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 <sha1.h>
25 #include <zlib.h>
26 
27 #include "got_object.h"
28 #include "got_repository.h"
29 #include "got_error.h"
30 #include "got_diff.h"
31 #include "got_path.h"
32 #include "got_cancel.h"
33 #include "got_worktree.h"
34 #include "got_opentemp.h"
35 
36 #include "got_lib_diff.h"
37 #include "got_lib_delta.h"
38 #include "got_lib_inflate.h"
39 #include "got_lib_object.h"
40 
41 #ifndef MAX
42 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
43 #endif
44 
45 static const struct got_error *
46 add_line_metadata(struct got_diff_line **lines, size_t *nlines,
47     off_t off, uint8_t type)
48 {
49 	struct got_diff_line *p;
50 
51 	p = reallocarray(*lines, *nlines + 1, sizeof(**lines));
52 	if (p == NULL)
53 		return got_error_from_errno("reallocarray");
54 	*lines = p;
55 	(*lines)[*nlines].offset = off;
56 	(*lines)[*nlines].type = type;
57 	(*nlines)++;
58 
59 	return NULL;
60 }
61 
62 static void
63 diffstat_field_width(size_t *maxlen, int *add_cols, int *rm_cols, size_t len,
64     uint32_t add, uint32_t rm)
65 {
66 	int d1 = 1, d2 = 1;
67 
68 	if (maxlen)
69 		*maxlen = MAX(*maxlen, len);
70 
71 	while (add /= 10)
72 		++d1;
73 	*add_cols = MAX(*add_cols, d1);
74 
75 	while (rm /= 10)
76 		++d2;
77 	*rm_cols = MAX(*rm_cols, d2);
78 }
79 
80 static const struct got_error *
81 get_diffstat(struct got_diffstat_cb_arg *ds, const char *path,
82     struct diff_result *r, int force_text, int status)
83 {
84 	const struct got_error *err;
85 	struct got_pathlist_entry *pe;
86 	struct got_diff_changed_path *change = NULL;
87 	int flags = (r->left->atomizer_flags | r->right->atomizer_flags);
88 	int isbin = (flags & DIFF_ATOMIZER_FOUND_BINARY_DATA);
89 	int i;
90 
91 	change = calloc(1, sizeof(*change));
92 	if (change == NULL)
93 		return got_error_from_errno("calloc");
94 
95 	if (!isbin || force_text) {
96 		for (i = 0; i < r->chunks.len; ++i) {
97 			struct diff_chunk *c;
98 			int clc, crc;
99 
100 			c = diff_chunk_get(r, i);
101 			clc = diff_chunk_get_left_count(c);
102 			crc = diff_chunk_get_right_count(c);
103 
104 			if (crc && !clc)
105 				change->add += crc;
106 			if (clc && !crc)
107 				change->rm += clc;
108 		}
109 	}
110 
111 	change->status = status;
112 	ds->ins += change->add;
113 	ds->del += change->rm;
114 	++ds->nfiles;
115 
116 	err = got_pathlist_append(ds->paths, path, change);
117 	if (err) {
118 		free(change);
119 		return err;
120 	}
121 
122 	pe = TAILQ_LAST(ds->paths, got_pathlist_head);
123 	diffstat_field_width(&ds->max_path_len, &ds->add_cols, &ds->rm_cols,
124 	    pe->path_len, change->add, change->rm);
125 
126 	return NULL;
127 }
128 
129 static const struct got_error *
130 diff_blobs(struct got_diff_line **lines, size_t *nlines,
131     struct got_diffreg_result **resultp, struct got_blob_object *blob1,
132     struct got_blob_object *blob2, FILE *f1, FILE *f2,
133     const char *label1, const char *label2, mode_t mode1, mode_t mode2,
134     int diff_context, int ignore_whitespace, int force_text_diff,
135     int show_diffstat, struct got_diffstat_cb_arg *ds, FILE *outfile,
136     enum got_diff_algorithm diff_algo)
137 {
138 	const struct got_error *err = NULL, *free_err;
139 	char hex1[SHA1_DIGEST_STRING_LENGTH];
140 	char hex2[SHA1_DIGEST_STRING_LENGTH];
141 	const char *idstr1 = NULL, *idstr2 = NULL;
142 	char *modestr1 = NULL, *modestr2 = NULL;
143 	off_t size1, size2;
144 	struct got_diffreg_result *result = NULL;
145 	off_t outoff = 0;
146 	int n;
147 
148 	if (lines && *lines && *nlines > 0)
149 		outoff = (*lines)[*nlines - 1].offset;
150 	else if (lines) {
151 		err = add_line_metadata(lines, nlines, 0, GOT_DIFF_LINE_NONE);
152 		if (err)
153 			goto done;
154 	}
155 
156 	if (resultp)
157 		*resultp = NULL;
158 
159 	if (f1) {
160 		err = got_opentemp_truncate(f1);
161 		if (err)
162 			goto done;
163 	}
164 	if (f2) {
165 		err = got_opentemp_truncate(f2);
166 		if (err)
167 			goto done;
168 	}
169 
170 	size1 = 0;
171 	if (blob1) {
172 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
173 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
174 		    blob1);
175 		if (err)
176 			goto done;
177 	} else
178 		idstr1 = "/dev/null";
179 
180 	size2 = 0;
181 	if (blob2) {
182 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
183 		err = got_object_blob_dump_to_file(&size2, NULL, NULL, f2,
184 		    blob2);
185 		if (err)
186 			goto done;
187 	} else
188 		idstr2 = "/dev/null";
189 
190 	if (outfile) {
191 		int modebits;
192 
193 		if (mode1 && mode1 != mode2) {
194 			if (S_ISLNK(mode1))
195 				modebits = S_IFLNK;
196 			else
197 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
198 			if (asprintf(&modestr1, " (mode %o)",
199 			    mode1 & modebits) == -1) {
200 				err = got_error_from_errno("asprintf");
201 				goto done;
202 			}
203 		}
204 		if (mode2 && mode1 != mode2) {
205 			if (S_ISLNK(mode2))
206 				modebits = S_IFLNK;
207 			else
208 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
209 			if (asprintf(&modestr2, " (mode %o)",
210 			    mode2 & modebits) == -1) {
211 				err = got_error_from_errno("asprintf");
212 				goto done;
213 			}
214 		}
215 		n = fprintf(outfile, "blob - %s%s\n", idstr1,
216 		    modestr1 ? modestr1 : "");
217 		if (n < 0)
218 			goto done;
219 		outoff += n;
220 		if (lines) {
221 			err = add_line_metadata(lines, nlines, outoff,
222 			    GOT_DIFF_LINE_BLOB_MIN);
223 			if (err)
224 				goto done;
225 		}
226 
227 		n = fprintf(outfile, "blob + %s%s\n", idstr2,
228 		    modestr2 ? modestr2 : "");
229 		if (n < 0)
230 			goto done;
231 		outoff += n;
232 		if (lines) {
233 			err = add_line_metadata(lines, nlines, outoff,
234 			    GOT_DIFF_LINE_BLOB_PLUS);
235 			if (err)
236 				goto done;
237 		}
238 	}
239 
240 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
241 	     force_text_diff);
242 	if (err)
243 		goto done;
244 
245 	if (show_diffstat) {
246 		char	*path = NULL;
247 		int	 status = GOT_STATUS_NO_CHANGE;
248 
249 		/*
250 		 * Ignore 'm'ode status change: if there's no accompanying
251 		 * content change, there'll be no diffstat, and if there
252 		 * are actual changes, 'M'odified takes precedence.
