,
768     struct got_object_id *id1, struct got_object_id *id2,
769     const char *label1, const char *label2,
770     mode_t mode1, mode_t mode2, struct got_repository *repo)
771 {
772 	const struct got_error		*err = NULL;
773 	struct got_diffreg_result	*result = NULL;
774 	struct got_diffstat_cb_arg	*a = arg;
775 	char				*path = NULL;
776 	int				 status = GOT_STATUS_NO_CHANGE;
777 
778 	path = strdup(label2 ? label2 : label1);
779 	if (path == NULL)
780 		return got_error_from_errno("strdup");
781 
782 	if (id1 == NULL)
783 		status = GOT_STATUS_ADD;
784 	else if (id2 == NULL)
785 		status = GOT_STATUS_DELETE;
786 	else {
787 		if (got_object_id_cmp(id1, id2) != 0)
788 			status = GOT_STATUS_MODIFY;
789 		else if (mode1 != mode2)
790 			status = GOT_STATUS_MODE_CHANGE;
791 	}
792 
793 	if (f1) {
794 		err = got_opentemp_truncate(f1);
795 		if (err)
796 			goto done;
797 	}
798 	if (f2) {
799 		err = got_opentemp_truncate(f2);
800 		if (err)
801 			goto done;
802 	}
803 
804 	if (blob1) {
805 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1,
806 		    blob1);
807 		if (err)
808 			goto done;
809 	}
810 	if (blob2) {
811 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f2,
812 		    blob2);
813 		if (err)
814 			goto done;
815 	}
816 
817 	err = got_diffreg(&result, f1, f2, a->diff_algo, a->ignore_ws,
818 	    a->force_text);
819 	if (err)
820 		goto done;
821 
822 	err = get_diffstat(a, path, result->result, a->force_text, status);
823 
824 done:
825 	if (result) {
826 		const struct got_error *free_err;
827 
828 		free_err = got_diffreg_result_free(result);
829 		if (free_err && err == NULL)
830 			err = free_err;
831 	}
832 	if (err)
833 		free(path);
834 	return err;
835 }
836 
837 const struct got_error *
838 got_diff_tree_collect_changed_paths(void *arg, struct got_blob_object *blob1,
839     struct got_blob_object *blob2, FILE *f1, FILE *f2,
840     struct got_object_id *id1, struct got_object_id *id2,
841     const char *label1, const char *label2,
842     mode_t mode1, mode_t mode2, struct got_repository *repo)
843 {
844 	const struct got_error *err = NULL;
845 	struct got_pathlist_head *paths = arg;
846 	struct got_diff_changed_path *change = NULL;
847 	char *path = NULL;
848 
849 	path = strdup(label2 ? label2 : label1);
850 	if (path == NULL)
851 		return got_error_from_errno("strdup");
852 
853 	change = malloc(sizeof(*change));
854 	if (change == NULL) {
855 		err = got_error_from_errno("malloc");
856 		goto done;
857 	}
858 
859 	change->status = GOT_STATUS_NO_CHANGE;
860 	if (id1 == NULL)
861 		change->status = GOT_STATUS_ADD;
862 	else if (id2 == NULL)
863 		change->status = GOT_STATUS_DELETE;
864 	else {
865 		if (got_object_id_cmp(id1, id2) != 0)
866 			change->status = GOT_STATUS_MODIFY;
867 		else if (mode1 != mode2)
868 			change->status = GOT_STATUS_MODE_CHANGE;
869 	}
870 
871 	err = got_pathlist_append(paths, path, change);
872 done:
873 	if (err) {
874 		free(path);
875 		free(change);
876 	}
877 	return err;
878 }
879 
880 const struct got_error *
881 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
882     FILE *f1, FILE *f2, int fd1, int fd2,
