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 <sha2.h>
26 #include <zlib.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     struct got_diffstat_cb_arg *diffstat, FILE *outfile,
137     enum got_diff_algorithm diff_algo)
138 {
139 	const struct got_error *err = NULL, *free_err;
140 	char hex1[GOT_OBJECT_ID_HEX_MAXLEN];
141 	char hex2[GOT_OBJECT_ID_HEX_MAXLEN];
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 (diffstat) {
247 		char	*path = NULL;
248 		int	 status = GOT_STATUS_NO_CHANGE;
249 
250 		if (blob1 == NULL)
251 			status = GOT_STATUS_ADD;
252 		else if (blob2 == NULL)
253 			status = GOT_STATUS_DELETE;
254 		else {
255 			if (strcmp(idstr1, idstr2) != 0)
256 				status = GOT_STATUS_MODIFY;
257 			else if (mode1 != mode2)
258 				status = GOT_STATUS_MODE_CHANGE;
259 		}
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(diffstat, path, result->result,
281 		    force_text_diff, 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->diffstat, a->outfile,
324 	    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,
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, 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, struct got_diffstat_cb_arg *diffstat, FILE *outfile)
346 {
347 	const struct got_error *err = NULL, *free_err;
348 	char hex1[GOT_OBJECT_ID_HEX_MAXLEN];
349 	const char *idstr1 = NULL;
350 	struct got_diffreg_result *result = NULL;
351 
352 	if (resultp)
353 		*resultp = NULL;
354 
355 	if (blob1)
356 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
357 	else
358 		idstr1 = "/dev/null";
359 
360 	if (outfile) {
361 		char	*mode = NULL;
362 
363 		/* display file mode for new added files only */
364 		if (f2_exists && blob1 == NULL) {
365 			int mmask = (S_IRWXU | S_IRWXG | S_IRWXO);
366 
367 			if (S_ISLNK(sb2->st_mode))
368 				mmask = S_IFLNK;
369 			if (asprintf(&mode, " (mode %o)",
370 			    sb2->st_mode & mmask) == -1)
371 				return got_error_from_errno("asprintf");
372 		}
373 		fprintf(outfile, "blob - %s\n", label1 ? label1 : idstr1);
374 		fprintf(outfile, "file + %s%s\n",
375 		    f2_exists ? label2 : "/dev/null", mode ? mode : "");
376 		free(mode);
377 	}
378 
379 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
380 	    force_text_diff);
381 	if (err) {
382 		char msg[GOT_ERR_MAX_MSG_SIZE];
383 		if (snprintf(msg, sizeof(msg), "%s vs %s: %s",
384 		             label1 ? label1 : idstr1,
385 		             f2_exists ? label2 : "/dev/null", err->msg) >= 0) {
386 			err = got_error_msg(err->code, msg);
387 		}
388 		goto done;
389 	}
390 
391 	if (outfile) {
392 		err = got_diffreg_output(NULL, NULL, result,
393 		    blob1 != NULL, f2_exists,
394 		    label2, /* show local file's path, not a blob ID */
395 		    label2, GOT_DIFF_OUTPUT_UNIDIFF,
396 		    diff_context, outfile);
397 		if (err)
398 			goto done;
399 	}
400 
401 	if (diffstat) {
402 		char	*path = NULL;
403 		int	 status = GOT_STATUS_NO_CHANGE;
404 
405 		/*
406 		 * Ignore 'm'ode status change: if there's no accompanying
407 		 * content change, there'll be no diffstat, and if there
408 		 * are actual changes, 'M'odified takes precedence.
409 		 */
410 		if (blob1 == NULL)
411 			status = GOT_STATUS_ADD;
412 		else if (!f2_exists)
413 			status = GOT_STATUS_DELETE;
414 		else
415 			status = GOT_STATUS_MODIFY;
416 
417 		if (label2 != NULL &&
418 		    (status != GOT_STATUS_DELETE || label1 == NULL))
419 			path = strdup(label2);
420 		else
421 			path = strdup(label1);
422 		if (path == NULL) {
423 			err = got_error_from_errno("strdup");
424 			goto done;
425 		}
426 
427 		err = get_diffstat(diffstat, path, result->result,
428 		    force_text_diff, status);
429 		if (err) {
430 			free(path);
431 			goto done;
432 		}
433 	}
434 
435 done:
436 	if (resultp && err == NULL)
437 		*resultp = result;
438 	else if (result) {
439 		free_err = got_diffreg_result_free(result);
440 		if (free_err && err == NULL)
441 			err = free_err;
442 	}
443 	return err;
444 }
445 
446 const struct got_error *
447 got_diff_blob_file(struct got_blob_object *blob1, FILE *f1, off_t size1,
448     const char *label1, FILE *f2, int f2_exists, struct stat *sb2,
449     const char *label2, enum got_diff_algorithm diff_algo, int diff_context,
450     int ignore_whitespace, int force_text_diff,
