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) {
150 		if (*nlines > 0)
151 			outoff = (*lines)[*nlines - 1].offset;
152 		else {
153 			err = add_line_metadata(lines, nlines,
154 			    0, GOT_DIFF_LINE_NONE);
155 			if (err != NULL)
156 				goto done;
157 		}
158 	}
159 
160 	if (resultp)
161 		*resultp = NULL;
162 
163 	if (f1) {
164 		err = got_opentemp_truncate(f1);
165 		if (err)
166 			goto done;
167 	}
168 	if (f2) {
169 		err = got_opentemp_truncate(f2);
170 		if (err)
171 			goto done;
172 	}
173 
174 	size1 = 0;
175 	if (blob1) {
176 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
177 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
178 		    blob1);
179 		if (err)
180 			goto done;
181 	} else
182 		idstr1 = "/dev/null";
183 
184 	size2 = 0;
185 	if (blob2) {
186 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
187 		err = got_object_blob_dump_to_file(&size2, NULL, NULL, f2,
188 		    blob2);
189 		if (err)
190 			goto done;
191 	} else
192 		idstr2 = "/dev/null";
193 
194 	if (outfile) {
195 		int modebits;
196 
197 		if (mode1 && mode1 != mode2) {
198 			if (S_ISLNK(mode1))
199 				modebits = S_IFLNK;
200 			else
201 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
202 			if (asprintf(&modestr1, " (mode %o)",
203 			    mode1 & modebits) == -1) {
204 				err = got_error_from_errno("asprintf");
205 				goto done;
206 			}
207 		}
208 		if (mode2 && mode1 != mode2) {
209 			if (S_ISLNK(mode2))
210 				modebits = S_IFLNK;
211 			else
212 				modebits = (S_IRWXU | S_IRWXG | S_IRWXO);
213 			if (asprintf(&modestr2, " (mode %o)",
214 			    mode2 & modebits) == -1) {
215 				err = got_error_from_errno("asprintf");
216 				goto done;
217 			}
218 		}
219 		n = fprintf(outfile, "blob - %s%s\n", idstr1,
220 		    modestr1 ? modestr1 : "");
221 		if (n < 0)
222 			goto done;
223 		outoff += n;
224 		if (lines && *lines) {
225 			err = add_line_metadata(lines, nlines, outoff,
226 			    GOT_DIFF_LINE_BLOB_MIN);
227 			if (err)
228 				goto done;
229 		}
230 
231 		n = fprintf(outfile, "blob + %s%s\n", idstr2,
232 		    modestr2 ? modestr2 : "");
233 		if (n < 0)
234 			goto done;
235 		outoff += n;
236 		if (lines && *lines) {
237 			err = add_line_metadata(lines, nlines, outoff,
238 			    GOT_DIFF_LINE_BLOB_PLUS);
239 			if (err)
240 				goto done;
241 		}
242 	}
243 
244 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
245 	     force_text_diff);
246 	if (err)
247 		goto done;
248 
249 	if (diffstat) {
250 		char	*path = NULL;
251 		int	 status = GOT_STATUS_NO_CHANGE;
252 
253 		if (blob1 == NULL)
254 			status = GOT_STATUS_ADD;
255 		else if (blob2 == NULL)
256 			status = GOT_STATUS_DELETE;
257 		else {
258 			if (strcmp(idstr1, idstr2) != 0)
259 				status = GOT_STATUS_MODIFY;
260 			else if (mode1 != mode2)
261 				status = GOT_STATUS_MODE_CHANGE;
262 		}
263 
264 		if (label1 == NULL && label2 == NULL) {
265 			/* diffstat of blobs, show hash instead of path */
266 			if (asprintf(&path, "%.10s -> %.10s",
267 			    idstr1, idstr2) == -1) {
268 				err = got_error_from_errno("asprintf");
269 				goto done;
270 			}
271 		} else {
272 			if (label2 != NULL &&
273 			    (status != GOT_STATUS_DELETE || label1 == NULL))
274 				path = strdup(label2);
275 			else
276 				path = strdup(label1);
277 			if (path == NULL) {
278 				err = got_error_from_errno("strdup");
279 				goto done;
280 			}
281 		}
282 
283 		err = get_diffstat(diffstat, path, result->result,
284 		    force_text_diff, status);
285 		if (err) {
286 			free(path);
287 			goto done;
288 		}
289 	}
290 
291 	if (outfile) {
292 		err = got_diffreg_output(lines, nlines, result,
293 		    blob1 != NULL, blob2 != NULL,
294 		    label1 ? label1 : idstr1,
295 		    label2 ? label2 : idstr2,
296 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
297 		if (err)
298 			goto done;
299 	}
300 
301 done:
302 	free(modestr1);
303 	free(modestr2);
304 	if (resultp && err == NULL)
305 		*resultp = result;
306 	else if (result) {
307 		free_err = got_diffreg_result_free(result);
308 		if (free_err && err == NULL)
309 			err = free_err;
310 	}
311 
312 	return err;
313 }
314 
315 const struct got_error *
316 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
317     struct got_blob_object *blob2, FILE *f1, FILE *f2,
318     struct got_object_id *id1, struct got_object_id *id2,
319     const char *label1, const char *label2, mode_t mode1, mode_t mode2,
320     struct got_repository *repo)
321 {
322 	struct got_diff_blob_output_unidiff_arg *a = arg;
323 
324 	return diff_blobs(&a->lines, &a->nlines, NULL,
325 	    blob1, blob2, f1, f2, label1, label2, mode1, mode2, a->diff_context,
326 	    a->ignore_whitespace, a->force_text_diff, a->diffstat, a->outfile,
327 	    a->diff_algo);
328 }
329 
330 const struct got_error *
331 got_diff_blob(struct got_diff_line **lines, size_t*nlines,
332     struct got_blob_object *blob1, struct got_blob_object *blob2,
333     FILE *f1, FILE *f2, const char *label1, const char *label2,
334     enum got_diff_algorithm diff_algo, int diff_context,
335     int ignore_whitespace, int force_text_diff,
336     struct got_diffstat_cb_arg *ds, FILE *outfile)
337 {