883     const char *label1, const char *label2,
884     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
885     int diff_content)
886 {
887 	const struct got_error *err = NULL;
888 	struct got_tree_entry *te1 = NULL;
889 	struct got_tree_entry *te2 = NULL;
890 	char *l1 = NULL, *l2 = NULL;
891 	int tidx1 = 0, tidx2 = 0;
892 
893 	if (tree1) {
894 		te1 = got_object_tree_get_entry(tree1, 0);
895 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
896 		    te1->name) == -1)
897 			return got_error_from_errno("asprintf");
898 	}
899 	if (tree2) {
900 		te2 = got_object_tree_get_entry(tree2, 0);
901 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
902 		    te2->name) == -1) {
903 			err = got_error_from_errno("asprintf");
904 			goto done;
905 		}
906 	}
907 
908 	do {
909 		if (te1) {
910 			struct got_tree_entry *te = NULL;
911 
912 			if (tree2)
913 				te = got_object_tree_find_entry(tree2,
914 				    te1->name);
915 			if (te) {
916 				free(l2);
917 				l2 = NULL;
918 				if (te && asprintf(&l2, "%s%s%s", label2,
919 				    label2[0] ? "/" : "", te->name) == -1) {
920 					err = got_error_from_errno("asprintf");
921 					goto done;
922 				}
923 			}
924 
925 			err = diff_entry_old_new(te1, te, f1, f2, fd1, fd2,
926 			    l1, l2, repo, cb, cb_arg, diff_content);
927 			if (err)
928 				break;
929 		}
930 
931 		if (te2) {
932 			struct got_tree_entry *te = NULL;
933 
934 			if (tree1)
935 				te = got_object_tree_find_entry(tree1,
936 				    te2->name);
937 
938 			free(l2);
939 			l2 = NULL;
940 			if (te) {
941 				if (asprintf(&l2, "%s%s%s", label2,
942 				    label2[0] ? "/" : "", te->name) == -1) {
943 					err = got_error_from_errno("asprintf");
944 					goto done;
945 				}
946 			} else {
947 				if (asprintf(&l2, "%s%s%s", label2,
948 				    label2[0] ? "/" : "", te2->name) == -1) {
949 					err = got_error_from_errno("asprintf");
950 					goto done;
951 				}
952 			}
953 
954 			err = diff_entry_new_old(te2, te, f1, f2, fd2, l2,
955 			    repo, cb, cb_arg, diff_content);
956 			if (err)
957 				break;
958 		}
959 
960 		free(l1);
961 		l1 = NULL;
962 		if (te1) {
963 			tidx1++;
964 			te1 = got_object_tree_get_entry(tree1, tidx1);
965 			if (te1 &&
966 			    asprintf(&l1, "%s%s%s", label1,
967 			    label1[0] ? "/" : "", te1->name) == -1) {
968 				err = got_error_from_errno("asprintf");
969 				goto done;
970 			}
971 		}
972 
973 		free(l2);
974 		l2 = NULL;
975 		if (te2) {
976 			tidx2++;
977 			te2 = got_object_tree_get_entry(tree2, tidx2);
978 			if (te2 &&
979 			    asprintf(&l2, "%s%s%s", label2,
980 			    label2[0] ? "/" : "", te2->name) == -1) {
981 				err = got_error_from_errno("asprintf");
982 				goto done;
983 			}
984 		}
985 	} while (te1 || te2);
986 
987 done:
988 	free(l1);
989 	free(l2);
990 	return err;
991 }
992 
993 const struct got_error *
994 got_diff_objects_as_blobs(struct got_diff_line **lines, size_t *nlines,
995     FILE *f1, FILE *f2, int fd1, int fd2,
996     struct got_object_id *id1, struct got_object_id *id2,
997     const char *label1, const char *label2,
998     enum got_diff_algorithm diff_algo, int diff_context,