451     struct got_diffstat_cb_arg *ds, FILE *outfile)
452 {
453 	return diff_blob_file(NULL, blob1, f1, size1, label1, f2, f2_exists,
454 	    sb2, label2, diff_algo, diff_context, ignore_whitespace,
455 	    force_text_diff, ds, outfile);
456 }
457 
458 static const struct got_error *
459 diff_added_blob(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
460     const char *label, mode_t mode, struct got_repository *repo,
461     got_diff_blob_cb cb, void *cb_arg)
462 {
463 	const struct got_error *err;
464 	struct got_blob_object  *blob = NULL;
465 	struct got_object *obj = NULL;
466 
467 	err = got_object_open(&obj, repo, id);
468 	if (err)
469 		return err;
470 
471 	err = got_object_blob_open(&blob, repo, obj, 8192, fd2);
472 	if (err)
473 		goto done;
474 	err = cb(cb_arg, NULL, blob, f1, f2, NULL, id,
475 	    NULL, label, 0, mode, repo);
476 done:
477 	got_object_close(obj);
478 	if (blob)
479 		got_object_blob_close(blob);
480 	return err;
481 }
482 
483 static const struct got_error *
484 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
485     FILE *f1, FILE *f2, int fd1, int fd2,
486     const char *label1, const char *label2,
487     mode_t mode1, mode_t mode2, struct got_repository *repo,
488     got_diff_blob_cb cb, void *cb_arg)
489 {
490 	const struct got_error *err;
491 	struct got_object *obj1 = NULL;
492 	struct got_object *obj2 = NULL;
493 	struct got_blob_object *blob1 = NULL;
494 	struct got_blob_object *blob2 = NULL;
495 
496 	err = got_object_open(&obj1, repo, id1);
497 	if (err)
498 		return err;
499 
500 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
501 		err = got_error(GOT_ERR_OBJ_TYPE);
502 		goto done;
503 	}
504 
505 	err = got_object_open(&obj2, repo, id2);
506 	if (err)
507 		goto done;
508 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
509 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
510 		goto done;
511 	}
512 
513 	err = got_object_blob_open(&blob1, repo, obj1, 8192, fd1);
514 	if (err)
515 		goto done;
516 
517 	err = got_object_blob_open(&blob2, repo, obj2, 8192, fd2);
518 	if (err)
519 		goto done;
520 
521 	err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2, label1, label2,
522 	    mode1, mode2, repo);
523 done:
524 	if (obj1)
525 		got_object_close(obj1);
526 	if (obj2)
527 		got_object_close(obj2);
528 	if (blob1)
529 		got_object_blob_close(blob1);
530 	if (blob2)
531 		got_object_blob_close(blob2);
532 	return err;
533 }
534 
535 static const struct got_error *
536 diff_deleted_blob(struct got_object_id *id, FILE *f1, int fd1,
537    FILE *f2, const char *label, mode_t mode, struct got_repository *repo,
538    got_diff_blob_cb cb, void *cb_arg)
539 {
540 	const struct got_error *err;
541 	struct got_blob_object  *blob = NULL;
542 	struct got_object *obj = NULL;
543 
544 	err = got_object_open(&obj, repo, id);
545 	if (err)
546 		return err;
547 
548 	err = got_object_blob_open(&blob, repo, obj, 8192, fd1);
549 	if (err)
550 		goto done;
551 	err = cb(cb_arg, blob, NULL, f1, f2, id, NULL, label, NULL,
552 	    mode, 0, repo);
553 done:
554 	got_object_close(obj);
555 	if (blob)
556 		got_object_blob_close(blob);
557 	return err;
558 }
559 
560 static const struct got_error *
561 diff_added_tree(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
562     const char *label, struct got_repository *repo, got_diff_blob_cb cb,
563     void *cb_arg, int diff_content)
564 {
565 	const struct got_error *err = NULL;
566 	struct got_object *treeobj = NULL;
567 	struct got_tree_object *tree = NULL;
568 
569 	err = got_object_open(&treeobj, repo, id);
570 	if (err)
571 		goto done;
572 
573 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
574 		err = got_error(GOT_ERR_OBJ_TYPE);
575 		goto done;
576 	}
577 
578 	err = got_object_tree_open(&tree, repo, treeobj);
579 	if (err)
580 		goto done;
581 
582 	err = got_diff_tree(NULL, tree, f1, f2, -1, fd2, NULL, label,
583 	    repo, cb, cb_arg, diff_content);
584 done:
585 	if (tree)
586 		got_object_tree_close(tree);
587 	if (treeobj)
588 		got_object_close(treeobj);
589 	return err;
590 }
591 
592 static const struct got_error *
593 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
594     FILE *f1, FILE *f2, int fd1, int fd2,
595     const char *label1, const char *label2,