253 		 */
254 		if (blob1 == NULL)
255 			status = GOT_STATUS_ADD;
256 		else if (blob2 == NULL)
257 			status = GOT_STATUS_DELETE;
258 		else
259 			status = GOT_STATUS_MODIFY;
260 
261 		if (label1 == NULL && label2 == NULL) {
262 			/* diffstat of blobs, show hash instead of path */
263 			if (asprintf(&path, "%.10s -> %.10s",
264 			    idstr1, idstr2) == -1) {
265 				err = got_error_from_errno("asprintf");
266 				goto done;
267 			}
268 		} else {
269 			if (label2 != NULL &&
270 			    (status != GOT_STATUS_DELETE || label1 == NULL))
271 				path = strdup(label2);
272 			else
273 				path = strdup(label1);
274 			if (path == NULL) {
275 				err = got_error_from_errno("strdup");
276 				goto done;
277 			}
278 		}
279 
280 		err = get_diffstat(ds, path, result->result, force_text_diff,
281 		    status);
282 		if (err) {
283 			free(path);
284 			goto done;
285 		}
286 	}
287 
288 	if (outfile) {
289 		err = got_diffreg_output(lines, nlines, result,
290 		    blob1 != NULL, blob2 != NULL,
291 		    label1 ? label1 : idstr1,
292 		    label2 ? label2 : idstr2,
293 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
294 		if (err)
295 			goto done;
296 	}
297 
298 done:
299 	free(modestr1);
300 	free(modestr2);
301 	if (resultp && err == NULL)
302 		*resultp = result;
303 	else if (result) {
304 		free_err = got_diffreg_result_free(result);
305 		if (free_err && err == NULL)
306 			err = free_err;
307 	}
308 
309 	return err;
310 }
311 
312 const struct got_error *
313 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
314     struct got_blob_object *blob2, FILE *f1, FILE *f2,
315     struct got_object_id *id1, struct got_object_id *id2,
316     const char *label1, const char *label2, mode_t mode1, mode_t mode2,
317     struct got_repository *repo)
318 {
319 	struct got_diff_blob_output_unidiff_arg *a = arg;
320 
321 	return diff_blobs(&a->lines, &a->nlines, NULL,
322 	    blob1, blob2, f1, f2, label1, label2, mode1, mode2, a->diff_context,
323 	    a->ignore_whitespace, a->force_text_diff, a->show_diffstat,
324 	    a->diffstat, a->outfile, a->diff_algo);
325 }
326 
327 const struct got_error *
328 got_diff_blob(struct got_diff_line **lines, size_t*nlines,
329     struct got_blob_object *blob1, struct got_blob_object *blob2,
330     FILE *f1, FILE *f2, const char *label1, const char *label2,
331     enum got_diff_algorithm diff_algo, int diff_context,
332     int ignore_whitespace, int force_text_diff, int show_diffstat,
333     struct got_diffstat_cb_arg *ds, FILE *outfile)
334 {
335 	return diff_blobs(lines, nlines, NULL, blob1, blob2, f1, f2,
336 	    label1, label2, 0, 0, diff_context, ignore_whitespace,
337 	    force_text_diff, show_diffstat, ds, outfile, diff_algo);
338 }
339 
340 static const struct got_error *
341 diff_blob_file(struct got_diffreg_result **resultp,
342     struct got_blob_object *blob1, FILE *f1, off_t size1, const char *label1,
343     FILE *f2, int f2_exists, struct stat *sb2, const char *label2,
344     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
345     int force_text_diff, int show_diffstat, struct got_diffstat_cb_arg *ds,
346     FILE *outfile)
347 {
348 	const struct got_error *err = NULL, *free_err;
349 	char hex1[SHA1_DIGEST_STRING_LENGTH];
350 	const char *idstr1 = NULL;
351 	struct got_diffreg_result *result = NULL;
352 
353 	if (resultp)
354 		*resultp = NULL;
355 
356 	if (blob1)
357 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
358 	else
359 		idstr1 = "/dev/null";
360 
361 	if (outfile) {
362 		char	*mode = NULL;
363 
364 		/* display file mode for new added files only */
365 		if (f2_exists && blob1 == NULL) {
366 			int mmask = (S_IRWXU | S_IRWXG | S_IRWXO);
367 
368 			if (S_ISLNK(sb2->st_mode))
369 				mmask = S_IFLNK;
370 			if (asprintf(&mode, " (mode %o)",
371 			    sb2->st_mode & mmask) == -1)
372 				return got_error_from_errno("asprintf");
373 		}
374 		fprintf(outfile, "blob - %s\n", label1 ? label1 : idstr1);
375 		fprintf(outfile, "file + %s%s\n",
376 		    f2_exists ? label2 : "/dev/null", mode ? mode : "");
377 		free(mode);
378 	}
379 
380 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
381 	    force_text_diff);
382 	if (err)
383 		goto done;
384 
385 	if (outfile) {
386 		err = got_diffreg_output(NULL, NULL, result,
387 		    blob1 != NULL, f2_exists,
388 		    label2, /* show local file's path, not a blob ID */
389 		    label2, GOT_DIFF_OUTPUT_UNIDIFF,
390 		    diff_context, outfile);
391 		if (err)
392 			goto done;
393 	}
394 
395 	if (show_diffstat) {
396 		char	*path = NULL;
397 		int	 status = GOT_STATUS_NO_CHANGE;
398 
399 		/*
400 		 * Ignore 'm'ode status change: if there's no accompanying
401 		 * content change, there'll be no diffstat, and if there
402 		 * are actual changes, 'M'odified takes precedence.