999     int ignore_whitespace, int force_text_diff, int show_diffstat,
1000     struct got_diffstat_cb_arg *ds, struct got_repository *repo, FILE *outfile)
1001 {
1002 	const struct got_error *err;
1003 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1004 
1005 	if (id1 == NULL && id2 == NULL)
1006 		return got_error(GOT_ERR_NO_OBJ);
1007 
1008 	if (id1) {
1009 		err = got_object_open_as_blob(&blob1, repo, id1, 8192, fd1);
1010 		if (err)
1011 			goto done;
1012 	}
1013 	if (id2) {
1014 		err = got_object_open_as_blob(&blob2, repo, id2, 8192, fd2);
1015 		if (err)
1016 			goto done;
1017 	}
1018 	err = got_diff_blob(lines, nlines, blob1, blob2, f1, f2, label1, label2,
1019 	    diff_algo, diff_context, ignore_whitespace, force_text_diff,
1020 	    show_diffstat, ds, outfile);
1021 done:
1022 	if (blob1)
1023 		got_object_blob_close(blob1);
1024 	if (blob2)
1025 		got_object_blob_close(blob2);
1026 	return err;
1027 }
1028 
1029 static const struct got_error *
1030 diff_paths(struct got_tree_object *tree1, struct got_tree_object *tree2,
1031     FILE *f1, FILE *f2, int fd1, int fd2, struct got_pathlist_head *paths,
1032     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
1033 {
1034 	const struct got_error *err = NULL;
1035 	struct got_pathlist_entry *pe;
1036 	struct got_object_id *id1 = NULL, *id2 = NULL;
1037 	struct got_tree_object *subtree1 = NULL, *subtree2 = NULL;
1038 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1039 
1040 	TAILQ_FOREACH(pe, paths, entry) {
1041 		int type1 = GOT_OBJ_TYPE_ANY, type2 = GOT_OBJ_TYPE_ANY;
1042 		mode_t mode1 = 0, mode2 = 0;
1043 
1044 		free(id1);
1045 		id1 = NULL;
1046 		free(id2);
1047 		id2 = NULL;
1048 		if (subtree1) {
1049 			got_object_tree_close(subtree1);
1050 			subtree1 = NULL;
1051 		}
1052 		if (subtree2) {
1053 			got_object_tree_close(subtree2);
1054 			subtree2 = NULL;
1055 		}
1056 		if (blob1) {
1057 			got_object_blob_close(blob1);
1058 			blob1 = NULL;
1059 		}
1060 		if (blob2) {
1061 			got_object_blob_close(blob2);
1062 			blob2 = NULL;
1063 		}
1064 
1065 		err = got_object_tree_find_path(&id1, &mode1, repo, tree1,
1066 		    pe->path);
1067 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1068 			goto done;
1069 		err = got_object_tree_find_path(&id2, &mode2, repo, tree2,
1070 		    pe->path);
1071 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1072 			goto done;
1073 		if (id1 == NULL && id2 == NULL) {
1074 			err = got_error_path(pe->path, GOT_ERR_NO_TREE_ENTRY);
1075 			goto done;
1076 		}
1077 		if (id1) {
1078 			err = got_object_get_type(&type1, repo, id1);
1079 			if (err)
1080 				goto done;
1081 		}
1082 		if (id2) {
1083 			err = got_object_get_type(&type2, repo, id2);
1084 			if (err)
1085 				goto done;
1086 		}
1087 		if (type1 == GOT_OBJ_TYPE_ANY &&
1088 		    type2 == GOT_OBJ_TYPE_ANY) {
1089 			err = got_error_path(pe->path, GOT_ERR_NO_OBJ);
1090 			goto done;
1091 		} else if (type1 != GOT_OBJ_TYPE_ANY &&
1092 		    type2 != GOT_OBJ_TYPE_ANY && type1 != type2) {
1093 			err = got_error(GOT_ERR_OBJ_TYPE);
1094 			goto done;
1095 		}
1096 
1097 		if (type1 == GOT_OBJ_TYPE_BLOB ||
1098 		    type2 == GOT_OBJ_TYPE_BLOB) {
1099 			if (id1) {
