1 /*
2  * Copyright (c) 2017 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/stat.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <limits.h>
24 #include <sha1.h>
25 #include <zlib.h>
26 
27 #include "got_object.h"
28 #include "got_repository.h"
29 #include "got_error.h"
30 #include "got_diff.h"
31 #include "got_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, NULL, f1,
75 		    blob1);
76 		if (err)
77 			goto done;
78 	} else
79 		idstr1 = "/dev/null";
80 
81 	size2 = 0;
82 	if (blob2) {
83 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
84 		err = got_object_blob_dump_to_file(&size2, NULL, NULL, f2,
85 		    blob2);
86 		if (err)
87 			goto done;
88 	} else
89 		idstr2 = "/dev/null";
90 
91 	memset(&ds, 0, sizeof(ds));
92 	/* XXX should stat buffers be passed in args instead of ds? */
93 	ds.stb1.st_mode = S_IFREG;
94 	if (blob1)
95 		ds.stb1.st_size = size1;
96 	ds.stb1.st_mtime = 0; /* XXX */
97 
98 	ds.stb2.st_mode = S_IFREG;
99 	if (blob2)
100 		ds.stb2.st_size = size2;
101 	ds.stb2.st_mtime = 0; /* XXX */
102 
103 	memset(&args, 0, sizeof(args));
104 	args.diff_format = D_UNIFIED;
105 	args.label[0] = label1 ? label1 : idstr1;
106 	args.label[1] = label2 ? label2 : idstr2;
107 	args.diff_context = diff_context;
108 	flags |= D_PROTOTYPE;
109 
110 	if (outfile) {
111 		fprintf(outfile, "blob - %s\n", idstr1);
112 		fprintf(outfile, "blob + %s\n", idstr2);
113 	}
114 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile, changes);
115 done:
116 	if (f1 && fclose(f1) != 0 && err == NULL)
117 		err = got_error_from_errno("fclose");
118 	if (f2 && fclose(f2) != 0 && err == NULL)
119 		err = got_error_from_errno("fclose");
120 	return err;
121 }
122 
123 const struct got_error *
124 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
125     struct got_blob_object *blob2, struct got_object_id *id1,
126     struct got_object_id *id2, const char *label1, const char *label2,
127     struct got_repository *repo)
128 {
129 	struct got_diff_blob_output_unidiff_arg *a = arg;
130 
131 	return diff_blobs(blob1, blob2, label1, label2, a->diff_context,
132 	    a->outfile, NULL);
133 }
134 
135 const struct got_error *
136 got_diff_blob(struct got_blob_object *blob1, struct got_blob_object *blob2,
137     const char *label1, const char *label2, int diff_context, FILE *outfile)
138 {
139 	return diff_blobs(blob1, blob2, label1, label2, diff_context, outfile,
140 	    NULL);
141 }
142 
143 const struct got_error *
144 got_diff_blob_file(struct got_blob_object *blob1, FILE *f2, size_t size2,
145     const char *label2, int diff_context, FILE *outfile)
146 {
147 	struct got_diff_state ds;
148 	struct got_diff_args args;
149 	const struct got_error *err = NULL;
150 	FILE *f1 = NULL;
151 	char hex1[SHA1_DIGEST_STRING_LENGTH];
152 	char *idstr1 = NULL;
153 	size_t size1;
154 	int res, flags = 0;
155 
156 	size1 = 0;
157 	if (blob1) {
158 		f1 = got_opentemp();
159 		if (f1 == NULL)
160 			return got_error_from_errno("got_opentemp");
161 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
162 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
163 		    blob1);
164 		if (err)
165 			goto done;
166 	} else {
167 		flags |= D_EMPTY1;
168 		idstr1 = "/dev/null";
169 	}
170 
171 	if (f2 == NULL)
172 		flags |= D_EMPTY2;
173 
174 	memset(&ds, 0, sizeof(ds));
175 	/* XXX should stat buffers be passed in args instead of ds? */
176 	ds.stb1.st_mode = S_IFREG;
177 	if (blob1)
178 		ds.stb1.st_size = size1;
179 	ds.stb1.st_mtime = 0; /* XXX */
180 
181 	ds.stb2.st_mode = S_IFREG;
182 	ds.stb2.st_size = size2;
183 	ds.stb2.st_mtime = 0; /* XXX */