403 		 */
404 		if (blob1 == NULL)
405 			status = GOT_STATUS_ADD;
406 		else if (!f2_exists)
407 			status = GOT_STATUS_DELETE;
408 		else
409 			status = GOT_STATUS_MODIFY;
410 
411 		if (label2 != NULL &&
412 		    (status != GOT_STATUS_DELETE || label1 == NULL))
413 			path = strdup(label2);
414 		else
415 			path = strdup(label1);
416 		if (path == NULL) {
417 			err = got_error_from_errno("strdup");
418 			goto done;
419 		}
420 
421 		err = get_diffstat(ds, path, result->result, force_text_diff,
422 		    status);
423 		if (err) {
424 			free(path);
425 			goto done;
426 		}
427 	}
428 
429 done:
430 	if (resultp && err == NULL)
431 		*resultp = result;
432 	else if (result) {
433 		free_err = got_diffreg_result_free(result);
434 		if (free_err && err == NULL)
435 			err = free_err;
436 	}
437 	return err;
438 }
439 
440 const struct got_error *
441 got_diff_blob_file(struct got_blob_object *blob1, FILE *f1, off_t size1,
442     const char *label1, FILE *f2, int f2_exists, struct stat *sb2,
443     const char *label2, enum got_diff_algorithm diff_algo, int diff_context,
444     int ignore_whitespace, int force_text_diff, int show_diffstat,
445     struct got_diffstat_cb_arg *ds, FILE *outfile)
446 {
447 	return diff_blob_file(NULL, blob1, f1, size1, label1, f2, f2_exists,
448 	    sb2, label2, diff_algo, diff_context, ignore_whitespace,
449 	    force_text_diff, show_diffstat, ds, outfile);
450 }
451 
452 static const struct got_error *
453 diff_added_blob(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
454     const char *label, mode_t mode, struct got_repository *repo,
455     got_diff_blob_cb cb, void *cb_arg)
456 {
457 	const struct got_error *err;
458 	struct got_blob_object  *blob = NULL;
459 	struct got_object *obj = NULL;
460 
461 	err = got_object_open(&obj, repo, id);
462 	if (err)
463 		return err;
464 
465 	err = got_object_blob_open(&blob, repo, obj, 8192, fd2);
466 	if (err)
467 		goto done;
468 	err = cb(cb_arg, NULL, blob, f1, f2, NULL, id,
469 	    NULL, label, 0, mode, repo);
470 done:
471 	got_object_close(obj);
472 	if (blob)
473 		got_object_blob_close(blob);
474 	return err;
475 }
476 
477 static const struct got_error *
478 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
479     FILE *f1, FILE *f2, int fd1, int fd2,
480     const char *label1, const char *label2,
481     mode_t mode1, mode_t mode2, struct got_repository *repo,
482     got_diff_blob_cb cb, void *cb_arg)
483 {
484 	const struct got_error *err;
485 	struct got_object *obj1 = NULL;
486 	struct got_object *obj2 = NULL;
487 	struct got_blob_object *blob1 = NULL;
488 	struct got_blob_object *blob2 = NULL;
489 
490 	err = got_object_open(&obj1, repo, id1);
491 	if (err)
492 		return err;
493 
494 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
495 		err = got_error(GOT_ERR_OBJ_TYPE);
496 		goto done;
497 	}
498 
499 	err = got_object_open(&obj2, repo, id2);
500 	if (err)
501 		goto done;
502 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
503 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
504 		goto done;
505 	}
506 
507 	err = got_object_blob_open(&blob1, repo, obj1, 8192, fd1);
508 	if (err)
509 		goto done;
510 
511 	err = got_object_blob_open(&blob2, repo, obj2, 8192, fd2);
512 	if (err)
513 		goto done;
514 
515 	err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2, label1, label2,
516 	    mode1, mode2, repo);
517 done:
518 	if (obj1)
519 		got_object_close(obj1);
520 	if (obj2)
521 		got_object_close(obj2);
522 	if (blob1)
523 		got_object_blob_close(blob1);
524 	if (blob2)
525 		got_object_blob_close(blob2);
526 	return err;
527 }
528 
529 static const struct got_error *
530 diff_deleted_blob(struct got_object_id *id, FILE *f1, int fd1,
531    FILE *f2, const char *label, mode_t mode, struct got_repository *repo,
532    got_diff_blob_cb cb, void *cb_arg)
533 {
534 	const struct got_error *err;
535 	struct got_blob_object  *blob = NULL;
536 	struct got_object *obj = NULL;
537 
538 	err = got_object_open(&obj, repo, id);
539 	if (err)
540 		return err;
541 
542 	err = got_object_blob_open(&blob, repo, obj, 8192, fd1);
543 	if (err)
544 		goto done;
545 	err = cb(cb_arg, blob, NULL, f1, f2, id, NULL, label, NULL,
546 	    mode, 0, repo);
547 done:
548 	got_object_close(obj);
549 	if (blob)
550 		got_object_blob_close(blob);
551 	return err;
552 }
553 
554 static const struct got_error *
555 diff_added_tree(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
556     const char *label, struct got_repository *repo, got_diff_blob_cb cb,
557     void *cb_arg, int diff_content)
558 {
559 	const struct got_error *err = NULL;
560 	struct got_object *treeobj = NULL;
561 	struct got_tree_object *tree = NULL;
562 
563 	err = got_object_open(&treeobj, repo, id);
564 	if (err)
565 		goto done;
566 
567 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
568 		err = got_error(GOT_ERR_OBJ_TYPE);
569 		goto done;
570 	}
571 
572 	err = got_object_tree_open(&tree, repo, treeobj);