338 	return diff_blobs(lines, nlines, NULL, blob1, blob2, f1, f2,
339 	    label1, label2, 0, 0, diff_context, ignore_whitespace,
340 	    force_text_diff, ds, outfile, diff_algo);
341 }
342 
343 static const struct got_error *
344 diff_blob_file(struct got_diffreg_result **resultp,
345     struct got_blob_object *blob1, FILE *f1, off_t size1, const char *label1,
346     FILE *f2, int f2_exists, struct stat *sb2, const char *label2,
347     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
348     int force_text_diff, struct got_diffstat_cb_arg *diffstat, FILE *outfile)
349 {
350 	const struct got_error *err = NULL, *free_err;
351 	char hex1[GOT_OBJECT_ID_HEX_MAXLEN];
352 	const char *idstr1 = NULL;
353 	struct got_diffreg_result *result = NULL;
354 
355 	if (resultp)
356 		*resultp = NULL;
357 
358 	if (blob1)
359 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
360 	else
361 		idstr1 = "/dev/null";
362 
363 	if (outfile) {
364 		char	*mode = NULL;
365 
366 		/* display file mode for new added files only */
367 		if (f2_exists && blob1 == NULL) {
368 			int mmask = (S_IRWXU | S_IRWXG | S_IRWXO);
369 
370 			if (S_ISLNK(sb2->st_mode))
371 				mmask = S_IFLNK;
372 			if (asprintf(&mode, " (mode %o)",
373 			    sb2->st_mode & mmask) == -1)
374 				return got_error_from_errno("asprintf");
375 		}
376 		fprintf(outfile, "blob - %s\n", label1 ? label1 : idstr1);
377 		fprintf(outfile, "file + %s%s\n",
378 		    f2_exists ? label2 : "/dev/null", mode ? mode : "");
379 		free(mode);
380 	}
381 
382 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
383 	    force_text_diff);
384 	if (err) {
385 		char msg[GOT_ERR_MAX_MSG_SIZE];
386 		if (snprintf(msg, sizeof(msg), "%s vs %s: %s",
387 		             label1 ? label1 : idstr1,
388 		             f2_exists ? label2 : "/dev/null", err->msg) >= 0) {
389 			err = got_error_msg(err->code, msg);
390 		}
391 		goto done;
392 	}
393 
394 	if (outfile) {
395 		err = got_diffreg_output(NULL, NULL, result,
396 		    blob1 != NULL, f2_exists,
397 		    label2, /* show local file's path, not a blob ID */
398 		    label2, GOT_DIFF_OUTPUT_UNIDIFF,
399 		    diff_context, outfile);
400 		if (err)
401 			goto done;
402 	}
403 
404 	if (diffstat) {
405 		char	*path = NULL;
406 		int	 status = GOT_STATUS_NO_CHANGE;
407 
408 		/*
409 		 * Ignore 'm'ode status change: if there's no accompanying
410 		 * content change, there'll be no diffstat, and if there
411 		 * are actual changes, 'M'odified takes precedence.
412 		 */
413 		if (blob1 == NULL)
414 			status = GOT_STATUS_ADD;
415 		else if (!f2_exists)
416 			status = GOT_STATUS_DELETE;
417 		else
418 			status = GOT_STATUS_MODIFY;
419 
420 		if (label2 != NULL &&
421 		    (status != GOT_STATUS_DELETE || label1 == NULL))
422 			path = strdup(label2);
423 		else
424 			path = strdup(label1);
425 		if (path == NULL) {
426 			err = got_error_from_errno("strdup");
427 			goto done;
428 		}
429 
430 		err = get_diffstat(diffstat, path, result->result,
431 		    force_text_diff, status);
432 		if (err) {
433 			free(path);
434 			goto done;
435 		}
436 	}
437 
438 done:
439 	if (resultp && err == NULL)
440 		*resultp = result;
441 	else if (result) {
442 		free_err = got_diffreg_result_free(result);
443 		if (free_err && err == NULL)
444 			err = free_err;
445 	}
446 	return err;
447 }
448 
449 const struct got_error *
450 got_diff_blob_file(struct got_blob_object *blob1, FILE *f1, off_t size1,
451     const char *label1, FILE *f2, int f2_exists, struct stat *sb2,
452     const char *label2, enum got_diff_algorithm diff_algo, int diff_context,
453     int ignore_whitespace, int force_text_diff,
454     struct got_diffstat_cb_arg *ds, FILE *outfile)
455 {
456 	return diff_blob_file(NULL, blob1, f1, size1, label1, f2, f2_exists,
457 	    sb2, label2, diff_algo, diff_context, ignore_whitespace,
458 	    force_text_diff, ds, outfile);
459 }
460 
461 static const struct got_error *
462 diff_added_blob(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
463     const char *label, mode_t mode, struct got_repository *repo,
464     got_diff_blob_cb cb, void *cb_arg)
465 {
466 	const struct got_error *err;
467 	struct got_blob_object  *blob = NULL;
468 	struct got_object *obj = NULL;
469 
470 	err = got_object_open(&obj, repo, id);
471 	if (err)
472 		return err;
473 
474 	err = got_object_blob_open(&blob, repo, obj, 8192, fd2);
475 	if (err)
476 		goto done;
477 	err = cb(cb_arg, NULL, blob, f1, f2, NULL, id,
478 	    NULL, label, 0, mode, repo);
479 done:
480 	got_object_close(obj);
481 	if (blob)
482 		got_object_blob_close(blob);
483 	return err;
484 }
485 
486 static const struct got_error *
487 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
488     FILE *f1, FILE *f2, int fd1, int fd2,
489     const char *label1, const char *label2,
490     mode_t mode1, mode_t mode2, struct got_repository *repo,
491     got_diff_blob_cb cb, void *cb_arg)
492 {
493 	const struct got_error *err;
494 	struct got_object *obj1 = NULL;
495 	struct got_object *obj2 = NULL;
496 	struct got_blob_object *blob1 = NULL;
497 	struct got_blob_object *blob2 = NULL;
498 
499 	err = got_object_open(&obj1, repo, id1);
500 	if (err)
501 		return err;
502 
503 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