596     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
597     int diff_content)
598 {
599 	const struct got_error *err;
600 	struct got_object *treeobj1 = NULL;
601 	struct got_object *treeobj2 = NULL;
602 	struct got_tree_object *tree1 = NULL;
603 	struct got_tree_object *tree2 = NULL;
604 
605 	err = got_object_open(&treeobj1, repo, id1);
606 	if (err)
607 		goto done;
608 
609 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
610 		err = got_error(GOT_ERR_OBJ_TYPE);
611 		goto done;
612 	}
613 
614 	err = got_object_open(&treeobj2, repo, id2);
615 	if (err)
616 		goto done;
617 
618 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
619 		err = got_error(GOT_ERR_OBJ_TYPE);
620 		goto done;
621 	}
622 
623 	err = got_object_tree_open(&tree1, repo, treeobj1);
624 	if (err)
625 		goto done;
626 
627 	err = got_object_tree_open(&tree2, repo, treeobj2);
628 	if (err)
629 		goto done;
630 
631 	err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2,
632 	    label1, label2, repo, cb, cb_arg, diff_content);
633 
634 done:
635 	if (tree1)
636 		got_object_tree_close(tree1);
637 	if (tree2)
638 		got_object_tree_close(tree2);
639 	if (treeobj1)
640 		got_object_close(treeobj1);
641 	if (treeobj2)
642 		got_object_close(treeobj2);
643 	return err;
644 }
645 
646 static const struct got_error *
647 diff_deleted_tree(struct got_object_id *id, FILE *f1, int fd1,
648     FILE *f2, const char *label, struct got_repository *repo,
649     got_diff_blob_cb cb, void *cb_arg, int diff_content)
650 {
651 	const struct got_error *err;
652 	struct got_object *treeobj = NULL;
653 	struct got_tree_object *tree = NULL;
654 
655 	err = got_object_open(&treeobj, repo, id);
656 	if (err)
657 		goto done;
658 
659 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
660 		err = got_error(GOT_ERR_OBJ_TYPE);
661 		goto done;
662 	}
663 
664 	err = got_object_tree_open(&tree, repo, treeobj);
665 	if (err)
666 		goto done;
667 
668 	err = got_diff_tree(tree, NULL, f1, f2, fd1, -1, label, NULL,
669 	    repo, cb, cb_arg, diff_content);
670 done:
671 	if (tree)
672 		got_object_tree_close(tree);
673 	if (treeobj)
674 		got_object_close(treeobj);
675 	return err;
676 }
677 
678 static const struct got_error *
679 diff_kind_mismatch(struct got_tree_entry *te1, struct got_tree_entry *te2,
680     FILE *f1, FILE *f2, int fd1, int fd2,
681     const char *label1, const char *label2, struct got_repository *repo,
682     got_diff_blob_cb cb, void *cb_arg, int diff_content)
683 {
684 	const struct got_error *err = NULL;
685 
686 	/* 
687 	 * Handle files changing into directories and vice-versa.
688 	 * Disregard edge cases with FIFOs, device nodes, etc for now.
689 	 */
690 	if (!S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
691 		if (S_ISREG(te1->mode)) {
692 			if (diff_content) {
693 				err = diff_deleted_blob(&te1->id, f1, fd1,
694 				    f2, label1, te1->mode, repo, cb, cb_arg);
695 			} else {
696 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
697 				    &te1->id, NULL, label1, NULL,
698 				    te1->mode, 0, repo);
699 			}
700 			if (err)
701 				return err;
702 		}
703 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
704 		    repo, cb, cb_arg, diff_content);
705 	} else if (S_ISDIR(te1->mode) && !S_ISDIR(te2->mode)) {
706 		err = diff_deleted_tree(&te1->id, f1, fd1, f2,
707 		    label1, repo, cb, cb_arg, diff_content);
708 		if (err)
709 			return err;
710 		if (S_ISREG(te2->mode)) {
711 			if (diff_content) {
712 				err = diff_added_blob(&te2->id, f1, f2, fd2,
713 				    label2, te2->mode, repo, cb, cb_arg);
714 			} else {
715 				err = cb(cb_arg, NULL, NULL, NULL, NULL, NULL,
716 				    &te2->id, NULL, label2, 0, te2->mode, repo);
717 			}
718 			if (err)
719 				return err;
720 		}
721 	}
722 
723 	return NULL;
724 }
725 
726 static const struct got_error *
727 diff_entry_old_new(struct got_tree_entry *te1, struct got_tree_entry *te2,
728     FILE *f1, FILE *f2, int fd1, int fd2,
729     const char *label1, const char *label2,
730     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
731     int diff_content)
732 {
733 	const struct got_error *err = NULL;
734 	int id_match;
735 
736 	if (got_object_tree_entry_is_submodule(te1))
737 		return NULL;
738 
739 	if (te2 == NULL) {
740 		if (S_ISDIR(te1->mode))