573 	if (err)
574 		goto done;
575 
576 	err = got_diff_tree(NULL, tree, f1, f2, -1, fd2, NULL, label,
577 	    repo, cb, cb_arg, diff_content);
578 done:
579 	if (tree)
580 		got_object_tree_close(tree);
581 	if (treeobj)
582 		got_object_close(treeobj);
583 	return err;
584 }
585 
586 static const struct got_error *
587 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
588     FILE *f1, FILE *f2, int fd1, int fd2,
589     const char *label1, const char *label2,
590     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
591     int diff_content)
592 {
593 	const struct got_error *err;
594 	struct got_object *treeobj1 = NULL;
595 	struct got_object *treeobj2 = NULL;
596 	struct got_tree_object *tree1 = NULL;
597 	struct got_tree_object *tree2 = NULL;
598 
599 	err = got_object_open(&treeobj1, repo, id1);
600 	if (err)
601 		goto done;
602 
603 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
604 		err = got_error(GOT_ERR_OBJ_TYPE);
605 		goto done;
606 	}
607 
608 	err = got_object_open(&treeobj2, repo, id2);
609 	if (err)
610 		goto done;
611 
612 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
613 		err = got_error(GOT_ERR_OBJ_TYPE);
614 		goto done;
615 	}
616 
617 	err = got_object_tree_open(&tree1, repo, treeobj1);
618 	if (err)
619 		goto done;
620 
621 	err = got_object_tree_open(&tree2, repo, treeobj2);
622 	if (err)
623 		goto done;
624 
625 	err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2,
626 	    label1, label2, repo, cb, cb_arg, diff_content);
627 
628 done:
629 	if (tree1)
630 		got_object_tree_close(tree1);
631 	if (tree2)
632 		got_object_tree_close(tree2);
633 	if (treeobj1)
634 		got_object_close(treeobj1);
635 	if (treeobj2)
636 		got_object_close(treeobj2);
637 	return err;
638 }
639 
640 static const struct got_error *
641 diff_deleted_tree(struct got_object_id *id, FILE *f1, int fd1,
642     FILE *f2, const char *label, struct got_repository *repo,
643     got_diff_blob_cb cb, void *cb_arg, int diff_content)
644 {
645 	const struct got_error *err;
646 	struct got_object *treeobj = NULL;
647 	struct got_tree_object *tree = NULL;
648 
649 	err = got_object_open(&treeobj, repo, id);
650 	if (err)
651 		goto done;
652 
653 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
654 		err = got_error(GOT_ERR_OBJ_TYPE);
655 		goto done;
656 	}
657 
658 	err = got_object_tree_open(&tree, repo, treeobj);
659 	if (err)
660 		goto done;
661 
662 	err = got_diff_tree(tree, NULL, f1, f2, fd1, -1, label, NULL,
663 	    repo, cb, cb_arg, diff_content);
664 done:
665 	if (tree)
666 		got_object_tree_close(tree);
667 	if (treeobj)
668 		got_object_close(treeobj);
669 	return err;
670 }
671 
672 static const struct got_error *
673 diff_kind_mismatch(struct got_object_id *id1, struct got_object_id *id2,
674     const char *label1, const char *label2, struct got_repository *repo,
675     got_diff_blob_cb cb, void *cb_arg)
676 {
677 	/* XXX TODO */
678 	return NULL;
679 }
680 
681 static const struct got_error *
682 diff_entry_old_new(struct got_tree_entry *te1, struct got_tree_entry *te2,
683     FILE *f1, FILE *f2, int fd1, int fd2,
684     const char *label1, const char *label2,
685     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
686     int diff_content)
687 {
688 	const struct got_error *err = NULL;
689 	int id_match;
690 
691 	if (got_object_tree_entry_is_submodule(te1))
692 		return NULL;
693 
694 	if (te2 == NULL) {
695 		if (S_ISDIR(te1->mode))
696 			err = diff_deleted_tree(&te1->id, f1, fd1, f2,
697 			    label1, repo, cb, cb_arg, diff_content);
698 		else {
699 			if (diff_content)
700 				err = diff_deleted_blob(&te1->id, f1, fd1,
701 				    f2, label1, te1->mode, repo, cb, cb_arg);
702 			else
703 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
704 				    &te1->id, NULL, label1, NULL,
705 				    te1->mode, 0, repo);
706 		}
707 		return err;
708 	} else if (got_object_tree_entry_is_submodule(te2))
709 		return NULL;
710 
711 	id_match = (got_object_id_cmp(&te1->id, &te2->id) == 0);
712 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
713 		if (!id_match)
714 			return diff_modified_tree(&te1->id, &te2->id, f1, f2,
715 			    fd1, fd2, label1, label2, repo, cb, cb_arg,
716 			    diff_content);
717 	} else if ((S_ISREG(te1->mode) || S_ISLNK(te1->mode)) &&
718 	    (S_ISREG(te2->mode) || S_ISLNK(te2->mode))) {
719 		if (!id_match ||
720 		    ((te1->mode & (S_IFLNK | S_IXUSR))) !=
721 		    (te2->mode & (S_IFLNK | S_IXUSR))) {
722 			if (diff_content)
723 				return diff_modified_blob(&te1->id, &te2->id,
724 				    f1, f2, fd1, fd2, label1, label2,
725 				    te1->mode, te2->mode, repo, cb, cb_arg);
726 			else
727 				return cb(cb_arg, NULL, NULL, NULL, NULL,
728 				    &te1->id, &te2->id, label1, label2,
729 				    te1->mode, te2->mode, repo);
730 		}
731 	}
732 
733 	if (id_match)
734 		return NULL;
735 
736 	return diff_kind_mismatch(&te1->id, &te2->id, label1, label2, repo,
737 	    cb, cb_arg);
738 }
739 
