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Date:: Sat Jun 1 14:22:43 2019 UTC
Message:: generalize got_diff_tree() by adding a diff output callback
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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_repository.h"
28 #include "got_object.h"
29 #include "got_error.h"
30 #include "got_diff.h"
31 #include "got_opentemp.h"
32 #include "got_path.h"
33 
34 #include "got_lib_diff.h"
35 #include "got_lib_delta.h"
36 #include "got_lib_inflate.h"
37 #include "got_lib_object.h"
38 
39 static const struct got_error *
40 diff_blobs(struct got_blob_object *blob1, struct got_blob_object *blob2,
41     const char *label1, const char *label2, int diff_context, FILE *outfile,
42     struct got_diff_changes *changes)
43 {
44 	struct got_diff_state ds;
45 	struct got_diff_args args;
46 	const struct got_error *err = NULL;
47 	FILE *f1 = NULL, *f2 = NULL;
48 	char hex1[SHA1_DIGEST_STRING_LENGTH];
49 	char hex2[SHA1_DIGEST_STRING_LENGTH];
50 	char *idstr1 = NULL, *idstr2 = NULL;
51 	size_t size1, size2;
52 	int res, flags = 0;
53 
54 	if (blob1) {
55 		f1 = got_opentemp();
56 		if (f1 == NULL)
57 			return got_error_from_errno("got_opentemp");
58 	} else
59 		flags |= D_EMPTY1;
60 
61 	if (blob2) {
62 		f2 = got_opentemp();
63 		if (f2 == NULL) {
64 			err = got_error_from_errno("got_opentemp");
65 			fclose(f1);
66 			return err;
67 		}
68 	} else
69 		flags |= D_EMPTY2;
70 
71 	size1 = 0;
72 	if (blob1) {
73 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
74 		err = got_object_blob_dump_to_file(&size1, NULL, f1, blob1);
75 		if (err)
76 			goto done;
77 	} else
78 		idstr1 = "/dev/null";
79 
80 	size2 = 0;
81 	if (blob2) {
82 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
83 		err = got_object_blob_dump_to_file(&size2, NULL, f2, blob2);
84 		if (err)
85 			goto done;
86 	} else
87 		idstr2 = "/dev/null";
88 
89 	memset(&ds, 0, sizeof(ds));
90 	/* XXX should stat buffers be passed in args instead of ds? */
91 	ds.stb1.st_mode = S_IFREG;
92 	if (blob1)
93 		ds.stb1.st_size = size1;
94 	ds.stb1.st_mtime = 0; /* XXX */
95 
96 	ds.stb2.st_mode = S_IFREG;
97 	if (blob2)
98 		ds.stb2.st_size = size2;
99 	ds.stb2.st_mtime = 0; /* XXX */
100 
101 	memset(&args, 0, sizeof(args));
102 	args.diff_format = D_UNIFIED;
103 	args.label[0] = label1 ? label1 : idstr1;
104 	args.label[1] = label2 ? label2 : idstr2;
105 	args.diff_context = diff_context;
106 	flags |= D_PROTOTYPE;
107 
108 	if (outfile) {
109 		fprintf(outfile, "blob - %s\n", idstr1);
110 		fprintf(outfile, "blob + %s\n", idstr2);
111 	}
112 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile, changes);
113 done:
114 	if (f1 && fclose(f1) != 0 && err == NULL)
115 		err = got_error_from_errno("fclose");
116 	if (f2 && fclose(f2) != 0 && err == NULL)
117 		err = got_error_from_errno("fclose");
118 	return err;
119 }
120 
121 const struct got_error *
122 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
123     struct got_blob_object *blob2, struct got_object_id *id1,
124     struct got_object_id *id2, const char *label1, const char *label2,
125     struct got_repository *repo)
126 {
127 	struct got_diff_blob_output_unidiff_arg *a = arg;
128 
129 	return diff_blobs(blob1, blob2, label1, label2, a->diff_context,
130 	    a->outfile, NULL);
131 }
132 
133 const struct got_error *
134 got_diff_blob(struct got_blob_object *blob1, struct got_blob_object *blob2,
135     const char *label1, const char *label2, int diff_context, FILE *outfile)
136 {
137 	return diff_blobs(blob1, blob2, label1, label2, diff_context, outfile,
138 	    NULL);
139 }
140 
141 const struct got_error *
142 got_diff_blob_file(struct got_blob_object *blob1, FILE *f2, size_t size2,
143     const char *label2, int diff_context, FILE *outfile)
144 {
145 	struct got_diff_state ds;