741 			err = diff_deleted_tree(&te1->id, f1, fd1, f2,
742 			    label1, repo, cb, cb_arg, diff_content);
743 		else {
744 			if (diff_content)
745 				err = diff_deleted_blob(&te1->id, f1, fd1,
746 				    f2, label1, te1->mode, repo, cb, cb_arg);
747 			else
748 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
749 				    &te1->id, NULL, label1, NULL,
750 				    te1->mode, 0, repo);
751 		}
752 		return err;
753 	} else if (got_object_tree_entry_is_submodule(te2))
754 		return NULL;
755 
756 	id_match = (got_object_id_cmp(&te1->id, &te2->id) == 0);
757 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
758 		if (!id_match)
759 			return diff_modified_tree(&te1->id, &te2->id, f1, f2,
760 			    fd1, fd2, label1, label2, repo, cb, cb_arg,
761 			    diff_content);
762 	} else if ((S_ISREG(te1->mode) || S_ISLNK(te1->mode)) &&
763 	    (S_ISREG(te2->mode) || S_ISLNK(te2->mode))) {
764 		if (!id_match ||
765 		    ((te1->mode & (S_IFLNK | S_IXUSR))) !=
766 		    (te2->mode & (S_IFLNK | S_IXUSR))) {
767 			if (diff_content)
768 				return diff_modified_blob(&te1->id, &te2->id,
769 				    f1, f2, fd1, fd2, label1, label2,
770 				    te1->mode, te2->mode, repo, cb, cb_arg);
771 			else
772 				return cb(cb_arg, NULL, NULL, NULL, NULL,
773 				    &te1->id, &te2->id, label1, label2,
774 				    te1->mode, te2->mode, repo);
775 		}
776 	}
777 
778 	if (id_match)
779 		return NULL;
780 
781 	return diff_kind_mismatch(te1, te2, f1, f2, fd1, fd2,
782 	    label1, label2, repo, cb, cb_arg, diff_content);
783 }
784 
785 static const struct got_error *
786 diff_entry_new_old(struct got_tree_entry *te2,
787     struct got_tree_entry *te1, FILE *f1, FILE *f2, int fd2, const char *label2,
788     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
789     int diff_content)
790 {
791 	if (te1 != NULL) /* handled by diff_entry_old_new() */
792 		return NULL;
793 
794 	if (got_object_tree_entry_is_submodule(te2))
795 		return NULL;
796 
797 	if (S_ISDIR(te2->mode))
798 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
799 		    repo, cb, cb_arg, diff_content);
800 
801 	if (diff_content)
802 		return diff_added_blob(&te2->id, f1, f2, fd2,
803 		    label2, te2->mode, repo, cb, cb_arg);
804 
805 	return cb(cb_arg, NULL, NULL, NULL, NULL, NULL, &te2->id,
806 	    NULL, label2, 0, te2->mode, repo);
807 }
808 
809 const struct got_error *
810 got_diff_tree_compute_diffstat(void *arg, struct got_blob_object *blob1,
811     struct got_blob_object *blob2, FILE *f1, FILE *f2,
812     struct got_object_id *id1, struct got_object_id *id2,
813     const char *label1, const char *label2,
814     mode_t mode1, mode_t mode2, struct got_repository *repo)
815 {
816 	const struct got_error		*err = NULL;
817 	struct got_diffreg_result	*result = NULL;
818 	struct got_diffstat_cb_arg	*a = arg;
819 	char				*path = NULL;
820 	int				 status = GOT_STATUS_NO_CHANGE;
821 
822 	path = strdup(label2 ? label2 : label1);
823 	if (path == NULL)
824 		return got_error_from_errno("strdup");
825 
826 	if (id1 == NULL)
827 		status = GOT_STATUS_ADD;
828 	else if (id2 == NULL)
829 		status = GOT_STATUS_DELETE;
830 	else {
831 		if (got_object_id_cmp(id1, id2) != 0)
832 			status = GOT_STATUS_MODIFY;
833 		else if (mode1 != mode2)
834 			status = GOT_STATUS_MODE_CHANGE;
835 	}
836 
837 	if (f1) {
838 		err = got_opentemp_truncate(f1);
839 		if (err)
840 			goto done;
841 	}
842 	if (f2) {
843 		err = got_opentemp_truncate(f2);
844 		if (err)
845 			goto done;
846 	}
847 
848 	if (blob1) {
849 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1,
850 		    blob1);
851 		if (err)
852 			goto done;
853 	}
854 	if (blob2) {
855 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f2,
856 		    blob2);
857 		if (err)
858 			goto done;
859 	}
860 
861 	err = got_diffreg(&result, f1, f2, a->diff_algo, a->ignore_ws,
862 	    a->force_text);
863 	if (err)
864 		goto done;
865 
866 	err = get_diffstat(a, path, result->result, a->force_text, status);
867 
868 done:
869 	if (result) {
870 		const struct got_error *free_err;
871 
872 		free_err = got_diffreg_result_free(result);
873 		if (free_err && err == NULL)
874 			err = free_err;
875 	}
876 	if (err)
877 		free(path);
878 	return err;
879 }
880 
881 const struct got_error *