504 		err = got_error(GOT_ERR_OBJ_TYPE);
505 		goto done;
506 	}
507 
508 	err = got_object_open(&obj2, repo, id2);
509 	if (err)
510 		goto done;
511 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
512 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
513 		goto done;
514 	}
515 
516 	err = got_object_blob_open(&blob1, repo, obj1, 8192, fd1);
517 	if (err)
518 		goto done;
519 
520 	err = got_object_blob_open(&blob2, repo, obj2, 8192, fd2);
521 	if (err)
522 		goto done;
523 
524 	err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2, label1, label2,
525 	    mode1, mode2, repo);
526 done:
527 	if (obj1)
528 		got_object_close(obj1);
529 	if (obj2)
530 		got_object_close(obj2);
531 	if (blob1)
532 		got_object_blob_close(blob1);
533 	if (blob2)
534 		got_object_blob_close(blob2);
535 	return err;
536 }
537 
538 static const struct got_error *
539 diff_deleted_blob(struct got_object_id *id, FILE *f1, int fd1,
540    FILE *f2, const char *label, mode_t mode, struct got_repository *repo,
541    got_diff_blob_cb cb, void *cb_arg)
542 {
543 	const struct got_error *err;
544 	struct got_blob_object  *blob = NULL;
545 	struct got_object *obj = NULL;
546 
547 	err = got_object_open(&obj, repo, id);
548 	if (err)
549 		return err;
550 
551 	err = got_object_blob_open(&blob, repo, obj, 8192, fd1);
552 	if (err)
553 		goto done;
554 	err = cb(cb_arg, blob, NULL, f1, f2, id, NULL, label, NULL,
555 	    mode, 0, repo);
556 done:
557 	got_object_close(obj);
558 	if (blob)
559 		got_object_blob_close(blob);
560 	return err;
561 }
562 
563 static const struct got_error *
564 diff_added_tree(struct got_object_id *id, FILE *f1, FILE *f2, int fd2,
565     const char *label, struct got_repository *repo, got_diff_blob_cb cb,
566     void *cb_arg, int diff_content)
567 {
568 	const struct got_error *err = NULL;
569 	struct got_object *treeobj = NULL;
570 	struct got_tree_object *tree = NULL;
571 
572 	err = got_object_open(&treeobj, repo, id);
573 	if (err)
574 		goto done;
575 
576 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
577 		err = got_error(GOT_ERR_OBJ_TYPE);
578 		goto done;
579 	}
580 
581 	err = got_object_tree_open(&tree, repo, treeobj);
582 	if (err)
583 		goto done;
584 
585 	err = got_diff_tree(NULL, tree, f1, f2, -1, fd2, NULL, label,
586 	    repo, cb, cb_arg, diff_content);
587 done:
588 	if (tree)
589 		got_object_tree_close(tree);
590 	if (treeobj)
591 		got_object_close(treeobj);
592 	return err;
593 }
594 
595 static const struct got_error *
596 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
597     FILE *f1, FILE *f2, int fd1, int fd2,
598     const char *label1, const char *label2,
599     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
600     int diff_content)
601 {
602 	const struct got_error *err;
603 	struct got_object *treeobj1 = NULL;
604 	struct got_object *treeobj2 = NULL;
605 	struct got_tree_object *tree1 = NULL;
606 	struct got_tree_object *tree2 = NULL;
607 
608 	err = got_object_open(&treeobj1, repo, id1);
609 	if (err)
610 		goto done;
611 
612 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
613 		err = got_error(GOT_ERR_OBJ_TYPE);
614 		goto done;
615 	}
616 
617 	err = got_object_open(&treeobj2, repo, id2);
618 	if (err)
619 		goto done;
620 
621 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
622 		err = got_error(GOT_ERR_OBJ_TYPE);
623 		goto done;
624 	}
625 
626 	err = got_object_tree_open(&tree1, repo, treeobj1);
627 	if (err)
628 		goto done;
629 
630 	err = got_object_tree_open(&tree2, repo, treeobj2);
631 	if (err)
632 		goto done;
633 
634 	err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2,
635 	    label1, label2, repo, cb, cb_arg, diff_content);
636 
637 done:
638 	if (tree1)
639 		got_object_tree_close(tree1);
640 	if (tree2)
641 		got_object_tree_close(tree2);
642 	if (treeobj1)
643 		got_object_close(treeobj1);
644 	if (treeobj2)
645 		got_object_close(treeobj2);
646 	return err;
647 }
648 
649 static const struct got_error *
650 diff_deleted_tree(struct got_object_id *id, FILE *f1, int fd1,
651     FILE *f2, const char *label, struct got_repository *repo,
652     got_diff_blob_cb cb, void *cb_arg, int diff_content)
653 {
654 	const struct got_error *err;
655 	struct got_object *treeobj = NULL;
656 	struct got_tree_object *tree = NULL;
657 
658 	err = got_object_open(&treeobj, repo, id);
659 	if (err)
660 		goto done;
661 
662 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
663 		err = got_error(GOT_ERR_OBJ_TYPE);
664 		goto done;
665 	}
666 
667 	err = got_object_tree_open(&tree, repo, treeobj);
668 	if (err)
669 		goto done;
670 
671 	err = got_diff_tree(tree, NULL, f1, f2, fd1, -1, label, NULL,
672 	    repo, cb, cb_arg, diff_content);
673 done:
674 	if (tree)
675 		got_object_tree_close(tree);
676 	if (treeobj)
677 		got_object_close(treeobj);
678 	return err;
679 }
680 
681 static const struct got_error *
682 diff_kind_mismatch(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, struct got_repository *repo,
685     got_diff_blob_cb cb, void *cb_arg, int diff_content)
686 {
687 	const struct got_error *err = NULL;
688 
689 	/* 
690 	 * Handle files changing into directories and vice-versa.