740 static const struct got_error *
741 diff_entry_new_old(struct got_tree_entry *te2,
742     struct got_tree_entry *te1, FILE *f1, FILE *f2, int fd2, const char *label2,
743     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
744     int diff_content)
745 {
746 	if (te1 != NULL) /* handled by diff_entry_old_new() */
747 		return NULL;
748 
749 	if (got_object_tree_entry_is_submodule(te2))
750 		return NULL;
751 
752 	if (S_ISDIR(te2->mode))
753 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
754 		    repo, cb, cb_arg, diff_content);
755 
756 	if (diff_content)
757 		return diff_added_blob(&te2->id, f1, f2, fd2,
758 		    label2, te2->mode, repo, cb, cb_arg);
759 
760 	return cb(cb_arg, NULL, NULL, NULL, NULL, NULL, &te2->id,
761 	    NULL, label2, 0, te2->mode, repo);
762 }
763 
764 const struct got_error *
765 got_diff_tree_compute_diffstat(void *arg, struct got_blob_object *blob1,
766     struct got_blob_object *blob2, FILE *f1, FILE *f2,
767     struct got_object_id *id1, struct got_object_id *id2,
768     const char *label1, const char *label2,
769     mode_t mode1, mode_t mode2, struct got_repository *repo)
770 {
771 	const struct got_error		*err = NULL;
772 	struct got_diffreg_result	*result = NULL;
773 	struct got_diffstat_cb_arg	*a = arg;
774 	char				*path = NULL;
775 	int				 status = GOT_STATUS_NO_CHANGE;
776 
777 	path = strdup(label2 ? label2 : label1);
778 	if (path == NULL)
779 		return got_error_from_errno("strdup");
780 
781 	if (id1 == NULL)
782 		status = GOT_STATUS_ADD;
783 	else if (id2 == NULL)
784 		status = GOT_STATUS_DELETE;
785 	else {
786 		if (got_object_id_cmp(id1, id2) != 0)
787 			status = GOT_STATUS_MODIFY;
788 		else if (mode1 != mode2)
789 			status = GOT_STATUS_MODE_CHANGE;
790 	}
791 
792 	if (f1) {
793 		err = got_opentemp_truncate(f1);
794 		if (err)
795 			goto done;
796 	}
797 	if (f2) {
798 		err = got_opentemp_truncate(f2);
799 		if (err)
800 			goto done;
801 	}
802 
803 	if (blob1) {
804 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1,
805 		    blob1);
806 		if (err)
807 			goto done;
808 	}
809 	if (blob2) {
810 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f2,
811 		    blob2);
812 		if (err)
813 			goto done;
814 	}
815 
816 	err = got_diffreg(&result, f1, f2, a->diff_algo, a->ignore_ws,
817 	    a->force_text);
818 	if (err)
819 		goto done;
820 
821 	err = get_diffstat(a, path, result->result, a->force_text, status);
822 
823 done:
824 	if (result) {
825 		const struct got_error *free_err;
826 
827 		free_err = got_diffreg_result_free(result);
828 		if (free_err && err == NULL)
829 			err = free_err;
830 	}
831 	if (err)
832 		free(path);
833 	return err;
834 }
835 
836 const struct got_error *
837 got_diff_tree_collect_changed_paths(void *arg, struct got_blob_object *blob1,
838     struct got_blob_object *blob2, FILE *f1, FILE *f2,
839     struct got_object_id *id1, struct got_object_id *id2,
840     const char *label1, const char *label2,
841     mode_t mode1, mode_t mode2, struct got_repository *repo)
842 {
843 	const struct got_error *err = NULL;
844 	struct got_pathlist_head *paths = arg;
845 	struct got_diff_changed_path *change = NULL;
846 	char *path = NULL;
847 
848 	path = strdup(label2 ? label2 : label1);
849 	if (path == NULL)
850 		return got_error_from_errno("strdup");
851 
852 	change = malloc(sizeof(*change));
853 	if (change == NULL) {
854 		err = got_error_from_errno("malloc");
855 		goto done;
856 	}
857 
858 	change->status = GOT_STATUS_NO_CHANGE;
859 	if (id1 == NULL)
860 		change->status = GOT_STATUS_ADD;
861 	else if (id2 == NULL)
862 		change->status = GOT_STATUS_DELETE;
863 	else {
864 		if (got_object_id_cmp(id1, id2) != 0)
865 			change->status = GOT_STATUS_MODIFY;
866 		else if (mode1 != mode2)
867 			change->status = GOT_STATUS_MODE_CHANGE;
868 	}
869 
870 	err = got_pathlist_append(paths, path, change);
871 done:
872 	if (err) {
873 		free(path);
874 		free(change);
875 	}
876 	return err;
877 }
878 
879 const struct got_error *
880 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
881     FILE *f1, FILE *f2, int fd1, int fd2,
882     const char *label1, const char *label2,
883     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
884     int diff_content)
885 {
886 	const struct got_error *err = NULL;
887 	struct got_tree_entry *te1 = NULL;
888 	struct got_tree_entry *te2 = NULL;
889 	char *l1 = NULL, *l2 = NULL;
890 	int tidx1 = 0, tidx2 = 0;
891 
892 	if (tree1) {
893 		te1 = got_object_tree_get_entry(tree1, 0);
894 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
895 		    te1->name) == -1)
896 			return got_error_from_errno("asprintf");
897 	}
898 	if (tree2) {
899 		te2 = got_object_tree_get_entry(tree2, 0);
900 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
901 		    te2->name) == -1) {
902 			err = got_error_from_errno("asprintf");
903 			goto done;
904 		}
905 	}
906 
907 	do {
908 		if (te1) {
909 			struct got_tree_entry *te = NULL;
910 
911 			if (tree2)