882 got_diff_tree_collect_changed_paths(void *arg, struct got_blob_object *blob1,
883     struct got_blob_object *blob2, FILE *f1, FILE *f2,
884     struct got_object_id *id1, struct got_object_id *id2,
885     const char *label1, const char *label2,
886     mode_t mode1, mode_t mode2, struct got_repository *repo)
887 {
888 	const struct got_error *err = NULL;
889 	struct got_pathlist_head *paths = arg;
890 	struct got_diff_changed_path *change = NULL;
891 	char *path = NULL;
892 
893 	path = strdup(label2 ? label2 : label1);
894 	if (path == NULL)
895 		return got_error_from_errno("strdup");
896 
897 	change = malloc(sizeof(*change));
898 	if (change == NULL) {
899 		err = got_error_from_errno("malloc");
900 		goto done;
901 	}
902 
903 	change->status = GOT_STATUS_NO_CHANGE;
904 	if (id1 == NULL)
905 		change->status = GOT_STATUS_ADD;
906 	else if (id2 == NULL)
907 		change->status = GOT_STATUS_DELETE;
908 	else {
909 		if (got_object_id_cmp(id1, id2) != 0)
910 			change->status = GOT_STATUS_MODIFY;
911 		else if (mode1 != mode2)
912 			change->status = GOT_STATUS_MODE_CHANGE;
913 	}
914 
915 	err = got_pathlist_append(paths, path, change);
916 done:
917 	if (err) {
918 		free(path);
919 		free(change);
920 	}
921 	return err;
922 }
923 
924 const struct got_error *
925 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
926     FILE *f1, FILE *f2, int fd1, int fd2,
927     const char *label1, const char *label2,
928     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
929     int diff_content)
930 {
931 	const struct got_error *err = NULL;
932 	struct got_tree_entry *te1 = NULL;
933 	struct got_tree_entry *te2 = NULL;
934 	char *l1 = NULL, *l2 = NULL;
935 	int tidx1 = 0, tidx2 = 0;
936 
937 	if (tree1) {
938 		te1 = got_object_tree_get_entry(tree1, 0);
939 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
940 		    te1->name) == -1)
941 			return got_error_from_errno("asprintf");
942 	}
943 	if (tree2) {
944 		te2 = got_object_tree_get_entry(tree2, 0);
945 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
946 		    te2->name) == -1) {
947 			err = got_error_from_errno("asprintf");
948 			goto done;
949 		}
950 	}
951 
952 	do {
953 		if (te1) {
954 			struct got_tree_entry *te = NULL;
955 
956 			if (tree2)
957 				te = got_object_tree_find_entry(tree2,
958 				    te1->name);
959 			if (te) {
960 				free(l2);
961 				l2 = NULL;
962 				if (te && asprintf(&l2, "%s%s%s", label2,
963 				    label2[0] ? "/" : "", te->name) == -1) {
964 					err = got_error_from_errno("asprintf");
965 					goto done;
966 				}
967 			}
968 
969 			err = diff_entry_old_new(te1, te, f1, f2, fd1, fd2,
970 			    l1, l2, repo, cb, cb_arg, diff_content);
971 			if (err)
972 				break;
973 		}
974 
975 		if (te2) {
976 			struct got_tree_entry *te = NULL;
977 
978 			if (tree1)
979 				te = got_object_tree_find_entry(tree1,
980 				    te2->name);
981 
982 			free(l2);
983 			l2 = NULL;
984 			if (te) {
985 				if (asprintf(&l2, "%s%s%s", label2,
986 				    label2[0] ? "/" : "", te->name) == -1) {
987 					err = got_error_from_errno("asprintf");
988 					goto done;
989 				}
990 			} else {
991 				if (asprintf(&l2, "%s%s%s", label2,
992 				    label2[0] ? "/" : "", te2->name) == -1) {
993 					err = got_error_from_errno("asprintf");
994 					goto done;
995 				}
996 			}
997 
998 			err = diff_entry_new_old(te2, te, f1, f2, fd2, l2,
999 			    repo, cb, cb_arg, diff_content);
1000 			if (err)
1001 				break;
1002 		}
1003 
1004 		free(l1);
1005 		l1 = NULL;
1006 		if (te1) {
1007 			tidx1++;
1008 			te1 = got_object_tree_get_entry(tree1, tidx1);
1009 			if (te1 &&
1010 			    asprintf(&l1, "%s%s%s", label1,
1011 			    label1[0] ? "/" : "", te1->name) == -1) {
1012 				err = got_error_from_errno("asprintf");
1013 				goto done;
1014 			}
1015 		}
1016 
1017 		free(l2);
1018 		l2 = NULL;
1019 		if (te2) {
1020 			tidx2++;
1021 			te2 = got_object_tree_get_entry(tree2, tidx2);
1022 			if (te2 &&
1023 			    asprintf(&l2, "%s%s%s", label2,
1024 			    label2[0] ? "/" : "", te2->name) == -1) {
1025 				err = got_error_from_errno("asprintf");
1026 				goto done;
1027 			}
1028 		}
1029 	} while (te1 || te2);
1030 
1031 done:
1032 	free(l1);
1033 	free(l2);
1034 	return err;
1035 }
1036 
1037 const struct got_error *
