1 /*
2  * Copyright (c) 2018, 2019, 2020 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/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/stdint.h>
21 
22 #include <limits.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sha1.h>
27 #include <zlib.h>
28 #include <ctype.h>
29 
30 #include "got_error.h"
31 #include "got_object.h"
32 #include "got_cancel.h"
33 #include "got_commit_graph.h"
34 #include "got_path.h"
35 
36 #include "got_lib_delta.h"
37 #include "got_lib_inflate.h"
38 #include "got_lib_object.h"
39 #include "got_lib_object_idset.h"
40 
41 struct got_commit_graph_node {
42 	struct got_object_id id;
43 
44 	/* Used only during iteration. */
45 	time_t timestamp;
46 	TAILQ_ENTRY(got_commit_graph_node) entry;
47 };
48 
49 TAILQ_HEAD(got_commit_graph_iter_list, got_commit_graph_node);
50 
51 struct got_commit_graph_branch_tip {
52 	struct got_object_id *commit_id;
53 	struct got_commit_object *commit;
54 	struct got_commit_graph_node *new_node;
55 };
56 
57 struct got_commit_graph {
58 	/* The set of all commits we have traversed. */
59 	struct got_object_idset *node_ids;
60 
61 	int flags;
62 #define GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL		0x01
63 
64 	/*
65 	 * A set of object IDs of known parent commits which we have not yet
66 	 * traversed. Each commit ID in this set represents a branch in commit
67 	 * history: Either the first-parent branch of the head node, or another
68 	 * branch corresponding to a traversed merge commit for which we have
69 	 * not traversed a branch point commit yet.
70 	 *
71 	 * Whenever we add a commit with a matching ID to the graph, we remove
72 	 * its corresponding element from this set, and add new elements for
73 	 * each of that commit's parent commits which were not traversed yet.
74 	 *
75 	 * When API users ask us to fetch more commits, we fetch commits from
76 	 * all currently open branches. This allows API users to process
77 	 * commits in linear order even though the history contains branches.
78 	 */
79 	struct got_object_idset *open_branches;
80 
81 	/* Array of branch tips for fetch_commits_from_open_branches(). */
82 	struct got_commit_graph_branch_tip *tips;
83 	int ntips;
84 
85 	/* Path of tree entry of interest to the API user. */
86 	char *path;
87 
88 	/*
89 	 * Nodes which will be passed to the API user next, sorted by
90 	 * commit timestmap.
91 	 */
92 	struct got_commit_graph_iter_list iter_list;
93 };
94 
95 static const struct got_error *
96 detect_changed_path(int *changed, struct got_commit_object *commit,
97     struct got_object_id *commit_id, const char *path,
98     struct got_repository *repo)
99 {
100 	const struct got_error *err = NULL;
101 	struct got_commit_object *pcommit = NULL;
102 	struct got_tree_object *tree = NULL, *ptree = NULL;
103 	struct got_object_qid *pid;
104 
105 	if (got_path_is_root_dir(path)) {
106 		*changed = 1;
107 		return NULL;
108 	}
109 
110 	*changed = 0;
111 
112 	pid = STAILQ_FIRST(&commit->parent_ids);
113 	if (pid == NULL) {
114 		struct got_object_id *obj_id;
115 		err = got_object_id_by_path(&obj_id, repo, commit, path);
116 		if (err) {
117 			if (err->code == GOT_ERR_NO_TREE_ENTRY)
118 				err = NULL;
119 		} else
120 			*changed = 1; /* The path was created in this commit. */
121 		free(obj_id);
122 		return err;
123 	}
124 
125 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
126 	if (err)
127 		return err;
128 
129 	err = got_object_open_as_commit(&pcommit, repo, &pid->id);
130 	if (err)
131 		goto done;
132 
133 	err = got_object_open_as_tree(&ptree, repo, pcommit->tree_id);
134 	if (err)
135 		goto done;
136 
137 	err = got_object_tree_path_changed(changed, tree, ptree, path, repo);
138 done:
139 	if (tree)
140 		got_object_tree_close(tree);
141 	if (ptree)
142 		got_object_tree_close(ptree);
143 	if (pcommit)
144 		got_object_commit_close(pcommit);