1100 				err = got_object_open_as_blob(&blob1, repo,
1101 				    id1, 8192, fd1);
1102 				if (err)
1103 					goto done;
1104 			}
1105 			if (id2) {
1106 				err = got_object_open_as_blob(&blob2, repo,
1107 				    id2, 8192, fd2);
1108 				if (err)
1109 					goto done;
1110 			}
1111 			err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2,
1112 			    id1 ? pe->path : "/dev/null",
1113 			    id2 ? pe->path : "/dev/null",
1114 			    mode1, mode2, repo);
1115 			if (err)
1116 				goto done;
1117 		} else if (type1 == GOT_OBJ_TYPE_TREE ||
1118 		    type2 == GOT_OBJ_TYPE_TREE) {
1119 			if (id1) {
1120 				err = got_object_open_as_tree(&subtree1, repo,
1121 				    id1);
1122 				if (err)
1123 					goto done;
1124 			}
1125 			if (id2) {
1126 				err = got_object_open_as_tree(&subtree2, repo,
1127 				    id2);
1128 				if (err)
1129 					goto done;
1130 			}
1131 			err = got_diff_tree(subtree1, subtree2, f1, f2,
1132 			    fd1, fd2,
1133 			    id1 ? pe->path : "/dev/null",
1134 			    id2 ? pe->path : "/dev/null",
1135 			    repo, cb, cb_arg, 1);
1136 			if (err)
1137 				goto done;
1138 		} else {
1139 			err = got_error(GOT_ERR_OBJ_TYPE);
1140 			goto done;
1141 		}
1142 	}
1143 done:
1144 	free(id1);
1145 	free(id2);
1146 	if (subtree1)
1147 		got_object_tree_close(subtree1);
1148 	if (subtree2)
1149 		got_object_tree_close(subtree2);
1150 	if (blob1)
1151 		got_object_blob_close(blob1);
1152 	if (blob2)
1153 		got_object_blob_close(blob2);
1154 	return err;
1155 }
1156 
1157 static const struct got_error *
1158 show_object_id(struct got_diff_line **lines, size_t *nlines,
1159     const char *obj_typestr, int ch, const char *id_str, FILE *outfile)
1160 {
1161 	const struct got_error *err;
1162 	int n;
1163 	off_t outoff = 0;
1164 
1165 	n = fprintf(outfile, "%s %c %s\n", obj_typestr, ch, id_str);
1166 	if (n < 0)
1167 		return got_error_from_errno("fprintf");
1168 
1169 	if (lines != NULL && *lines != NULL) {
1170 		if (*nlines == 0) {
1171 			err = add_line_metadata(lines, nlines, 0,
1172 			    GOT_DIFF_LINE_META);
1173 			if (err)
1174 				return err;
1175 		} else
1176 			outoff = (*lines)[*nlines - 1].offset;
1177 
1178 		outoff += n;
1179 		err = add_line_metadata(lines, nlines, outoff,
1180 		    GOT_DIFF_LINE_META);
1181 		if (err)
1182 			return err;
1183 	}
1184 
1185 	return NULL;
1186 }
1187 
1188 static const struct got_error *
1189 diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1190     FILE *f1, FILE *f2, int fd1, int fd2,
1191     struct got_object_id *id1, struct got_object_id *id2,
1192     struct got_pathlist_head *paths, const char *label1, const char *label2,
1193     int diff_context, int ignore_whitespace, int force_text_diff,
1194     int show_diffstat, struct got_diffstat_cb_arg *dsa,
1195     struct got_repository *repo, FILE *outfile,
1196     enum got_diff_algorithm diff_algo)
1197 {
1198 	const struct got_error *err;
1199 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1200 	struct got_diff_blob_output_unidiff_arg arg;
1201 	int want_linemeta = (lines != NULL && *lines != NULL);
1202 
1203 	if (id1 == NULL && id2 == NULL)
1204 		return got_error(GOT_ERR_NO_OBJ);