1038 got_diff_objects_as_blobs(struct got_diff_line **lines, size_t *nlines,
1039     FILE *f1, FILE *f2, int fd1, int fd2,
1040     struct got_object_id *id1, struct got_object_id *id2,
1041     const char *label1, const char *label2,
1042     enum got_diff_algorithm diff_algo, int diff_context,
1043     int ignore_whitespace, int force_text_diff, struct got_diffstat_cb_arg *ds,
1044     struct got_repository *repo, FILE *outfile)
1045 {
1046 	const struct got_error *err;
1047 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1048 
1049 	if (id1 == NULL && id2 == NULL)
1050 		return got_error(GOT_ERR_NO_OBJ);
1051 
1052 	if (id1) {
1053 		err = got_object_open_as_blob(&blob1, repo, id1, 8192, fd1);
1054 		if (err)
1055 			goto done;
1056 	}
1057 	if (id2) {
1058 		err = got_object_open_as_blob(&blob2, repo, id2, 8192, fd2);
1059 		if (err)
1060 			goto done;
1061 	}
1062 	err = got_diff_blob(lines, nlines, blob1, blob2, f1, f2, label1, label2,
1063 	    diff_algo, diff_context, ignore_whitespace, force_text_diff,
1064 	    ds, outfile);
1065 done:
1066 	if (blob1)
1067 		got_object_blob_close(blob1);
1068 	if (blob2)
1069 		got_object_blob_close(blob2);
1070 	return err;
1071 }
1072 
1073 static const struct got_error *
1074 diff_paths(struct got_tree_object *tree1, struct got_tree_object *tree2,
1075     FILE *f1, FILE *f2, int fd1, int fd2, struct got_pathlist_head *paths,
1076     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
1077 {
1078 	const struct got_error *err = NULL;
1079 	struct got_pathlist_entry *pe;
1080 	struct got_object_id *id1 = NULL, *id2 = NULL;
1081 	struct got_tree_object *subtree1 = NULL, *subtree2 = NULL;
1082 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1083 
1084 	TAILQ_FOREACH(pe, paths, entry) {
1085 		int type1 = GOT_OBJ_TYPE_ANY, type2 = GOT_OBJ_TYPE_ANY;
1086 		mode_t mode1 = 0, mode2 = 0;
1087 
1088 		free(id1);
1089 		id1 = NULL;
1090 		free(id2);
1091 		id2 = NULL;
1092 		if (subtree1) {
1093 			got_object_tree_close(subtree1);
1094 			subtree1 = NULL;
1095 		}
1096 		if (subtree2) {
1097 			got_object_tree_close(subtree2);
1098 			subtree2 = NULL;
1099 		}
1100 		if (blob1) {
1101 			got_object_blob_close(blob1);
1102 			blob1 = NULL;
1103 		}
1104 		if (blob2) {
1105 			got_object_blob_close(blob2);
1106 			blob2 = NULL;
1107 		}
1108 		if (tree1) {
1109 			err = got_object_tree_find_path(&id1, &mode1, repo,
1110 			    tree1, pe->path);
1111 			if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1112 				goto done;
1113 		}
1114 		if (tree2) {
1115 			err = got_object_tree_find_path(&id2, &mode2, repo,
1116 			    tree2, pe->path);
1117 			if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1118 				goto done;
1119 		}
1120 		if (id1 == NULL && id2 == NULL) {
1121 			err = got_error_path(pe->path, GOT_ERR_NO_TREE_ENTRY);
1122 			goto done;
1123 		}
1124 		if (id1) {
1125 			err = got_object_get_type(&type1, repo, id1);
1126 			if (err)
1127 				goto done;
1128 		}
1129 		if (id2) {
1130 			err = got_object_get_type(&type2, repo, id2);
1131 			if (err)
1132 				goto done;
1133 		}
1134 		if (type1 == GOT_OBJ_TYPE_ANY &&
1135 		    type2 == GOT_OBJ_TYPE_ANY) {
1136 			err = got_error_path(pe->path, GOT_ERR_NO_OBJ);
1137 			goto done;
1138 		} else if (type1 != GOT_OBJ_TYPE_ANY &&
1139 		    type2 != GOT_OBJ_TYPE_ANY && type1 != type2) {
1140 			err = got_error(GOT_ERR_OBJ_TYPE);
1141 			goto done;
1142 		}
1143 
1144 		if (type1 == GOT_OBJ_TYPE_BLOB ||
1145 		    type2 == GOT_OBJ_TYPE_BLOB) {
1146 			if (id1) {
1147 				err = got_object_open_as_blob(&blob1, repo,
1148 				    id1, 8192, fd1);
1149 				if (err)
1150 					goto done;
1151 			}
1152 			if (id2) {
1153 				err = got_object_open_as_blob(&blob2, repo,
1154 				    id2, 8192, fd2);
1155 				if (err)
1156 					goto done;
1157 			}
1158 			err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2,
1159 			    id1 ? pe->path : "/dev/null",
1160 			    id2 ? pe->path : "/dev/null",
1161 			    mode1, mode2, repo);
1162 			if (err)
1163 				goto done;
1164 		} else if (type1 == GOT_OBJ_TYPE_TREE ||
1165 		    type2 == GOT_OBJ_TYPE_TREE) {
1166 			if (id1) {
1167 				err = got_object_open_as_tree(&subtree1, repo,
1168 				    id1);
1169 				if (err)
1170 					goto done;
1171 			}
1172 			if (id2) {