691 	 * Disregard edge cases with FIFOs, device nodes, etc for now.
692 	 */
693 	if (!S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
694 		if (S_ISREG(te1->mode)) {
695 			if (diff_content) {
696 				err = diff_deleted_blob(&te1->id, f1, fd1,
697 				    f2, label1, te1->mode, repo, cb, cb_arg);
698 			} else {
699 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
700 				    &te1->id, NULL, label1, NULL,
701 				    te1->mode, 0, repo);
702 			}
703 			if (err)
704 				return err;
705 		}
706 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
707 		    repo, cb, cb_arg, diff_content);
708 	} else if (S_ISDIR(te1->mode) && !S_ISDIR(te2->mode)) {
709 		err = diff_deleted_tree(&te1->id, f1, fd1, f2,
710 		    label1, repo, cb, cb_arg, diff_content);
711 		if (err)
712 			return err;
713 		if (S_ISREG(te2->mode)) {
714 			if (diff_content) {
715 				err = diff_added_blob(&te2->id, f1, f2, fd2,
716 				    label2, te2->mode, repo, cb, cb_arg);
717 			} else {
718 				err = cb(cb_arg, NULL, NULL, NULL, NULL, NULL,
719 				    &te2->id, NULL, label2, 0, te2->mode, repo);
720 			}
721 			if (err)
722 				return err;
723 		}
724 	}
725 
726 	return NULL;
727 }
728 
729 static const struct got_error *
730 diff_entry_old_new(struct got_tree_entry *te1, struct got_tree_entry *te2,
731     FILE *f1, FILE *f2, int fd1, int fd2,
732     const char *label1, const char *label2,
733     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
734     int diff_content)
735 {
736 	const struct got_error *err = NULL;
737 	int id_match;
738 
739 	if (got_object_tree_entry_is_submodule(te1))
740 		return NULL;
741 
742 	if (te2 == NULL) {
743 		if (S_ISDIR(te1->mode))
744 			err = diff_deleted_tree(&te1->id, f1, fd1, f2,
745 			    label1, repo, cb, cb_arg, diff_content);
746 		else {
747 			if (diff_content)
748 				err = diff_deleted_blob(&te1->id, f1, fd1,
749 				    f2, label1, te1->mode, repo, cb, cb_arg);
750 			else
751 				err = cb(cb_arg, NULL, NULL, NULL, NULL,
752 				    &te1->id, NULL, label1, NULL,
753 				    te1->mode, 0, repo);
754 		}
755 		return err;
756 	} else if (got_object_tree_entry_is_submodule(te2))
757 		return NULL;
758 
759 	id_match = (got_object_id_cmp(&te1->id, &te2->id) == 0);
760 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
761 		if (!id_match)
762 			return diff_modified_tree(&te1->id, &te2->id, f1, f2,
763 			    fd1, fd2, label1, label2, repo, cb, cb_arg,
764 			    diff_content);
765 	} else if ((S_ISREG(te1->mode) || S_ISLNK(te1->mode)) &&
766 	    (S_ISREG(te2->mode) || S_ISLNK(te2->mode))) {
767 		if (!id_match ||
768 		    ((te1->mode & (S_IFLNK | S_IXUSR))) !=
769 		    (te2->mode & (S_IFLNK | S_IXUSR))) {
770 			if (diff_content)
771 				return diff_modified_blob(&te1->id, &te2->id,
772 				    f1, f2, fd1, fd2, label1, label2,
773 				    te1->mode, te2->mode, repo, cb, cb_arg);
774 			else
775 				return cb(cb_arg, NULL, NULL, NULL, NULL,
776 				    &te1->id, &te2->id, label1, label2,
777 				    te1->mode, te2->mode, repo);
778 		}
779 	}
780 
781 	if (id_match)
782 		return NULL;
783 
784 	return diff_kind_mismatch(te1, te2, f1, f2, fd1, fd2,
785 	    label1, label2, repo, cb, cb_arg, diff_content);
786 }
787 
788 static const struct got_error *
789 diff_entry_new_old(struct got_tree_entry *te2,
790     struct got_tree_entry *te1, FILE *f1, FILE *f2, int fd2, const char *label2,
791     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
792     int diff_content)
793 {
794 	if (te1 != NULL) /* handled by diff_entry_old_new() */
795 		return NULL;
796 
797 	if (got_object_tree_entry_is_submodule(te2))
798 		return NULL;
799 
800 	if (S_ISDIR(te2->mode))
801 		return diff_added_tree(&te2->id, f1, f2, fd2, label2,
802 		    repo, cb, cb_arg, diff_content);
803 
804 	if (diff_content)
805 		return diff_added_blob(&te2->id, f1, f2, fd2,
806 		    label2, te2->mode, repo, cb, cb_arg);
807 
808 	return cb(cb_arg, NULL, NULL, NULL, NULL, NULL, &te2->id,
809 	    NULL, label2, 0, te2->mode, repo);
810 }
811 
812 const struct got_error *
813 got_diff_tree_compute_diffstat(void *arg, struct got_blob_object *blob1,
814     struct got_blob_object *blob2, FILE *f1, FILE *f2,
815     struct got_object_id *id1, struct got_object_id *id2,
816     const char *label1, const char *label2,
817     mode_t mode1, mode_t mode2, struct got_repository *repo)
818 {
819 	const struct got_error		*err = NULL;
820 	struct got_diffreg_result	*result = NULL;
821 	struct got_diffstat_cb_arg	*a = arg;
822 	char				*path = NULL;
823 	int				 status = GOT_STATUS_NO_CHANGE;
824 
825 	path = strdup(label2 ? label2 : label1);