1205 
1206 	if (id1) {
1207 		err = got_object_open_as_tree(&tree1, repo, id1);
1208 		if (err)
1209 			goto done;
1210 	}
1211 	if (id2) {
1212 		err = got_object_open_as_tree(&tree2, repo, id2);
1213 		if (err)
1214 			goto done;
1215 	}
1216 
1217 	arg.diff_algo = diff_algo;
1218 	arg.diff_context = diff_context;
1219 	arg.ignore_whitespace = ignore_whitespace;
1220 	arg.force_text_diff = force_text_diff;
1221 	arg.show_diffstat = show_diffstat;
1222 	arg.diffstat = dsa;
1223 	arg.outfile = outfile;
1224 	if (want_linemeta) {
1225 		arg.lines = *lines;
1226 		arg.nlines = *nlines;
1227 	} else {
1228 		arg.lines = NULL;
1229 		arg.nlines = 0;
1230 	}
1231 	if (paths == NULL || TAILQ_EMPTY(paths))
1232 		err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2, label1,
1233 		    label2, repo, got_diff_blob_output_unidiff, &arg, 1);
1234 	else
1235 		err = diff_paths(tree1, tree2, f1, f2, fd1, fd2, paths, repo,
1236 		    got_diff_blob_output_unidiff, &arg);
1237 	if (want_linemeta) {
1238 		*lines = arg.lines; /* was likely re-allocated */
1239 		*nlines = arg.nlines;
1240 	}
1241 done:
1242 	if (tree1)
1243 		got_object_tree_close(tree1);
1244 	if (tree2)
1245 		got_object_tree_close(tree2);
1246 	return err;
1247 }
1248 
1249 const struct got_error *
1250 got_diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1251     FILE *f1, FILE *f2, int fd1, int fd2,
1252     struct got_object_id *id1, struct got_object_id *id2,
1253     struct got_pathlist_head *paths, const char *label1, const char *label2,
1254     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
1255     int force_text_diff, int show_diffstat, struct got_diffstat_cb_arg *dsa,
1256     struct got_repository *repo, FILE *outfile)
1257 {
1258 	const struct got_error *err;
1259 	char *idstr = NULL;
1260 
1261 	if (id1 == NULL && id2 == NULL)
1262 		return got_error(GOT_ERR_NO_OBJ);
1263 
1264 	if (id1) {
1265 		err = got_object_id_str(&idstr, id1);
1266 		if (err)
1267 			goto done;
1268 		err = show_object_id(lines, nlines, "tree", '-', idstr, outfile);
1269 		if (err)
1270 			goto done;
1271 		free(idstr);
1272 		idstr = NULL;
1273 	} else {
1274 		err = show_object_id(lines, nlines, "tree", '-', "/dev/null",
1275 		    outfile);
1276 		if (err)
1277 			goto done;
1278 	}
1279 
1280 	if (id2) {
1281 		err = got_object_id_str(&idstr, id2);
1282 		if (err)
1283 			goto done;
1284 		err = show_object_id(lines, nlines, "tree", '+', idstr, outfile);
1285 		if (err)
1286 			goto done;
1287 		free(idstr);
1288 		idstr = NULL;
1289 	} else {
1290 		err = show_object_id(lines, nlines, "tree", '+', "/dev/null",
1291 		    outfile);
1292 		if (err)
1293 			goto done;
1294 	}
1295 
1296 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2, id1, id2,
1297 	    paths, label1, label2, diff_context, ignore_whitespace,
1298 	    force_text_diff, show_diffstat, dsa, repo, outfile, diff_algo);
1299 done:
1300 	free(idstr);
1301 	return err;
1302 }
1303 
1304 const struct got_error *
1305 got_diff_objects_as_commits(struct got_diff_line **lines, size_t *nlines,
1306     FILE *f1, FILE *f2, int fd1, int fd2,