1173 				err = got_object_open_as_tree(&subtree2, repo,
1174 				    id2);
1175 				if (err)
1176 					goto done;
1177 			}
1178 			err = got_diff_tree(subtree1, subtree2, f1, f2,
1179 			    fd1, fd2,
1180 			    id1 ? pe->path : "/dev/null",
1181 			    id2 ? pe->path : "/dev/null",
1182 			    repo, cb, cb_arg, 1);
1183 			if (err)
1184 				goto done;
1185 		} else {
1186 			err = got_error(GOT_ERR_OBJ_TYPE);
1187 			goto done;
1188 		}
1189 	}
1190 done:
1191 	free(id1);
1192 	free(id2);
1193 	if (subtree1)
1194 		got_object_tree_close(subtree1);
1195 	if (subtree2)
1196 		got_object_tree_close(subtree2);
1197 	if (blob1)
1198 		got_object_blob_close(blob1);
1199 	if (blob2)
1200 		got_object_blob_close(blob2);
1201 	return err;
1202 }
1203 
1204 static const struct got_error *
1205 show_object_id(struct got_diff_line **lines, size_t *nlines,
1206     const char *obj_typestr, int ch, const char *id_str, FILE *outfile)
1207 {
1208 	const struct got_error *err;
1209 	int n;
1210 	off_t outoff = 0;
1211 
1212 	n = fprintf(outfile, "%s %c %s\n", obj_typestr, ch, id_str);
1213 	if (n < 0)
1214 		return got_error_from_errno("fprintf");
1215 
1216 	if (lines != NULL && *lines != NULL) {
1217 		if (*nlines == 0) {
1218 			err = add_line_metadata(lines, nlines, 0,
1219 			    GOT_DIFF_LINE_META);
1220 			if (err)
1221 				return err;
1222 		} else
1223 			outoff = (*lines)[*nlines - 1].offset;
1224 
1225 		outoff += n;
1226 		err = add_line_metadata(lines, nlines, outoff,
1227 		    GOT_DIFF_LINE_META);
1228 		if (err)
1229 			return err;
1230 	}
1231 
1232 	return NULL;
1233 }
1234 
1235 static const struct got_error *
1236 diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1237     FILE *f1, FILE *f2, int fd1, int fd2,
1238     struct got_object_id *id1, struct got_object_id *id2,
1239     struct got_pathlist_head *paths, const char *label1, const char *label2,
1240     int diff_context, int ignore_whitespace, int force_text_diff,
1241     struct got_diffstat_cb_arg *dsa, struct got_repository *repo,
1242     FILE *outfile, enum got_diff_algorithm diff_algo)
1243 {
1244 	const struct got_error *err;
1245 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1246 	struct got_diff_blob_output_unidiff_arg arg;
1247 	int want_linemeta = (lines != NULL && *lines != NULL);
1248 
1249 	if (id1 == NULL && id2 == NULL)
1250 		return got_error(GOT_ERR_NO_OBJ);
1251 
1252 	if (id1) {
1253 		err = got_object_open_as_tree(&tree1, repo, id1);
1254 		if (err)
1255 			goto done;
1256 	}
1257 	if (id2) {
1258 		err = got_object_open_as_tree(&tree2, repo, id2);
1259 		if (err)
1260 			goto done;
1261 	}
1262 
1263 	arg.diff_algo = diff_algo;
1264 	arg.diff_context = diff_context;
1265 	arg.ignore_whitespace = ignore_whitespace;
1266 	arg.force_text_diff = force_text_diff;
1267 	arg.diffstat = dsa;
1268 	arg.outfile = outfile;
1269 	if (want_linemeta) {
1270 		arg.lines = *lines;
1271 		arg.nlines = *nlines;
1272 	} else {
1273 		arg.lines = NULL;
1274 		arg.nlines = 0;
1275 	}
1276 	if (paths == NULL || TAILQ_EMPTY(paths))
1277 		err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2, label1,
1278 		    label2, repo, got_diff_blob_output_unidiff, &arg, 1);
1279 	else
1280 		err = diff_paths(tree1, tree2, f1, f2, fd1, fd2, paths, repo,
1281 		    got_diff_blob_output_unidiff, &arg);
1282 	if (want_linemeta) {
1283 		*lines = arg.lines; /* was likely re-allocated */
1284 		*nlines = arg.nlines;
1285 	}
1286 done:
1287 	if (tree1)
1288 		got_object_tree_close(tree1);
1289 	if (tree2)
1290 		got_object_tree_close(tree2);
1291 	return err;
1292 }
1293 
1294 const struct got_error *
1295 got_diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1296     FILE *f1, FILE *f2, int fd1, int fd2,
1297     struct got_object_id *id1, struct got_object_id *id2,
1298     struct got_pathlist_head *paths, const char *label1, const char *label2,
1299     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
1300     int force_text_diff, struct got_diffstat_cb_arg *dsa,
1301     struct got_repository *repo, FILE *outfile)
1302 {
1303 	const struct got_error *err;
1304 	char *idstr = NULL;
1305 
1306 	if (id1 == NULL && id2 == NULL)
1307 		return got_error(GOT_ERR_NO_OBJ);
1308 
1309 	if (id1) {
1310 		err = got_object_id_str(&idstr, id1);
1311 		if (err)