184 
185 	memset(&args, 0, sizeof(args));
186 	args.diff_format = D_UNIFIED;
187 	args.label[0] = label2;
188 	args.label[1] = label2;
189 	args.diff_context = diff_context;
190 	flags |= D_PROTOTYPE;
191 
192 	fprintf(outfile, "blob - %s\n", idstr1);
193 	fprintf(outfile, "file + %s\n", f2 == NULL ? "/dev/null" : label2);
194 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile, NULL);
195 done:
196 	if (f1 && fclose(f1) != 0 && err == NULL)
197 		err = got_error_from_errno("fclose");
198 	return err;
199 }
200 
201 const struct got_error *
202 got_diff_blob_lines_changed(struct got_diff_changes **changes,
203     struct got_blob_object *blob1, struct got_blob_object *blob2)
204 {
205 	const struct got_error *err = NULL;
206 
207 	*changes = calloc(1, sizeof(**changes));
208 	if (*changes == NULL)
209 		return got_error_from_errno("calloc");
210 	SIMPLEQ_INIT(&(*changes)->entries);
211 
212 	err = diff_blobs(blob1, blob2, NULL, NULL, 3, NULL, *changes);
213 	if (err) {
214 		got_diff_free_changes(*changes);
215 		*changes = NULL;
216 	}
217 	return err;
218 }
219 
220 void
221 got_diff_free_changes(struct got_diff_changes *changes)
222 {
223 	struct got_diff_change *change;
224 	while (!SIMPLEQ_EMPTY(&changes->entries)) {
225 		change = SIMPLEQ_FIRST(&changes->entries);
226 		SIMPLEQ_REMOVE_HEAD(&changes->entries, entry);
227 		free(change);
228 	}
229 	free(changes);
230 }
231 
232 static const struct got_error *
233 diff_added_blob(struct got_object_id *id, const char *label,
234     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
235 {
236 	const struct got_error *err;
237 	struct got_blob_object  *blob = NULL;
238 	struct got_object *obj = NULL;
239 
240 	err = got_object_open(&obj, repo, id);
241 	if (err)
242 		return err;
243 
244 	err = got_object_blob_open(&blob, repo, obj, 8192);
245 	if (err)
246 		goto done;
247 	err = cb(cb_arg, NULL, blob, NULL, id, NULL, label, repo);
248 done:
249 	got_object_close(obj);
250 	if (blob)
251 		got_object_blob_close(blob);
252 	return err;
253 }
254 
255 static const struct got_error *
256 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
257     const char *label1, const char *label2, struct got_repository *repo,
258     got_diff_blob_cb cb, void *cb_arg)
259 {
260 	const struct got_error *err;
261 	struct got_object *obj1 = NULL;
262 	struct got_object *obj2 = NULL;
263 	struct got_blob_object *blob1 = NULL;
264 	struct got_blob_object *blob2 = NULL;
265 
266 	err = got_object_open(&obj1, repo, id1);
267 	if (err)
268 		return err;
269 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
270 		err = got_error(GOT_ERR_OBJ_TYPE);
271 		goto done;
272 	}
273 
274 	err = got_object_open(&obj2, repo, id2);
275 	if (err)
276 		goto done;
277 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
278 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
279 		goto done;
280 	}
281 
282 	err = got_object_blob_open(&blob1, repo, obj1, 8192);
283 	if (err)
284 		goto done;
285 
286 	err = got_object_blob_open(&blob2, repo, obj2, 8192);
287 	if (err)
288 		goto done;
289 
290 	err = cb(cb_arg, blob1, blob2, id1, id2, label1, label2, repo);
291 done:
292 	if (obj1)
293 		got_object_close(obj1);
294 	if (obj2)
295 		got_object_close(obj2);
296 	if (blob1)
297 		got_object_blob_close(blob1);
298 	if (blob2)
299 		got_object_blob_close(blob2);
300 	return err;
301 }
302 
303 static const struct got_error *
304 diff_deleted_blob(struct got_object_id *id, const char *label,
305     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
306 {
307 	const struct got_error *err;