1307     struct got_object_id *id1, struct got_object_id *id2,
1308     struct got_pathlist_head *paths, enum got_diff_algorithm diff_algo,
1309     int diff_context, int ignore_whitespace, int force_text_diff,
1310     int show_diffstat, struct got_diffstat_cb_arg *dsa,
1311     struct got_repository *repo, FILE *outfile)
1312 {
1313 	const struct got_error *err;
1314 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
1315 	char *idstr = NULL;
1316 
1317 	if (id2 == NULL)
1318 		return got_error(GOT_ERR_NO_OBJ);
1319 
1320 	if (id1) {
1321 		err = got_object_open_as_commit(&commit1, repo, id1);
1322 		if (err)
1323 			goto done;
1324 		err = got_object_id_str(&idstr, id1);
1325 		if (err)
1326 			goto done;
1327 		err = show_object_id(lines, nlines, "commit", '-', idstr,
1328 		    outfile);
1329 		if (err)
1330 			goto done;
1331 		free(idstr);
1332 		idstr = NULL;
1333 	} else {
1334 		err = show_object_id(lines, nlines, "commit", '-', "/dev/null",
1335 		    outfile);
1336 		if (err)
1337 			goto done;
1338 	}
1339 
1340 	err = got_object_open_as_commit(&commit2, repo, id2);
1341 	if (err)
1342 		goto done;
1343 
1344 	err = got_object_id_str(&idstr, id2);
1345 	if (err)
1346 		goto done;
1347 	err = show_object_id(lines, nlines, "commit", '+', idstr, outfile);
1348 	if (err)
1349 		goto done;
1350 
1351 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2,
1352 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
1353 	    got_object_commit_get_tree_id(commit2), paths, "", "",
1354 	    diff_context, ignore_whitespace, force_text_diff, show_diffstat,
1355 	    dsa, repo, outfile, diff_algo);
1356 done:
1357 	if (commit1)
1358 		got_object_commit_close(commit1);
1359 	if (commit2)
1360 		got_object_commit_close(commit2);
1361 	free(idstr);
1362 	return err;
1363 }
1364 
1365 const struct got_error *
1366 got_diff_files(struct got_diffreg_result **resultp,
1367     FILE *f1, int f1_exists, const char *label1, FILE *f2, int f2_exists,
1368     const char *label2, int diff_context, int ignore_whitespace,
1369     int force_text_diff, FILE *outfile, enum got_diff_algorithm diff_algo)
1370 {
1371 	const struct got_error *err = NULL;
1372 	struct got_diffreg_result *diffreg_result = NULL;
1373 
1374 	if (resultp)
1375 		*resultp = NULL;
1376 
1377 	if (outfile) {
1378 		fprintf(outfile, "file - %s\n",
1379 		    f1_exists ? label1 : "/dev/null");
1380 		fprintf(outfile, "file + %s\n",
1381 		    f2_exists ? label2 : "/dev/null");
1382 	}
1383 
1384 	err = got_diffreg(&diffreg_result, f1, f2, diff_algo,
1385 	    ignore_whitespace, force_text_diff);
1386 	if (err)
1387 		goto done;
1388 
1389 	if (outfile) {
1390 		err = got_diffreg_output(NULL, NULL, diffreg_result,
1391 		    f1_exists, f2_exists, label1, label2,
1392 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
1393 		if (err)
1394 			goto done;
1395 	}
1396 
1397 done:
1398 	if (resultp && err == NULL)
1399 		*resultp = diffreg_result;
1400 	else if (diffreg_result) {
1401 		const struct got_error *free_err;
1402 
1403 		free_err = got_diffreg_result_free(diffreg_result);
1404 		if (free_err && err == NULL)
1405 			err = free_err;
1406 	}
1407 
1408 	return err;
1409 }