826 	if (path == NULL)
827 		return got_error_from_errno("strdup");
828 
829 	if (id1 == NULL)
830 		status = GOT_STATUS_ADD;
831 	else if (id2 == NULL)
832 		status = GOT_STATUS_DELETE;
833 	else {
834 		if (got_object_id_cmp(id1, id2) != 0)
835 			status = GOT_STATUS_MODIFY;
836 		else if (mode1 != mode2)
837 			status = GOT_STATUS_MODE_CHANGE;
838 	}
839 
840 	if (f1) {
841 		err = got_opentemp_truncate(f1);
842 		if (err)
843 			goto done;
844 	}
845 	if (f2) {
846 		err = got_opentemp_truncate(f2);
847 		if (err)
848 			goto done;
849 	}
850 
851 	if (blob1) {
852 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1,
853 		    blob1);
854 		if (err)
855 			goto done;
856 	}
857 	if (blob2) {
858 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f2,
859 		    blob2);
860 		if (err)
861 			goto done;
862 	}
863 
864 	err = got_diffreg(&result, f1, f2, a->diff_algo, a->ignore_ws,
865 	    a->force_text);
866 	if (err)
867 		goto done;
868 
869 	err = get_diffstat(a, path, result->result, a->force_text, status);
870 
871 done:
872 	if (result) {
873 		const struct got_error *free_err;
874 
875 		free_err = got_diffreg_result_free(result);
876 		if (free_err && err == NULL)
877 			err = free_err;
878 	}
879 	if (err)
880 		free(path);
881 	return err;
882 }
883 
884 const struct got_error *
885 got_diff_tree_collect_changed_paths(void *arg, struct got_blob_object *blob1,
886     struct got_blob_object *blob2, FILE *f1, FILE *f2,
887     struct got_object_id *id1, struct got_object_id *id2,
888     const char *label1, const char *label2,
889     mode_t mode1, mode_t mode2, struct got_repository *repo)
890 {
891 	const struct got_error *err = NULL;
892 	struct got_pathlist_head *paths = arg;
893 	struct got_diff_changed_path *change = NULL;
894 	char *path = NULL;
895 
896 	path = strdup(label2 ? label2 : label1);
897 	if (path == NULL)
898 		return got_error_from_errno("strdup");
899 
900 	change = malloc(sizeof(*change));
901 	if (change == NULL) {
902 		err = got_error_from_errno("malloc");
903 		goto done;
904 	}
905 
906 	change->status = GOT_STATUS_NO_CHANGE;
907 	if (id1 == NULL)
908 		change->status = GOT_STATUS_ADD;
909 	else if (id2 == NULL)
910 		change->status = GOT_STATUS_DELETE;
911 	else {
912 		if (got_object_id_cmp(id1, id2) != 0)
913 			change->status = GOT_STATUS_MODIFY;
914 		else if (mode1 != mode2)
915 			change->status = GOT_STATUS_MODE_CHANGE;
916 	}
917 
918 	err = got_pathlist_append(paths, path, change);
919 done:
920 	if (err) {
921 		free(path);
922 		free(change);
923 	}
924 	return err;
925 }
926 
927 const struct got_error *
928 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
929     FILE *f1, FILE *f2, int fd1, int fd2,
930     const char *label1, const char *label2,
931     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
932     int diff_content)
933 {
934 	const struct got_error *err = NULL;
935 	struct got_tree_entry *te1 = NULL;
936 	struct got_tree_entry *te2 = NULL;
937 	char *l1 = NULL, *l2 = NULL;
938 	int tidx1 = 0, tidx2 = 0;
939 
940 	if (tree1) {
941 		te1 = got_object_tree_get_entry(tree1, 0);
942 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
943 		    te1->name) == -1)
944 			return got_error_from_errno("asprintf");
945 	}
946 	if (tree2) {
947 		te2 = got_object_tree_get_entry(tree2, 0);
948 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
949 		    te2->name) == -1) {
950 			err = got_error_from_errno("asprintf");
951 			goto done;
952 		}
953 	}
954 
955 	do {
956 		if (te1) {
957 			struct got_tree_entry *te = NULL;
958 
959 			if (tree2)
960 				te = got_object_tree_find_entry(tree2,
961 				    te1->name);
962 			if (te) {
963 				free(l2);
964 				l2 = NULL;
965 				if (te && asprintf(&l2, "%s%s%s", label2,
966 				    label2[0] ? "/" : "", te->name) == -1) {
967 					err = got_error_from_errno("asprintf");
968 					goto done;
969 				}
970 			}
971 
972 			err = diff_entry_old_new(te1, te, f1, f2, fd1, fd2,
973 			    l1, l2, repo, cb, cb_arg, diff_content);
974 			if (err)
975 				break;
976 		}
977 
978 		if (te2) {
979 			struct got_tree_entry *te = NULL;
980 
981 			if (tree1)
982 				te = got_object_tree_find_entry(tree1,
983 				    te2->name);
984 
985 			free(l2);
986 			l2 = NULL;
987 			if (te) {
988 				if (asprintf(&l2, "%s%s%s", label2,
989 				    label2[0] ? "/" : "", te->name) == -1) {
990 					err = got_error_from_errno("asprintf");
991 					goto done;
992 				}
993 			} else {
994 				if (asprintf(&l2, "%s%s%s", label2,
995 				    label2[0] ? "/" : "", te2->name) == -1) {
996 					err = got_error_from_errno("asprintf");
997 					goto done;
998 				}