308 	struct got_blob_object  *blob = NULL;
309 	struct got_object *obj = NULL;
310 
311 	err = got_object_open(&obj, repo, id);
312 	if (err)
313 		return err;
314 
315 	err = got_object_blob_open(&blob, repo, obj, 8192);
316 	if (err)
317 		goto done;
318 	err = cb(cb_arg, blob, NULL, id, NULL, label, NULL, repo);
319 done:
320 	got_object_close(obj);
321 	if (blob)
322 		got_object_blob_close(blob);
323 	return err;
324 }
325 
326 static const struct got_error *
327 diff_added_tree(struct got_object_id *id, const char *label,
328     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
329 {
330 	const struct got_error *err = NULL;
331 	struct got_object *treeobj = NULL;
332 	struct got_tree_object *tree = NULL;
333 
334 	err = got_object_open(&treeobj, repo, id);
335 	if (err)
336 		goto done;
337 
338 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
339 		err = got_error(GOT_ERR_OBJ_TYPE);
340 		goto done;
341 	}
342 
343 	err = got_object_tree_open(&tree, repo, treeobj);
344 	if (err)
345 		goto done;
346 
347 	err = got_diff_tree(NULL, tree, NULL, label, repo, cb, cb_arg);
348 done:
349 	if (tree)
350 		got_object_tree_close(tree);
351 	if (treeobj)
352 		got_object_close(treeobj);
353 	return err;
354 }
355 
356 static const struct got_error *
357 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
358     const char *label1, const char *label2, struct got_repository *repo,
359     got_diff_blob_cb cb, void *cb_arg)
360 {
361 	const struct got_error *err;
362 	struct got_object *treeobj1 = NULL;
363 	struct got_object *treeobj2 = NULL;
364 	struct got_tree_object *tree1 = NULL;
365 	struct got_tree_object *tree2 = NULL;
366 
367 	err = got_object_open(&treeobj1, repo, id1);
368 	if (err)
369 		goto done;
370 
371 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
372 		err = got_error(GOT_ERR_OBJ_TYPE);
373 		goto done;
374 	}
375 
376 	err = got_object_open(&treeobj2, repo, id2);
377 	if (err)
378 		goto done;
379 
380 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
381 		err = got_error(GOT_ERR_OBJ_TYPE);
382 		goto done;
383 	}
384 
385 	err = got_object_tree_open(&tree1, repo, treeobj1);
386 	if (err)
387 		goto done;
388 
389 	err = got_object_tree_open(&tree2, repo, treeobj2);
390 	if (err)
391 		goto done;
392 
393 	err = got_diff_tree(tree1, tree2, label1, label2, repo, cb, cb_arg);
394 
395 done:
396 	if (tree1)
397 		got_object_tree_close(tree1);
398 	if (tree2)
399 		got_object_tree_close(tree2);
400 	if (treeobj1)
401 		got_object_close(treeobj1);
402 	if (treeobj2)
403 		got_object_close(treeobj2);
404 	return err;
405 }
406 
407 static const struct got_error *
408 diff_deleted_tree(struct got_object_id *id, const char *label,
409     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
410 {
411 	const struct got_error *err;
412 	struct got_object *treeobj = NULL;
413 	struct got_tree_object *tree = NULL;
414 
415 	err = got_object_open(&treeobj, repo, id);
416 	if (err)
417 		goto done;
418 
419 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
420 		err = got_error(GOT_ERR_OBJ_TYPE);
421 		goto done;
422 	}
423 
424 	err = got_object_tree_open(&tree, repo, treeobj);
425 	if (err)
426 		goto done;
427 
428 	err = got_diff_tree(tree, NULL, label, NULL, repo, cb, cb_arg);
429 done:
430 	if (tree)
431 		got_object_tree_close(tree);
432 	if (treeobj)
433 		got_object_close(treeobj);
434 	return err;
435 }
436 
437 static const struct got_error *
438 diff_kind_mismatch(struct got_object_id *id1, struct got_object_id *id2,
439     const char *label1, const char *label2, struct got_repository *repo,