912 				te = got_object_tree_find_entry(tree2,
913 				    te1->name);
914 			if (te) {
915 				free(l2);
916 				l2 = NULL;
917 				if (te && asprintf(&l2, "%s%s%s", label2,
918 				    label2[0] ? "/" : "", te->name) == -1) {
919 					err = got_error_from_errno("asprintf");
920 					goto done;
921 				}
922 			}
923 
924 			err = diff_entry_old_new(te1, te, f1, f2, fd1, fd2,
925 			    l1, l2, repo, cb, cb_arg, diff_content);
926 			if (err)
927 				break;
928 		}
929 
930 		if (te2) {
931 			struct got_tree_entry *te = NULL;
932 
933 			if (tree1)
934 				te = got_object_tree_find_entry(tree1,
935 				    te2->name);
936 
937 			free(l2);
938 			l2 = NULL;
939 			if (te) {
940 				if (asprintf(&l2, "%s%s%s", label2,
941 				    label2[0] ? "/" : "", te->name) == -1) {
942 					err = got_error_from_errno("asprintf");
943 					goto done;
944 				}
945 			} else {
946 				if (asprintf(&l2, "%s%s%s", label2,
947 				    label2[0] ? "/" : "", te2->name) == -1) {
948 					err = got_error_from_errno("asprintf");
949 					goto done;
950 				}
951 			}
952 
953 			err = diff_entry_new_old(te2, te, f1, f2, fd2, l2,
954 			    repo, cb, cb_arg, diff_content);
955 			if (err)
956 				break;
957 		}
958 
959 		free(l1);
960 		l1 = NULL;
961 		if (te1) {
962 			tidx1++;
963 			te1 = got_object_tree_get_entry(tree1, tidx1);
964 			if (te1 &&
965 			    asprintf(&l1, "%s%s%s", label1,
966 			    label1[0] ? "/" : "", te1->name) == -1) {
967 				err = got_error_from_errno("asprintf");
968 				goto done;
969 			}
970 		}
971 
972 		free(l2);
973 		l2 = NULL;
974 		if (te2) {
975 			tidx2++;
976 			te2 = got_object_tree_get_entry(tree2, tidx2);
977 			if (te2 &&
978 			    asprintf(&l2, "%s%s%s", label2,
979 			    label2[0] ? "/" : "", te2->name) == -1) {
980 				err = got_error_from_errno("asprintf");
981 				goto done;
982 			}
983 		}
984 	} while (te1 || te2);
985 
986 done:
987 	free(l1);
988 	free(l2);
989 	return err;
990 }
991 
992 const struct got_error *
993 got_diff_objects_as_blobs(struct got_diff_line **lines, size_t *nlines,
994     FILE *f1, FILE *f2, int fd1, int fd2,
995     struct got_object_id *id1, struct got_object_id *id2,
996     const char *label1, const char *label2,
997     enum got_diff_algorithm diff_algo, int diff_context,
998     int ignore_whitespace, int force_text_diff, int show_diffstat,
999     struct got_diffstat_cb_arg *ds, struct got_repository *repo, FILE *outfile)
1000 {
1001 	const struct got_error *err;
1002 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1003 
1004 	if (id1 == NULL && id2 == NULL)
1005 		return got_error(GOT_ERR_NO_OBJ);
1006 
1007 	if (id1) {
1008 		err = got_object_open_as_blob(&blob1, repo, id1, 8192, fd1);
1009 		if (err)
1010 			goto done;
1011 	}
1012 	if (id2) {
1013 		err = got_object_open_as_blob(&blob2, repo, id2, 8192, fd2);
1014 		if (err)
1015 			goto done;
1016 	}
1017 	err = got_diff_blob(lines, nlines, blob1, blob2, f1, f2, label1, label2,
1018 	    diff_algo, diff_context, ignore_whitespace, force_text_diff,
1019 	    show_diffstat, ds, outfile);
1020 done:
1021 	if (blob1)
1022 		got_object_blob_close(blob1);
1023 	if (blob2)
1024 		got_object_blob_close(blob2);
1025 	return err;
1026 }
1027 
1028 static const struct got_error *
1029 diff_paths(struct got_tree_object *tree1, struct got_tree_object *tree2,
1030     FILE *f1, FILE *f2, int fd1, int fd2, struct got_pathlist_head *paths,
1031     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
1032 {
1033 	const struct got_error *err = NULL;
1034 	struct got_pathlist_entry *pe;
1035 	struct got_object_id *id1 = NULL, *id2 = NULL;
1036 	struct got_tree_object *subtree1 = NULL, *subtree2 = NULL;
1037 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1038 
1039 	TAILQ_FOREACH(pe, paths, entry) {
1040 		int type1 = GOT_OBJ_TYPE_ANY, type2 = GOT_OBJ_TYPE_ANY;
1041 		mode_t mode1 = 0, mode2 = 0;
1042 
1043 		free(id1);
1044 		id1 = NULL;
1045 		free(id2);
1046 		id2 = NULL;
1047 		if (subtree1) {
1048 			got_object_tree_close(subtree1);
1049 			subtree1 = NULL;
1050 		}
1051 		if (subtree2) {
1052 			got_object_tree_close(subtree2);
1053 			subtree2 = NULL;
1054 		}
1055 		if (blob1) {
1056 			got_object_blob_close(blob1);
1057 			blob1 = NULL;
1058 		}
1059 		if (blob2) {
1060 			got_object_blob_close(blob2);
1061 			blob2 = NULL;
1062 		}
1063 
1064 		err = got_object_tree_find_path(&id1, &mode1, repo, tree1,
1065 		    pe->path);
1066 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1067 			goto done;
1068 		err = got_object_tree_find_path(&id2, &mode2, repo, tree2,
1069 		    pe->path);
1070 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1071 			goto done;
1072 		if (id1 == NULL && id2 == NULL) {
1073 			err = got_error_path(pe->path, GOT_ERR_NO_TREE_ENTRY);
1074 			goto done;
1075 		}
1076 		if (id1) {
1077 			err = got_object_get_type(&type1, repo, id1);
1078 			if (err)
1079 				goto done;
1080 		}
1081 		if (id2) {
1082 			err = got_object_get_type(&type2, repo, id2);