146 	struct got_diff_args args;
147 	const struct got_error *err = NULL;
148 	FILE *f1 = NULL;
149 	char hex1[SHA1_DIGEST_STRING_LENGTH];
150 	char *idstr1 = NULL;
151 	size_t size1;
152 	int res, flags = 0;
153 
154 	size1 = 0;
155 	if (blob1) {
156 		f1 = got_opentemp();
157 		if (f1 == NULL)
158 			return got_error_from_errno("got_opentemp");
159 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
160 		err = got_object_blob_dump_to_file(&size1, NULL, f1, blob1);
161 		if (err)
162 			goto done;
163 	} else {
164 		flags |= D_EMPTY1;
165 		idstr1 = "/dev/null";
166 	}
167 
168 	if (f2 == NULL)
169 		flags |= D_EMPTY2;
170 
171 	memset(&ds, 0, sizeof(ds));
172 	/* XXX should stat buffers be passed in args instead of ds? */
173 	ds.stb1.st_mode = S_IFREG;
174 	if (blob1)
175 		ds.stb1.st_size = size1;
176 	ds.stb1.st_mtime = 0; /* XXX */
177 
178 	ds.stb2.st_mode = S_IFREG;
179 	ds.stb2.st_size = size2;
180 	ds.stb2.st_mtime = 0; /* XXX */
181 
182 	memset(&args, 0, sizeof(args));
183 	args.diff_format = D_UNIFIED;
184 	args.label[0] = label2;
185 	args.label[1] = label2;
186 	args.diff_context = diff_context;
187 	flags |= D_PROTOTYPE;
188 
189 	fprintf(outfile, "blob - %s\n", idstr1);
190 	fprintf(outfile, "file + %s\n", f2 == NULL ? "/dev/null" : label2);
191 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile, NULL);
192 done:
193 	if (f1 && fclose(f1) != 0 && err == NULL)
194 		err = got_error_from_errno("fclose");
195 	return err;
196 }
197 
198 const struct got_error *
199 got_diff_blob_lines_changed(struct got_diff_changes **changes,
200     struct got_blob_object *blob1, struct got_blob_object *blob2)
201 {
202 	const struct got_error *err = NULL;
203 
204 	*changes = calloc(1, sizeof(**changes));
205 	if (*changes == NULL)
206 		return got_error_from_errno("calloc");
207 	SIMPLEQ_INIT(&(*changes)->entries);
208 
209 	err = diff_blobs(blob1, blob2, NULL, NULL, 3, NULL, *changes);
210 	if (err) {
211 		got_diff_free_changes(*changes);
212 		*changes = NULL;
213 	}
214 	return err;
215 }
216 
217 void
218 got_diff_free_changes(struct got_diff_changes *changes)
219 {
220 	struct got_diff_change *change;
221 	while (!SIMPLEQ_EMPTY(&changes->entries)) {
222 		change = SIMPLEQ_FIRST(&changes->entries);
223 		SIMPLEQ_REMOVE_HEAD(&changes->entries, entry);
224 		free(change);
225 	}
226 	free(changes);
227 }
228 
229 static const struct got_error *
230 diff_added_blob(struct got_object_id *id, const char *label,
231     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
232 {
233 	const struct got_error *err;
234 	struct got_blob_object  *blob = NULL;
235 	struct got_object *obj = NULL;
236 
237 	err = got_object_open(&obj, repo, id);
238 	if (err)
239 		return err;
240 
241 	err = got_object_blob_open(&blob, repo, obj, 8192);
242 	if (err)
243 		goto done;
244 	err = cb(cb_arg, NULL, blob, NULL, id, NULL, label, repo);
245 done:
246 	got_object_close(obj);
247 	if (blob)
248 		got_object_blob_close(blob);
249 	return err;
250 }
251 
252 static const struct got_error *
253 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
254     const char *label1, const char *label2, struct got_repository *repo,
255     got_diff_blob_cb cb, void *cb_arg)
256 {
257 	const struct got_error *err;
258 	struct got_object *obj1 = NULL;
259 	struct got_object *obj2 = NULL;
260 	struct got_blob_object *blob1 = NULL;
261 	struct got_blob_object *blob2 = NULL;
262 
263 	err = got_object_open(&obj1, repo, id1);
264 	if (err)
265 		return err;
266 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
267 		err = got_error(GOT_ERR_OBJ_TYPE);
268 		goto done;
269 	}
270 
271 	err = got_object_open(&obj2, repo, id2);
272 	if (err)
273 		goto done;
274 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
275 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
276 		goto done;
277 	}
278 