440     got_diff_blob_cb cb, void *cb_arg)
441 {
442 	/* XXX TODO */
443 	return NULL;
444 }
445 
446 static const struct got_error *
447 diff_entry_old_new(const struct got_tree_entry *te1,
448     const struct got_tree_entry *te2, const char *label1, const char *label2,
449     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
450 {
451 	const struct got_error *err = NULL;
452 	int id_match;
453 
454 	if (te2 == NULL) {
455 		if (S_ISDIR(te1->mode))
456 			err = diff_deleted_tree(te1->id, label1, repo,
457 			    cb, cb_arg);
458 		else
459 			err = diff_deleted_blob(te1->id, label1, repo,
460 			    cb, cb_arg);
461 		return err;
462 	}
463 
464 	id_match = (got_object_id_cmp(te1->id, te2->id) == 0);
465 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
466 		if (!id_match)
467 			return diff_modified_tree(te1->id, te2->id,
468 			    label1, label2, repo, cb, cb_arg);
469 	} else if (S_ISREG(te1->mode) && S_ISREG(te2->mode)) {
470 		if (!id_match)
471 			return diff_modified_blob(te1->id, te2->id,
472 			    label1, label2, repo, cb, cb_arg);
473 	}
474 
475 	if (id_match)
476 		return NULL;
477 
478 	return diff_kind_mismatch(te1->id, te2->id, label1, label2, repo,
479 	    cb, cb_arg);
480 }
481 
482 static const struct got_error *
483 diff_entry_new_old(const struct got_tree_entry *te2,
484     const struct got_tree_entry *te1, const char *label2,
485     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
486 {
487 	if (te1 != NULL) /* handled by diff_entry_old_new() */
488 		return NULL;
489 
490 	if (S_ISDIR(te2->mode))
491 		return diff_added_tree(te2->id, label2, repo, cb, cb_arg);
492 
493 	return diff_added_blob(te2->id, label2, repo, cb, cb_arg);
494 }
495 
496 const struct got_error *
497 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
498     const char *label1, const char *label2, struct got_repository *repo,
499     got_diff_blob_cb cb, void *cb_arg)
500 {
501 	const struct got_error *err = NULL;
502 	struct got_tree_entry *te1 = NULL;
503 	struct got_tree_entry *te2 = NULL;
504 	char *l1 = NULL, *l2 = NULL;
505 
506 	if (tree1) {
507 		const struct got_tree_entries *entries;
508 		entries = got_object_tree_get_entries(tree1);
509 		te1 = SIMPLEQ_FIRST(&entries->head);
510 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
511 		    te1->name) == -1)
512 			return got_error_from_errno("asprintf");
513 	}
514 	if (tree2) {
515 		const struct got_tree_entries *entries;
516 		entries = got_object_tree_get_entries(tree2);
517 		te2 = SIMPLEQ_FIRST(&entries->head);
518 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
519 		    te2->name) == -1)
520 			return got_error_from_errno("asprintf");
521 	}
522 
523 	do {
524 		if (te1) {
525 			const struct got_tree_entry *te = NULL;
526 			if (tree2)
527 				te = got_object_tree_find_entry(tree2,
528 				    te1->name);
529 			if (te) {
530 				free(l2);
531 				l2 = NULL;
532 				if (te && asprintf(&l2, "%s%s%s", label2,
533 				    label2[0] ? "/" : "", te->name) == -1)
534 					return
535 					    got_error_from_errno("asprintf");
536 			}
537 			err = diff_entry_old_new(te1, te, l1, l2, repo, cb,
538 			    cb_arg);
539 			if (err)
540 				break;
541 		}
542 
543 		if (te2) {
544 			const struct got_tree_entry *te = NULL;
545 			if (tree1)
546 				te = got_object_tree_find_entry(tree1,
547 				    te2->name);
548 			free(l2);
549 			if (te) {
550 				if (asprintf(&l2, "%s%s%s", label2,
551 				    label2[0] ? "/" : "", te->name) == -1)
552 					return
553 					    got_error_from_errno("asprintf");
554 			} else {
555 				if (asprintf(&l2, "%s%s%s", label2,