1083 			if (err)
1084 				goto done;
1085 		}
1086 		if (type1 == GOT_OBJ_TYPE_ANY &&
1087 		    type2 == GOT_OBJ_TYPE_ANY) {
1088 			err = got_error_path(pe->path, GOT_ERR_NO_OBJ);
1089 			goto done;
1090 		} else if (type1 != GOT_OBJ_TYPE_ANY &&
1091 		    type2 != GOT_OBJ_TYPE_ANY && type1 != type2) {
1092 			err = got_error(GOT_ERR_OBJ_TYPE);
1093 			goto done;
1094 		}
1095 
1096 		if (type1 == GOT_OBJ_TYPE_BLOB ||
1097 		    type2 == GOT_OBJ_TYPE_BLOB) {
1098 			if (id1) {
1099 				err = got_object_open_as_blob(&blob1, repo,
1100 				    id1, 8192, fd1);
1101 				if (err)
1102 					goto done;
1103 			}
1104 			if (id2) {
1105 				err = got_object_open_as_blob(&blob2, repo,
1106 				    id2, 8192, fd2);
1107 				if (err)
1108 					goto done;
1109 			}
1110 			err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2,
1111 			    id1 ? pe->path : "/dev/null",
1112 			    id2 ? pe->path : "/dev/null",
1113 			    mode1, mode2, repo);
1114 			if (err)
1115 				goto done;
1116 		} else if (type1 == GOT_OBJ_TYPE_TREE ||
1117 		    type2 == GOT_OBJ_TYPE_TREE) {
1118 			if (id1) {
1119 				err = got_object_open_as_tree(&subtree1, repo,
1120 				    id1);
1121 				if (err)
1122 					goto done;
1123 			}
1124 			if (id2) {
1125 				err = got_object_open_as_tree(&subtree2, repo,
1126 				    id2);
1127 				if (err)
1128 					goto done;
1129 			}
1130 			err = got_diff_tree(subtree1, subtree2, f1, f2,
1131 			    fd1, fd2,
1132 			    id1 ? pe->path : "/dev/null",
1133 			    id2 ? pe->path : "/dev/null",
1134 			    repo, cb, cb_arg, 1);
1135 			if (err)
1136 				goto done;
1137 		} else {
1138 			err = got_error(GOT_ERR_OBJ_TYPE);
1139 			goto done;
1140 		}
1141 	}
1142 done:
1143 	free(id1);
1144 	free(id2);
1145 	if (subtree1)
1146 		got_object_tree_close(subtree1);
1147 	if (subtree2)
1148 		got_object_tree_close(subtree2);
1149 	if (blob1)
1150 		got_object_blob_close(blob1);
1151 	if (blob2)
1152 		got_object_blob_close(blob2);
1153 	return err;
1154 }
1155 
1156 static const struct got_error *
1157 show_object_id(struct got_diff_line **lines, size_t *nlines,
1158     const char *obj_typestr, int ch, const char *id_str, FILE *outfile)
1159 {
1160 	const struct got_error *err;
1161 	int n;
1162 	off_t outoff = 0;
1163 
1164 	n = fprintf(outfile, "%s %c %s\n", obj_typestr, ch, id_str);
1165 	if (n < 0)
1166 		return got_error_from_errno("fprintf");
1167 
1168 	if (lines != NULL && *lines != NULL) {
1169 		if (*nlines == 0) {
1170 			err = add_line_metadata(lines, nlines, 0,
1171 			    GOT_DIFF_LINE_META);
1172 			if (err)
1173 				return err;
1174 		} else
1175 			outoff = (*lines)[*nlines - 1].offset;
1176 
1177 		outoff += n;
1178 		err = add_line_metadata(lines, nlines, outoff,
1179 		    GOT_DIFF_LINE_META);
1180 		if (err)
1181 			return err;
1182 	}
1183 
1184 	return NULL;
1185 }
1186 
1187 static const struct got_error *
1188 diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1189     FILE *f1, FILE *f2, int fd1, int fd2,
1190     struct got_object_id *id1, struct got_object_id *id2,
1191     struct got_pathlist_head *paths, const char *label1, const char *label2,
1192     int diff_context, int ignore_whitespace, int force_text_diff,
1193     int show_diffstat, struct got_diffstat_cb_arg *dsa,
1194     struct got_repository *repo, FILE *outfile,
1195     enum got_diff_algorithm diff_algo)
1196 {
1197 	const struct got_error *err;
1198 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1199 	struct got_diff_blob_output_unidiff_arg arg;
1200 	int want_linemeta = (lines != NULL && *lines != NULL);
1201 
1202 	if (id1 == NULL && id2 == NULL)
1203 		return got_error(GOT_ERR_NO_OBJ);
1204 
1205 	if (id1) {
1206 		err = got_object_open_as_tree(&tree1, repo, id1);
1207 		if (err)
1208 			goto done;
1209 	}
1210 	if (id2) {
1211 		err = got_object_open_as_tree(&tree2, repo, id2);
1212 		if (err)
1213 			goto done;
1214 	}
1215 
1216 	arg.diff_algo = diff_algo;
1217 	arg.diff_context = diff_context;
1218 	arg.ignore_whitespace = ignore_whitespace;
1219 	arg.force_text_diff = force_text_diff;
1220 	arg.show_diffstat = show_diffstat;
1221 	arg.diffstat = dsa;
1222 	arg.outfile = outfile;
1223 	if (want_linemeta) {
1224 		arg.lines = *lines;
1225 		arg.nlines = *nlines;
1226 	} else {
1227 		arg.lines = NULL;
1228 		arg.nlines = 0;
1229 	}
1230 	if (paths == NULL || TAILQ_EMPTY(paths))
1231 		err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2, label1,
1232 		    label2, repo, got_diff_blob_output_unidiff, &arg, 1);
1233 	else
1234 		err = diff_paths(tree1, tree2, f1, f2, fd1, fd2, paths, repo,
1235 		    got_diff_blob_output_unidiff, &arg);
1236 	if (want_linemeta) {
1237 		*lines = arg.lines; /* was likely re-allocated */
1238 		*nlines = arg.nlines;
1239 	}
1240 done:
1241 	if (tree1)
1242 		got_object_tree_close(tree1);
1243 	if (tree2)
1244 		got_object_tree_close(tree2);
1245 	return err;
1246 }
1247 
1248 const struct got_error *