279 	err = got_object_blob_open(&blob1, repo, obj1, 8192);
280 	if (err)
281 		goto done;
282 
283 	err = got_object_blob_open(&blob2, repo, obj2, 8192);
284 	if (err)
285 		goto done;
286 
287 	err = cb(cb_arg, blob1, blob2, id1, id2, label1, label2, repo);
288 done:
289 	if (obj1)
290 		got_object_close(obj1);
291 	if (obj2)
292 		got_object_close(obj2);
293 	if (blob1)
294 		got_object_blob_close(blob1);
295 	if (blob2)
296 		got_object_blob_close(blob2);
297 	return err;
298 }
299 
300 static const struct got_error *
301 diff_deleted_blob(struct got_object_id *id, const char *label,
302     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
303 {
304 	const struct got_error *err;
305 	struct got_blob_object  *blob = NULL;
306 	struct got_object *obj = NULL;
307 
308 	err = got_object_open(&obj, repo, id);
309 	if (err)
310 		return err;
311 
312 	err = got_object_blob_open(&blob, repo, obj, 8192);
313 	if (err)
314 		goto done;
315 	err = cb(cb_arg, blob, NULL, id, NULL, label, NULL, repo);
316 done:
317 	got_object_close(obj);
318 	if (blob)
319 		got_object_blob_close(blob);
320 	return err;
321 }
322 
323 static const struct got_error *
324 diff_added_tree(struct got_object_id *id, const char *label,
325     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
326 {
327 	const struct got_error *err = NULL;
328 	struct got_object *treeobj = NULL;
329 	struct got_tree_object *tree = NULL;
330 
331 	err = got_object_open(&treeobj, repo, id);
332 	if (err)
333 		goto done;
334 
335 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
336 		err = got_error(GOT_ERR_OBJ_TYPE);
337 		goto done;
338 	}
339 
340 	err = got_object_tree_open(&tree, repo, treeobj);
341 	if (err)
342 		goto done;
343 
344 	err = got_diff_tree(NULL, tree, NULL, label, repo, cb, cb_arg);
345 done:
346 	if (tree)
347 		got_object_tree_close(tree);
348 	if (treeobj)
349 		got_object_close(treeobj);
350 	return err;
351 }
352 
353 static const struct got_error *
354 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
355     const char *label1, const char *label2, struct got_repository *repo,
356     got_diff_blob_cb cb, void *cb_arg)
357 {
358 	const struct got_error *err;
359 	struct got_object *treeobj1 = NULL;
360 	struct got_object *treeobj2 = NULL;
361 	struct got_tree_object *tree1 = NULL;
362 	struct got_tree_object *tree2 = NULL;
363 
364 	err = got_object_open(&treeobj1, repo, id1);
365 	if (err)
366 		goto done;
367 
368 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
369 		err = got_error(GOT_ERR_OBJ_TYPE);
370 		goto done;
371 	}
372 
373 	err = got_object_open(&treeobj2, repo, id2);
374 	if (err)
375 		goto done;
376 
377 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
378 		err = got_error(GOT_ERR_OBJ_TYPE);
379 		goto done;
380 	}
381 
382 	err = got_object_tree_open(&tree1, repo, treeobj1);
383 	if (err)
384 		goto done;
385 
386 	err = got_object_tree_open(&tree2, repo, treeobj2);
387 	if (err)
388 		goto done;
389 
390 	err = got_diff_tree(tree1, tree2, label1, label2, repo, cb, cb_arg);
391 
392 done:
393 	if (tree1)
394 		got_object_tree_close(tree1);
395 	if (tree2)
396 		got_object_tree_close(tree2);
397 	if (treeobj1)
398 		got_object_close(treeobj1);
399 	if (treeobj2)
400 		got_object_close(treeobj2);
401 	return err;
402 }
403 
404 static const struct got_error *
405 diff_deleted_tree(struct got_object_id *id, const char *label,
406     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
407 {
408 	const struct got_error *err;
409 	struct got_object *treeobj = NULL;
410 	struct got_tree_object *tree = NULL;
411 
412 	err = got_object_open(&treeobj, repo, id);
413 	if (err)
414 		goto done;
415 
416 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
417 		err = got_error(GOT_ERR_OBJ_TYPE);
418 		goto done;
419 	}
420 
421 	err = got_object_tree_open(&tree, repo, treeobj);