999 			}
1000 
1001 			err = diff_entry_new_old(te2, te, f1, f2, fd2, l2,
1002 			    repo, cb, cb_arg, diff_content);
1003 			if (err)
1004 				break;
1005 		}
1006 
1007 		free(l1);
1008 		l1 = NULL;
1009 		if (te1) {
1010 			tidx1++;
1011 			te1 = got_object_tree_get_entry(tree1, tidx1);
1012 			if (te1 &&
1013 			    asprintf(&l1, "%s%s%s", label1,
1014 			    label1[0] ? "/" : "", te1->name) == -1) {
1015 				err = got_error_from_errno("asprintf");
1016 				goto done;
1017 			}
1018 		}
1019 
1020 		free(l2);
1021 		l2 = NULL;
1022 		if (te2) {
1023 			tidx2++;
1024 			te2 = got_object_tree_get_entry(tree2, tidx2);
1025 			if (te2 &&
1026 			    asprintf(&l2, "%s%s%s", label2,
1027 			    label2[0] ? "/" : "", te2->name) == -1) {
1028 				err = got_error_from_errno("asprintf");
1029 				goto done;
1030 			}
1031 		}
1032 	} while (te1 || te2);
1033 
1034 done:
1035 	free(l1);
1036 	free(l2);
1037 	return err;
1038 }
1039 
1040 const struct got_error *
1041 got_diff_objects_as_blobs(struct got_diff_line **lines, size_t *nlines,
1042     FILE *f1, FILE *f2, int fd1, int fd2,
1043     struct got_object_id *id1, struct got_object_id *id2,
1044     const char *label1, const char *label2,
1045     enum got_diff_algorithm diff_algo, int diff_context,
1046     int ignore_whitespace, int force_text_diff, struct got_diffstat_cb_arg *ds,
1047     struct got_repository *repo, FILE *outfile)
1048 {
1049 	const struct got_error *err;
1050 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1051 
1052 	if (id1 == NULL && id2 == NULL)
1053 		return got_error(GOT_ERR_NO_OBJ);
1054 
1055 	if (id1) {
1056 		err = got_object_open_as_blob(&blob1, repo, id1, 8192, fd1);
1057 		if (err)
1058 			goto done;
1059 	}
1060 	if (id2) {
1061 		err = got_object_open_as_blob(&blob2, repo, id2, 8192, fd2);
1062 		if (err)
1063 			goto done;
1064 	}
1065 	err = got_diff_blob(lines, nlines, blob1, blob2, f1, f2, label1, label2,
1066 	    diff_algo, diff_context, ignore_whitespace, force_text_diff,
1067 	    ds, outfile);
1068 done:
1069 	if (blob1)
1070 		got_object_blob_close(blob1);
1071 	if (blob2)
1072 		got_object_blob_close(blob2);
1073 	return err;
1074 }
1075 
1076 static const struct got_error *
1077 diff_paths(struct got_tree_object *tree1, struct got_tree_object *tree2,
1078     FILE *f1, FILE *f2, int fd1, int fd2, struct got_pathlist_head *paths,
1079     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
1080 {
1081 	const struct got_error *err = NULL;
1082 	struct got_pathlist_entry *pe;
1083 	struct got_object_id *id1 = NULL, *id2 = NULL;
1084 	struct got_tree_object *subtree1 = NULL, *subtree2 = NULL;
1085 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
1086 
1087 	TAILQ_FOREACH(pe, paths, entry) {
1088 		int type1 = GOT_OBJ_TYPE_ANY, type2 = GOT_OBJ_TYPE_ANY;
1089 		mode_t mode1 = 0, mode2 = 0;
1090 
1091 		free(id1);
1092 		id1 = NULL;
1093 		free(id2);
1094 		id2 = NULL;
1095 		if (subtree1) {
1096 			got_object_tree_close(subtree1);
1097 			subtree1 = NULL;
1098 		}
1099 		if (subtree2) {
1100 			got_object_tree_close(subtree2);
1101 			subtree2 = NULL;
1102 		}
1103 		if (blob1) {
1104 			got_object_blob_close(blob1);
1105 			blob1 = NULL;
1106 		}
1107 		if (blob2) {
1108 			got_object_blob_close(blob2);
1109 			blob2 = NULL;
1110 		}
1111 		if (tree1) {
1112 			err = got_object_tree_find_path(&id1, &mode1, repo,
1113 			    tree1, pe->path);
1114 			if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1115 				goto done;
1116 		}
1117 		if (tree2) {
1118 			err = got_object_tree_find_path(&id2, &mode2, repo,
1119 			    tree2, pe->path);
1120 			if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
1121 				goto done;
1122 		}
1123 		if (id1 == NULL && id2 == NULL) {
1124 			err = got_error_path(pe->path, GOT_ERR_NO_TREE_ENTRY);
1125 			goto done;
1126 		}
1127 		if (id1) {
1128 			err = got_object_get_type(&type1, repo, id1);
1129 			if (err)
1130 				goto done;
1131 		}
1132 		if (id2) {
1133 			err = got_object_get_type(&type2, repo, id2);
1134 			if (err)
1135 				goto done;
1136 		}
1137 		if (type1 == GOT_OBJ_TYPE_ANY &&
1138 		    type2 == GOT_OBJ_TYPE_ANY) {
1139 			err = got_error_path(pe->path, GOT_ERR_NO_OBJ);
1140 			goto done;
1141 		} else if (type1 != GOT_OBJ_TYPE_ANY &&
1142 		    type2 != GOT_OBJ_TYPE_ANY && type1 != type2) {
1143 			err = got_error(GOT_ERR_OBJ_TYPE);
1144 			goto done;
1145 		}
1146 
1147 		if (type1 == GOT_OBJ_TYPE_BLOB ||
1148 		    type2 == GOT_OBJ_TYPE_BLOB) {
1149 			if (id1) {
1150 				err = got_object_open_as_blob(&blob1, repo,
1151 				    id1, 8192, fd1);
1152 				if (err)
1153 					goto done;