556 				    label2[0] ? "/" : "", te2->name) == -1)
557 					return
558 					    got_error_from_errno("asprintf");
559 			}
560 			err = diff_entry_new_old(te2, te, l2, repo, cb, cb_arg);
561 			if (err)
562 				break;
563 		}
564 
565 		free(l1);
566 		l1 = NULL;
567 		if (te1) {
568 			te1 = SIMPLEQ_NEXT(te1, entry);
569 			if (te1 &&
570 			    asprintf(&l1, "%s%s%s", label1,
571 			    label1[0] ? "/" : "", te1->name) == -1)
572 				return got_error_from_errno("asprintf");
573 		}
574 		free(l2);
575 		l2 = NULL;
576 		if (te2) {
577 			te2 = SIMPLEQ_NEXT(te2, entry);
578 			if (te2 &&
579 			    asprintf(&l2, "%s%s%s", label2,
580 			        label2[0] ? "/" : "", te2->name) == -1)
581 				return got_error_from_errno("asprintf");
582 		}
583 	} while (te1 || te2);
584 
585 	return err;
586 }
587 
588 const struct got_error *
589 got_diff_objects_as_blobs(struct got_object_id *id1, struct got_object_id *id2,
590     const char *label1, const char *label2, int diff_context,
591     struct got_repository *repo, FILE *outfile)
592 {
593 	const struct got_error *err;
594 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
595 
596 	if (id1 == NULL && id2 == NULL)
597 		return got_error(GOT_ERR_NO_OBJ);
598 
599 	if (id1) {
600 		err = got_object_open_as_blob(&blob1, repo, id1, 8192);
601 		if (err)
602 			goto done;
603 	}
604 	if (id2) {
605 		err = got_object_open_as_blob(&blob2, repo, id2, 8192);
606 		if (err)
607 			goto done;
608 	}
609 	err = got_diff_blob(blob1, blob2, label1, label2, diff_context,
610 	    outfile);
611 done:
612 	if (blob1)
613 		got_object_blob_close(blob1);
614 	if (blob2)
615 		got_object_blob_close(blob2);
616 	return err;
617 }
618 
619 const struct got_error *
620 got_diff_objects_as_trees(struct got_object_id *id1, struct got_object_id *id2,
621     char *label1, char *label2, int diff_context, struct got_repository *repo,
622     FILE *outfile)
623 {
624 	const struct got_error *err;
625 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
626 	struct got_diff_blob_output_unidiff_arg arg;
627 
628 	if (id1 == NULL && id2 == NULL)
629 		return got_error(GOT_ERR_NO_OBJ);
630 
631 	if (id1) {
632 		err = got_object_open_as_tree(&tree1, repo, id1);
633 		if (err)
634 			goto done;
635 	}
636 	if (id2) {
637 		err = got_object_open_as_tree(&tree2, repo, id2);
638 		if (err)
639 			goto done;
640 	}
641 	arg.diff_context = diff_context;
642 	arg.outfile = outfile;
643 	err = got_diff_tree(tree1, tree2, label1, label2, repo,
644 	    got_diff_blob_output_unidiff, &arg);
645 done:
646 	if (tree1)
647 		got_object_tree_close(tree1);
648 	if (tree2)
649 		got_object_tree_close(tree2);
650 	return err;
651 }
652 
653 const struct got_error *
654 got_diff_objects_as_commits(struct got_object_id *id1,
655     struct got_object_id *id2, int diff_context,
656     struct got_repository *repo, FILE *outfile)
657 {
658 	const struct got_error *err;
659 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
660 
661 	if (id2 == NULL)
662 		return got_error(GOT_ERR_NO_OBJ);
663 
664 	if (id1) {
665 		err = got_object_open_as_commit(&commit1, repo, id1);
666 		if (err)
667 			goto done;
668 	}
669 
670 	err = got_object_open_as_commit(&commit2, repo, id2);
671 	if (err)
672 		goto done;
673 
674 	err = got_diff_objects_as_trees(
675 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
676 	    got_object_commit_get_tree_id(commit2), "", "", diff_context, repo,
677 	    outfile);
678 done:
679 	if (commit1)
680 		got_object_commit_close(commit1);
681 	if (commit2)
682 		got_object_commit_close(commit2);
683 	return err;
684 }