1249 got_diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1250     FILE *f1, FILE *f2, int fd1, int fd2,
1251     struct got_object_id *id1, struct got_object_id *id2,
1252     struct got_pathlist_head *paths, const char *label1, const char *label2,
1253     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
1254     int force_text_diff, int show_diffstat, struct got_diffstat_cb_arg *dsa,
1255     struct got_repository *repo, FILE *outfile)
1256 {
1257 	const struct got_error *err;
1258 	char *idstr = NULL;
1259 
1260 	if (id1 == NULL && id2 == NULL)
1261 		return got_error(GOT_ERR_NO_OBJ);
1262 
1263 	if (id1) {
1264 		err = got_object_id_str(&idstr, id1);
1265 		if (err)
1266 			goto done;
1267 		err = show_object_id(lines, nlines, "tree", '-', idstr, outfile);
1268 		if (err)
1269 			goto done;
1270 		free(idstr);
1271 		idstr = NULL;
1272 	} else {
1273 		err = show_object_id(lines, nlines, "tree", '-', "/dev/null",
1274 		    outfile);
1275 		if (err)
1276 			goto done;
1277 	}
1278 
1279 	if (id2) {
1280 		err = got_object_id_str(&idstr, id2);
1281 		if (err)
1282 			goto done;
1283 		err = show_object_id(lines, nlines, "tree", '+', idstr, outfile);
1284 		if (err)
1285 			goto done;
1286 		free(idstr);
1287 		idstr = NULL;
1288 	} else {
1289 		err = show_object_id(lines, nlines, "tree", '+', "/dev/null",
1290 		    outfile);
1291 		if (err)
1292 			goto done;
1293 	}
1294 
1295 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2, id1, id2,
1296 	    paths, label1, label2, diff_context, ignore_whitespace,
1297 	    force_text_diff, show_diffstat, dsa, repo, outfile, diff_algo);
1298 done:
1299 	free(idstr);
1300 	return err;
1301 }
1302 
1303 const struct got_error *
1304 got_diff_objects_as_commits(struct got_diff_line **lines, size_t *nlines,
1305     FILE *f1, FILE *f2, int fd1, int fd2,
1306     struct got_object_id *id1, struct got_object_id *id2,
1307     struct got_pathlist_head *paths, enum got_diff_algorithm diff_algo,
1308     int diff_context, int ignore_whitespace, int force_text_diff,
1309     int show_diffstat, struct got_diffstat_cb_arg *dsa,
1310     struct got_repository *repo, FILE *outfile)
1311 {
1312 	const struct got_error *err;
1313 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
1314 	char *idstr = NULL;
1315 
1316 	if (id2 == NULL)
1317 		return got_error(GOT_ERR_NO_OBJ);
1318 
1319 	if (id1) {
1320 		err = got_object_open_as_commit(&commit1, repo, id1);
1321 		if (err)
1322 			goto done;
1323 		err = got_object_id_str(&idstr, id1);
1324 		if (err)
1325 			goto done;
1326 		err = show_object_id(lines, nlines, "commit", '-', idstr,
1327 		    outfile);
1328 		if (err)
1329 			goto done;
1330 		free(idstr);
1331 		idstr = NULL;
1332 	} else {
1333 		err = show_object_id(lines, nlines, "commit", '-', "/dev/null",
1334 		    outfile);
1335 		if (err)
1336 			goto done;
1337 	}
1338 
1339 	err = got_object_open_as_commit(&commit2, repo, id2);
1340 	if (err)
1341 		goto done;
1342 
1343 	err = got_object_id_str(&idstr, id2);
1344 	if (err)
1345 		goto done;
1346 	err = show_object_id(lines, nlines, "commit", '+', idstr, outfile);
1347 	if (err)
1348 		goto done;
1349 
1350 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2,
1351 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
1352 	    got_object_commit_get_tree_id(commit2), paths, "", "",
1353 	    diff_context, ignore_whitespace, force_text_diff, show_diffstat,
1354 	    dsa, repo, outfile, diff_algo);
1355 done:
1356 	if (commit1)
1357 		got_object_commit_close(commit1);
1358 	if (commit2)
1359 		got_object_commit_close(commit2);
1360 	free(idstr);
1361 	return err;
1362 }
1363 
1364 const struct got_error *
1365 got_diff_files(struct got_diffreg_result **resultp,
1366     FILE *f1, int f1_exists, const char *label1, FILE *f2, int f2_exists,
1367     const char *label2, int diff_context, int ignore_whitespace,
1368     int force_text_diff, FILE *outfile, enum got_diff_algorithm diff_algo)
1369 {
1370 	const struct got_error *err = NULL;
1371 	struct got_diffreg_result *diffreg_result = NULL;
1372 
1373 	if (resultp)
1374 		*resultp = NULL;
1375 
1376 	if (outfile) {
1377 		fprintf(outfile, "file - %s\n",
1378 		    f1_exists ? label1 : "/dev/null");
1379 		fprintf(outfile, "file + %s\n",
1380 		    f2_exists ? label2 : "/dev/null");
1381 	}
1382 
1383 	err = got_diffreg(&diffreg_result, f1, f2, diff_algo,
1384 	    ignore_whitespace, force_text_diff);
1385 	if (err)
1386 		goto done;
1387 
1388 	if (outfile) {
1389 		err = got_diffreg_output(NULL, NULL, diffreg_result,
1390 		    f1_exists, f2_exists, label1, label2,
1391 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
1392 		if (err)
1393 			goto done;
1394 	}
1395 
1396 done:
1397 	if (resultp && err == NULL)
1398 		*resultp = diffreg_result;
1399 	else if (diffreg_result) {
1400 		const struct got_error *free_err;
1401 
1402 		free_err = got_diffreg_result_free(diffreg_result);
1403 		if (free_err && err == NULL)
1404 			err = free_err;
1405 	}
1406 
1407 	return err;
1408 }