1154 			}
1155 			if (id2) {
1156 				err = got_object_open_as_blob(&blob2, repo,
1157 				    id2, 8192, fd2);
1158 				if (err)
1159 					goto done;
1160 			}
1161 			err = cb(cb_arg, blob1, blob2, f1, f2, id1, id2,
1162 			    id1 ? pe->path : "/dev/null",
1163 			    id2 ? pe->path : "/dev/null",
1164 			    mode1, mode2, repo);
1165 			if (err)
1166 				goto done;
1167 		} else if (type1 == GOT_OBJ_TYPE_TREE ||
1168 		    type2 == GOT_OBJ_TYPE_TREE) {
1169 			if (id1) {
1170 				err = got_object_open_as_tree(&subtree1, repo,
1171 				    id1);
1172 				if (err)
1173 					goto done;
1174 			}
1175 			if (id2) {
1176 				err = got_object_open_as_tree(&subtree2, repo,
1177 				    id2);
1178 				if (err)
1179 					goto done;
1180 			}
1181 			err = got_diff_tree(subtree1, subtree2, f1, f2,
1182 			    fd1, fd2,
1183 			    id1 ? pe->path : "/dev/null",
1184 			    id2 ? pe->path : "/dev/null",
1185 			    repo, cb, cb_arg, 1);
1186 			if (err)
1187 				goto done;
1188 		} else {
1189 			err = got_error(GOT_ERR_OBJ_TYPE);
1190 			goto done;
1191 		}
1192 	}
1193 done:
1194 	free(id1);
1195 	free(id2);
1196 	if (subtree1)
1197 		got_object_tree_close(subtree1);
1198 	if (subtree2)
1199 		got_object_tree_close(subtree2);
1200 	if (blob1)
1201 		got_object_blob_close(blob1);
1202 	if (blob2)
1203 		got_object_blob_close(blob2);
1204 	return err;
1205 }
1206 
1207 static const struct got_error *
1208 show_object_id(struct got_diff_line **lines, size_t *nlines,
1209     const char *obj_typestr, int ch, const char *id_str, FILE *outfile)
1210 {
1211 	const struct got_error *err;
1212 	int n;
1213 	off_t outoff = 0;
1214 
1215 	n = fprintf(outfile, "%s %c %s\n", obj_typestr, ch, id_str);
1216 	if (n < 0)
1217 		return got_error_from_errno("fprintf");
1218 
1219 	if (lines != NULL && *lines != NULL) {
1220 		if (*nlines == 0) {
1221 			err = add_line_metadata(lines, nlines, 0,
1222 			    GOT_DIFF_LINE_META);
1223 			if (err)
1224 				return err;
1225 		} else
1226 			outoff = (*lines)[*nlines - 1].offset;
1227 
1228 		outoff += n;
1229 		err = add_line_metadata(lines, nlines, outoff,
1230 		    GOT_DIFF_LINE_META);
1231 		if (err)
1232 			return err;
1233 	}
1234 
1235 	return NULL;
1236 }
1237 
1238 static const struct got_error *
1239 diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1240     FILE *f1, FILE *f2, int fd1, int fd2,
1241     struct got_object_id *id1, struct got_object_id *id2,
1242     struct got_pathlist_head *paths, const char *label1, const char *label2,
1243     int diff_context, int ignore_whitespace, int force_text_diff,
1244     struct got_diffstat_cb_arg *dsa, struct got_repository *repo,
1245     FILE *outfile, enum got_diff_algorithm diff_algo)
1246 {
1247 	const struct got_error *err;
1248 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1249 	struct got_diff_blob_output_unidiff_arg arg;
1250 	int want_linemeta = (lines != NULL && *lines != NULL);
1251 
1252 	if (id1 == NULL && id2 == NULL)
1253 		return got_error(GOT_ERR_NO_OBJ);
1254 
1255 	if (id1) {
1256 		err = got_object_open_as_tree(&tree1, repo, id1);
1257 		if (err)
1258 			goto done;
1259 	}
1260 	if (id2) {
1261 		err = got_object_open_as_tree(&tree2, repo, id2);
1262 		if (err)
1263 			goto done;
1264 	}
1265 
1266 	arg.diff_algo = diff_algo;
1267 	arg.diff_context = diff_context;
1268 	arg.ignore_whitespace = ignore_whitespace;
1269 	arg.force_text_diff = force_text_diff;
1270 	arg.diffstat = dsa;
1271 	arg.outfile = outfile;
1272 	if (want_linemeta) {
1273 		arg.lines = *lines;
1274 		arg.nlines = *nlines;
1275 	} else {
1276 		arg.lines = NULL;
1277 		arg.nlines = 0;
1278 	}
1279 	if (paths == NULL || TAILQ_EMPTY(paths))
1280 		err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2, label1,
1281 		    label2, repo, got_diff_blob_output_unidiff, &arg, 1);
1282 	else
1283 		err = diff_paths(tree1, tree2, f1, f2, fd1, fd2, paths, repo,
1284 		    got_diff_blob_output_unidiff, &arg);
1285 	if (want_linemeta) {
1286 		*lines = arg.lines; /* was likely re-allocated */
1287 		*nlines = arg.nlines;
1288 	}
1289 done:
1290 	if (tree1)
1291 		got_object_tree_close(tree1);
1292 	if (tree2)
1293 		got_object_tree_close(tree2);
1294 	return err;
1295 }
1296 
1297 const struct got_error *
1298 got_diff_objects_as_trees(struct got_diff_line **lines, size_t *nlines,
1299     FILE *f1, FILE *f2, int fd1, int fd2,
1300     struct got_object_id *id1, struct got_object_id *id2,
1301     struct got_pathlist_head *paths, const char *label1, const char *label2,
1302     enum got_diff_algorithm diff_algo, int diff_context, int ignore_whitespace,