1312 			goto done;
1313 		err = show_object_id(lines, nlines, "tree", '-', idstr, outfile);
1314 		if (err)
1315 			goto done;
1316 		free(idstr);
1317 		idstr = NULL;
1318 	} else {
1319 		err = show_object_id(lines, nlines, "tree", '-', "/dev/null",
1320 		    outfile);
1321 		if (err)
1322 			goto done;
1323 	}
1324 
1325 	if (id2) {
1326 		err = got_object_id_str(&idstr, id2);
1327 		if (err)
1328 			goto done;
1329 		err = show_object_id(lines, nlines, "tree", '+', idstr, outfile);
1330 		if (err)
1331 			goto done;
1332 		free(idstr);
1333 		idstr = NULL;
1334 	} else {
1335 		err = show_object_id(lines, nlines, "tree", '+', "/dev/null",
1336 		    outfile);
1337 		if (err)
1338 			goto done;
1339 	}
1340 
1341 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2, id1, id2,
1342 	    paths, label1, label2, diff_context, ignore_whitespace,
1343 	    force_text_diff, dsa, repo, outfile, diff_algo);
1344 done:
1345 	free(idstr);
1346 	return err;
1347 }
1348 
1349 const struct got_error *
1350 got_diff_objects_as_commits(struct got_diff_line **lines, size_t *nlines,
1351     FILE *f1, FILE *f2, int fd1, int fd2,
1352     struct got_object_id *id1, struct got_object_id *id2,
1353     struct got_pathlist_head *paths, enum got_diff_algorithm diff_algo,
1354     int diff_context, int ignore_whitespace, int force_text_diff,
1355     struct got_diffstat_cb_arg *dsa, struct got_repository *repo, FILE *outfile)
1356 {
1357 	const struct got_error *err;
1358 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
1359 	char *idstr = NULL;
1360 
1361 	if (id2 == NULL)
1362 		return got_error(GOT_ERR_NO_OBJ);
1363 
1364 	if (id1) {
1365 		err = got_object_open_as_commit(&commit1, repo, id1);
1366 		if (err)
1367 			goto done;
1368 		err = got_object_id_str(&idstr, id1);
1369 		if (err)
1370 			goto done;
1371 		err = show_object_id(lines, nlines, "commit", '-', idstr,
1372 		    outfile);
1373 		if (err)
1374 			goto done;
1375 		free(idstr);
1376 		idstr = NULL;
1377 	} else {
1378 		err = show_object_id(lines, nlines, "commit", '-', "/dev/null",
1379 		    outfile);
1380 		if (err)
1381 			goto done;
1382 	}
1383 
1384 	err = got_object_open_as_commit(&commit2, repo, id2);
1385 	if (err)
1386 		goto done;
1387 
1388 	err = got_object_id_str(&idstr, id2);
1389 	if (err)
1390 		goto done;
1391 	err = show_object_id(lines, nlines, "commit", '+', idstr, outfile);
1392 	if (err)
1393 		goto done;
1394 
1395 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2,
1396 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
1397 	    got_object_commit_get_tree_id(commit2), paths, "", "",
1398 	    diff_context, ignore_whitespace, force_text_diff, dsa, repo,
1399 	    outfile, diff_algo);
1400 done:
1401 	if (commit1)
1402 		got_object_commit_close(commit1);
1403 	if (commit2)
1404 		got_object_commit_close(commit2);
1405 	free(idstr);
1406 	return err;
1407 }
1408 
1409 const struct got_error *
1410 got_diff_files(struct got_diffreg_result **resultp,
1411     FILE *f1, int f1_exists, const char *label1, FILE *f2, int f2_exists,
1412     const char *label2, int diff_context, int ignore_whitespace,
1413     int force_text_diff, FILE *outfile, enum got_diff_algorithm diff_algo)
1414 {
1415 	const struct got_error *err = NULL;
1416 	struct got_diffreg_result *diffreg_result = NULL;
1417 
1418 	if (resultp)
1419 		*resultp = NULL;
1420 
1421 	if (outfile) {
1422 		fprintf(outfile, "file - %s\n",
1423 		    f1_exists ? label1 : "/dev/null");
1424 		fprintf(outfile, "file + %s\n",
1425 		    f2_exists ? label2 : "/dev/null");
1426 	}
1427 
1428 	err = got_diffreg(&diffreg_result, f1, f2, diff_algo,
1429 	    ignore_whitespace, force_text_diff);
1430 	if (err)
1431 		goto done;
1432 
1433 	if (outfile) {
1434 		err = got_diffreg_output(NULL, NULL, diffreg_result,
1435 		    f1_exists, f2_exists, label1, label2,
1436 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
1437 		if (err)
1438 			goto done;
1439 	}
1440 
1441 done:
1442 	if (resultp && err == NULL)
1443 		*resultp = diffreg_result;
1444 	else if (diffreg_result) {
1445 		const struct got_error *free_err;
1446 
1447 		free_err = got_diffreg_result_free(diffreg_result);
1448 		if (free_err && err == NULL)
1449 			err = free_err;
1450 	}
1451 
1452 	return err;
1453 }