145 	return err;
146 }
147 
148 static void
149 add_node_to_iter_list(struct got_commit_graph *graph,
150     struct got_commit_graph_node *node, time_t committer_time)
151 {
152 	struct got_commit_graph_node *n, *next;
153 
154 	node->timestamp = committer_time;
155 
156 	n = TAILQ_FIRST(&graph->iter_list);
157 	while (n) {
158 		next = TAILQ_NEXT(n, entry);
159 		if (next && node->timestamp >= next->timestamp) {
160 			TAILQ_INSERT_BEFORE(next, node, entry);
161 			return;
162 		}
163 		n = next;
164 	}
165 	TAILQ_INSERT_TAIL(&graph->iter_list, node, entry);
166 }
167 
168 static const struct got_error *
169 add_node(struct got_commit_graph_node **new_node,
170     struct got_commit_graph *graph, struct got_object_id *commit_id,
171     struct got_repository *repo)
172 {
173 	const struct got_error *err = NULL;
174 	struct got_commit_graph_node *node;
175 
176 	*new_node = NULL;
177 
178 	node = calloc(1, sizeof(*node));
179 	if (node == NULL)
180 		return got_error_from_errno("calloc");
181 
182 	memcpy(&node->id, commit_id, sizeof(node->id));
183 	err = got_object_idset_add(graph->node_ids, &node->id, NULL);
184 	if (err)
185 		free(node);
186 	else
187 		*new_node = node;
188 	return err;
189 }
190 
191 /*
192  * Ask got-read-pack to traverse first-parent history until a commit is
193  * encountered which modified graph->path, or until the pack file runs
194  * out of relevant commits. This is faster than sending an individual
195  * request for each commit stored in the pack file.
196  */
197 static const struct got_error *
198 packed_first_parent_traversal(int *ncommits_traversed,
199     struct got_commit_graph *graph, struct got_object_id *commit_id,
200     struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id_queue traversed_commits;
204 	struct got_object_qid *qid;
205 
206 	STAILQ_INIT(&traversed_commits);
207 	*ncommits_traversed = 0;
208 
209 	err = got_traverse_packed_commits(&traversed_commits,
210 	    commit_id, graph->path, repo);
211 	if (err)
212 		return err;
213 
214 	/* Add all traversed commits to the graph... */
215 	STAILQ_FOREACH(qid, &traversed_commits, entry) {
216 		if (got_object_idset_contains(graph->open_branches, &qid->id))
217 			continue;
218 		if (got_object_idset_contains(graph->node_ids, &qid->id))
219 			continue;
220 
221 		(*ncommits_traversed)++;
222 
223 		/* ... except the last commit is the new branch tip. */
224 		if (STAILQ_NEXT(qid, entry) == NULL) {
225 			err = got_object_idset_add(graph->open_branches,
226 			    &qid->id, NULL);
227 			break;
228 		}
229 
230 		err = got_object_idset_add(graph->node_ids, &qid->id, NULL);
231 		if (err)
232 			break;
233 	}
234 
235 	got_object_id_queue_free(&traversed_commits);
236 	return err;
237 }
238 
239 static const struct got_error *
240 close_branch(struct got_commit_graph *graph, struct got_object_id *commit_id)
241 {
242 	const struct got_error *err;
243 
244 	err = got_object_idset_remove(NULL, graph->open_branches, commit_id);
245 	if (err && err->code != GOT_ERR_NO_OBJ)
246 		return err;
247 	return NULL;
248 }
249 
250 static const struct got_error *
251 advance_branch(struct got_commit_graph *graph, struct got_object_id *commit_id,
252     struct got_commit_object *commit, struct got_repository *repo)
253 {
254 	const struct got_error *err;
255 	struct got_object_qid *qid;
256 
257 	err = close_branch(graph, commit_id);
258 	if (err)
259 		return err;
260 
261 	if (graph->flags & GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL) {
262 		qid = STAILQ_FIRST(&commit->parent_ids);
263 		if (qid == NULL ||
264 		    got_object_idset_contains(graph->open_branches, &qid->id))
265 			return NULL;
266 		/*
267 		 * The root directory always changes by definition, and when
268 		 * logging the root we want to traverse consecutive commits
269 		 * even if they point at the same tree.