1303     int force_text_diff, struct got_diffstat_cb_arg *dsa,
1304     struct got_repository *repo, FILE *outfile)
1305 {
1306 	const struct got_error *err;
1307 	char *idstr = NULL;
1308 
1309 	if (id1 == NULL && id2 == NULL)
1310 		return got_error(GOT_ERR_NO_OBJ);
1311 
1312 	if (id1) {
1313 		err = got_object_id_str(&idstr, id1);
1314 		if (err)
1315 			goto done;
1316 		err = show_object_id(lines, nlines, "tree", '-', idstr, outfile);
1317 		if (err)
1318 			goto done;
1319 		free(idstr);
1320 		idstr = NULL;
1321 	} else {
1322 		err = show_object_id(lines, nlines, "tree", '-', "/dev/null",
1323 		    outfile);
1324 		if (err)
1325 			goto done;
1326 	}
1327 
1328 	if (id2) {
1329 		err = got_object_id_str(&idstr, id2);
1330 		if (err)
1331 			goto done;
1332 		err = show_object_id(lines, nlines, "tree", '+', idstr, outfile);
1333 		if (err)
1334 			goto done;
1335 		free(idstr);
1336 		idstr = NULL;
1337 	} else {
1338 		err = show_object_id(lines, nlines, "tree", '+', "/dev/null",
1339 		    outfile);
1340 		if (err)
1341 			goto done;
1342 	}
1343 
1344 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2, id1, id2,
1345 	    paths, label1, label2, diff_context, ignore_whitespace,
1346 	    force_text_diff, dsa, repo, outfile, diff_algo);
1347 done:
1348 	free(idstr);
1349 	return err;
1350 }
1351 
1352 const struct got_error *
1353 got_diff_objects_as_commits(struct got_diff_line **lines, size_t *nlines,
1354     FILE *f1, FILE *f2, int fd1, int fd2,
1355     struct got_object_id *id1, struct got_object_id *id2,
1356     struct got_pathlist_head *paths, enum got_diff_algorithm diff_algo,
1357     int diff_context, int ignore_whitespace, int force_text_diff,
1358     struct got_diffstat_cb_arg *dsa, struct got_repository *repo, FILE *outfile)
1359 {
1360 	const struct got_error *err;
1361 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
1362 	char *idstr = NULL;
1363 
1364 	if (id2 == NULL)
1365 		return got_error(GOT_ERR_NO_OBJ);
1366 
1367 	if (id1) {
1368 		err = got_object_open_as_commit(&commit1, repo, id1);
1369 		if (err)
1370 			goto done;
1371 		err = got_object_id_str(&idstr, id1);
1372 		if (err)
1373 			goto done;
1374 		err = show_object_id(lines, nlines, "commit", '-', idstr,
1375 		    outfile);
1376 		if (err)
1377 			goto done;
1378 		free(idstr);
1379 		idstr = NULL;
1380 	} else {
1381 		err = show_object_id(lines, nlines, "commit", '-', "/dev/null",
1382 		    outfile);
1383 		if (err)
1384 			goto done;
1385 	}
1386 
1387 	err = got_object_open_as_commit(&commit2, repo, id2);
1388 	if (err)
1389 		goto done;
1390 
1391 	err = got_object_id_str(&idstr, id2);
1392 	if (err)
1393 		goto done;
1394 	err = show_object_id(lines, nlines, "commit", '+', idstr, outfile);
1395 	if (err)
1396 		goto done;
1397 
1398 	err = diff_objects_as_trees(lines, nlines, f1, f2, fd1, fd2,
1399 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
1400 	    got_object_commit_get_tree_id(commit2), paths, "", "",
1401 	    diff_context, ignore_whitespace, force_text_diff, dsa, repo,
1402 	    outfile, diff_algo);
1403 done:
1404 	if (commit1)
1405 		got_object_commit_close(commit1);
1406 	if (commit2)
1407 		got_object_commit_close(commit2);
1408 	free(idstr);
1409 	return err;
1410 }
1411 
1412 const struct got_error *
1413 got_diff_files(struct got_diffreg_result **resultp,
1414     FILE *f1, int f1_exists, const char *label1, FILE *f2, int f2_exists,
1415     const char *label2, int diff_context, int ignore_whitespace,
1416     int force_text_diff, FILE *outfile, enum got_diff_algorithm diff_algo)
1417 {
1418 	const struct got_error *err = NULL;
1419 	struct got_diffreg_result *diffreg_result = NULL;
1420 
1421 	if (resultp)
1422 		*resultp = NULL;
1423 
1424 	if (outfile) {
1425 		fprintf(outfile, "file - %s\n",
1426 		    f1_exists ? label1 : "/dev/null");
1427 		fprintf(outfile, "file + %s\n",
1428 		    f2_exists ? label2 : "/dev/null");
1429 	}
1430 
1431 	err = got_diffreg(&diffreg_result, f1, f2, diff_algo,
1432 	    ignore_whitespace, force_text_diff);
1433 	if (err)
1434 		goto done;
1435 
1436 	if (outfile) {
1437 		err = got_diffreg_output(NULL, NULL, diffreg_result,
1438 		    f1_exists, f2_exists, label1, label2,
1439 		    GOT_DIFF_OUTPUT_UNIDIFF, diff_context, outfile);
1440 		if (err)
1441 			goto done;
1442 	}
1443 
1444 done:
1445 	if (resultp && err == NULL)
1446 		*resultp = diffreg_result;
1447 	else if (diffreg_result) {
1448 		const struct got_error *free_err;
1449 
1450 		free_err = got_diffreg_result_free(diffreg_result);
1451 		if (free_err && err == NULL)
1452 			err = free_err;
1453 	}
1454 
1455 	return err;
1456 }