422 	if (err)
423 		goto done;
424 
425 	err = got_diff_tree(tree, NULL, label, NULL, repo, cb, cb_arg);
426 done:
427 	if (tree)
428 		got_object_tree_close(tree);
429 	if (treeobj)
430 		got_object_close(treeobj);
431 	return err;
432 }
433 
434 static const struct got_error *
435 diff_kind_mismatch(struct got_object_id *id1, struct got_object_id *id2,
436     const char *label1, const char *label2, struct got_repository *repo,
437     got_diff_blob_cb cb, void *cb_arg)
438 {
439 	/* XXX TODO */
440 	return NULL;
441 }
442 
443 static const struct got_error *
444 diff_entry_old_new(const struct got_tree_entry *te1,
445     const struct got_tree_entry *te2, const char *label1, const char *label2,
446     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
447 {
448 	const struct got_error *err = NULL;
449 	int id_match;
450 
451 	if (te2 == NULL) {
452 		if (S_ISDIR(te1->mode))
453 			err = diff_deleted_tree(te1->id, label1, repo,
454 			    cb, cb_arg);
455 		else
456 			err = diff_deleted_blob(te1->id, label1, repo,
457 			    cb, cb_arg);
458 		return err;
459 	}
460 
461 	id_match = (got_object_id_cmp(te1->id, te2->id) == 0);
462 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
463 		if (!id_match)
464 			return diff_modified_tree(te1->id, te2->id,
465 			    label1, label2, repo, cb, cb_arg);
466 	} else if (S_ISREG(te1->mode) && S_ISREG(te2->mode)) {
467 		if (!id_match)
468 			return diff_modified_blob(te1->id, te2->id,
469 			    label1, label2, repo, cb, cb_arg);
470 	}
471 
472 	if (id_match)
473 		return NULL;
474 
475 	return diff_kind_mismatch(te1->id, te2->id, label1, label2, repo,
476 	    cb, cb_arg);
477 }
478 
479 static const struct got_error *
480 diff_entry_new_old(const struct got_tree_entry *te2,
481     const struct got_tree_entry *te1, const char *label2,
482     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
483 {
484 	if (te1 != NULL) /* handled by diff_entry_old_new() */
485 		return NULL;
486 
487 	if (S_ISDIR(te2->mode))
488 		return diff_added_tree(te2->id, label2, repo, cb, cb_arg);
489 
490 	return diff_added_blob(te2->id, label2, repo, cb, cb_arg);
491 }
492 
493 const struct got_error *
494 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
495     const char *label1, const char *label2, struct got_repository *repo,
496     got_diff_blob_cb cb, void *cb_arg)
497 {
498 	const struct got_error *err = NULL;
499 	struct got_tree_entry *te1 = NULL;
500 	struct got_tree_entry *te2 = NULL;
501 	char *l1 = NULL, *l2 = NULL;
502 
503 	if (tree1) {
504 		const struct got_tree_entries *entries;
505 		entries = got_object_tree_get_entries(tree1);
506 		te1 = SIMPLEQ_FIRST(&entries->head);
507 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
508 		    te1->name) == -1)
509 			return got_error_from_errno("asprintf");
510 	}
511 	if (tree2) {
512 		const struct got_tree_entries *entries;
513 		entries = got_object_tree_get_entries(tree2);
514 		te2 = SIMPLEQ_FIRST(&entries->head);
515 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
516 		    te2->name) == -1)
517 			return got_error_from_errno("asprintf");
518 	}
519 
520 	do {
521 		if (te1) {
522 			const struct got_tree_entry *te = NULL;
523 			if (tree2)
524 				te = got_object_tree_find_entry(tree2,
525 				    te1->name);
526 			if (te) {
527 				free(l2);
528 				l2 = NULL;
529 				if (te && asprintf(&l2, "%s%s%s", label2,
530 				    label2[0] ? "/" : "", te->name) == -1)
531 					return
532 					    got_error_from_errno("asprintf");
533 			}
534 			err = diff_entry_old_new(te1, te, l1, l2, repo, cb,
535 			    cb_arg);
536 			if (err)
537 				break;
538 		}
539 
540 		if (te2) {
541 			const struct got_tree_entry *te = NULL;
542 			if (tree1)
543 				te = got_object_tree_find_entry(tree1,
544 				    te2->name);
545 			free(l2);
546 			if (te) {
547 				if (asprintf(&l2, "%s%s%s", label2,
548 				    label2[0] ? "/" : "", te->name) == -1)
549 					return
550 					    got_error_from_errno("asprintf");
551 			} else {
552 				if (asprintf(&l2, "%s%s%s", label2,
553 				    label2[0] ? "/" : "", te2->name) == -1)
554 					return
555 					    got_error_from_errno("asprintf");
556 			}
557 			err = diff_entry_new_old(te2, te, l2, repo, cb, cb_arg);
558 			if (err)
559 				break;
560 		}
561 
562 		free(l1);
563 		l1 = NULL;
564 		if (te1) {
565 			te1 = SIMPLEQ_NEXT(te1, entry);
566 			if (te1 &&
567 			    asprintf(&l1, "%s%s%s", label1,
568 			    label1[0] ? "/" : "", te1->name) == -1)
569 				return got_error_from_errno("asprintf");
570 		}
571 		free(l2);
572 		l2 = NULL;
573 		if (te2) {
574 			te2 = SIMPLEQ_NEXT(te2, entry);
575 			if (te2 &&
576 			    asprintf(&l2, "%s%s%s", label2,
577 			        label2[0] ? "/" : "", te2->name) == -1)
578 				return got_error_from_errno("asprintf");
579 		}
580 	} while (te1 || te2);
581 
582 	return err;
583 }
584 
585 const struct got_error *
586 got_diff_objects_as_blobs(struct got_object_id *id1, struct got_object_id *id2,
587     const char *label1, const char *label2, int diff_context,
588     struct got_repository *repo, FILE *outfile)
589 {
590 	const struct got_error *err;
591 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
592 
593 	if (id1 == NULL && id2 == NULL)
594 		return got_error(GOT_ERR_NO_OBJ);
595 
596 	if (id1) {
597 		err = got_object_open_as_blob(&blob1, repo, id1, 8192);
598 		if (err)
599 			goto done;
600 	}
601 	if (id2) {
602 		err = got_object_open_as_blob(&blob2, repo, id2, 8192);
603 		if (err)
604 			goto done;
605 	}
606 	err = got_diff_blob(blob1, blob2, label1, label2, diff_context,
607 	    outfile);
608 done:
609 	if (blob1)
610 		got_object_blob_close(blob1);
611 	if (blob2)
612 		got_object_blob_close(blob2);
613 	return err;
614 }
615 
616 const struct got_error *
617 got_diff_objects_as_trees(struct got_object_id *id1, struct got_object_id *id2,
618     char *label1, char *label2, int diff_context, struct got_repository *repo,
619     FILE *outfile)
620 {
621 	const struct got_error *err;
622 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
623 	struct got_diff_blob_output_unidiff_arg arg;
624 
625 	if (id1 == NULL && id2 == NULL)
626 		return got_error(GOT_ERR_NO_OBJ);
627 
628 	if (id1) {
629 		err = got_object_open_as_tree(&tree1, repo, id1);
630 		if (err)
631 			goto done;
632 	}
633 	if (id2) {
634 		err = got_object_open_as_tree(&tree2, repo, id2);
635 		if (err)
636 			goto done;
637 	}
638 	arg.diff_context = diff_context;
639 	arg.outfile = outfile;
640 	err = got_diff_tree(tree1, tree2, label1, label2, repo,
641 	    got_diff_blob_output_unidiff, &arg);
642 done:
643 	if (tree1)
644 		got_object_tree_close(tree1);
645 	if (tree2)
646 		got_object_tree_close(tree2);
647 	return err;
648 }
649 
650 const struct got_error *
651 got_diff_objects_as_commits(struct got_object_id *id1,
652     struct got_object_id *id2, int diff_context,
653     struct got_repository *repo, FILE *outfile)
654 {
655 	const struct got_error *err;
656 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
657 
658 	if (id2 == NULL)
659 		return got_error(GOT_ERR_NO_OBJ);
660 
661 	if (id1) {
662 		err = got_object_open_as_commit(&commit1, repo, id1);
663 		if (err)
664 			goto done;
665 	}
666 
667 	err = got_object_open_as_commit(&commit2, repo, id2);
668 	if (err)
669 		goto done;
670 
671 	err = got_diff_objects_as_trees(
672 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
673 	    got_object_commit_get_tree_id(commit2), "", "", diff_context, repo,
674 	    outfile);
675 done:
676 	if (commit1)
677 		got_object_commit_close(commit1);
678 	if (commit2)
679 		got_object_commit_close(commit2);
680 	return err;
681 }