270 		 * But if we are looking for a specific path then we can avoid
271 		 * fetching packed commits which did not modify the path and
272 		 * only fetch their IDs. This speeds up 'got blame'.
273 		 */
274 		if (!got_path_is_root_dir(graph->path) &&
275 		    (commit->flags & GOT_COMMIT_FLAG_PACKED)) {
276 			int ncommits = 0;
277 			err = packed_first_parent_traversal(&ncommits,
278 			    graph, &qid->id, repo);
279 			if (err || ncommits > 0)
280 				return err;
281 		}
282 		return got_object_idset_add(graph->open_branches,
283 		    &qid->id, NULL);
284 	}
285 
286 	/*
287 	 * If we are graphing commits for a specific path, skip branches
288 	 * which do not contribute any content to this path.
289 	 */
290 	if (commit->nparents > 1 && !got_path_is_root_dir(graph->path)) {
291 		struct got_object_id *merged_id, *prev_id = NULL;
292 		int branches_differ = 0;
293 
294 		err = got_object_id_by_path(&merged_id, repo, commit,
295 		    graph->path);
296 		if (err)
297 			return err;
298 
299 		STAILQ_FOREACH(qid, &commit->parent_ids, entry) {
300 			struct got_object_id *id = NULL;
301 			struct got_commit_object *pcommit = NULL;
302 
303 			if (got_object_idset_contains(graph->open_branches,
304 			    &qid->id))
305 				continue;
306 
307 			err = got_object_open_as_commit(&pcommit, repo,
308 			    &qid->id);
309 			if (err) {
310 				free(merged_id);
311 				free(prev_id);
312 				return err;
313 			}
314 			err = got_object_id_by_path(&id, repo, pcommit,
315 			    graph->path);
316 			got_object_commit_close(pcommit);
317 			pcommit = NULL;
318 			if (err) {
319 				if (err->code == GOT_ERR_NO_TREE_ENTRY) {
320 					branches_differ = 1;
321 					continue;
322 				}
323 				free(merged_id);
324 				free(prev_id);
325 				return err;
326 			}
327 
328 			if (prev_id) {
329 				if (!branches_differ &&
330 				    got_object_id_cmp(id, prev_id) != 0)
331 					branches_differ = 1;
332 				free(prev_id);
333 			}
334 			prev_id = id;
335 
336 			/*
337 			 * If a branch has created the merged content we can
338 			 * skip any other branches.
339 			 */
340 			if (got_object_id_cmp(merged_id, id) == 0) {
341 				err = got_object_idset_add(graph->open_branches,
342 				    &qid->id, NULL);
343 				free(merged_id);
344 				free(id);
345 				return err;
346 			}
347 		}
348 
349 		free(prev_id);
350 		prev_id = NULL;
351 		free(merged_id);
352 		merged_id = NULL;
353 
354 		/*
355 		 * If the path's content is the same on all branches,
356 		 * follow the first parent only.
357 		 */
358 		if (!branches_differ) {
359 			qid = STAILQ_FIRST(&commit->parent_ids);
360 			if (qid == NULL)
361 				return NULL;
362 			if (got_object_idset_contains(graph->open_branches,
363 			    &qid->id))
364 				return NULL;
365 			if (got_object_idset_contains(graph->node_ids,
366 			    &qid->id))
367 				return NULL; /* parent already traversed */
368 			return got_object_idset_add(graph->open_branches,
369 			    &qid->id, NULL);
370 		}
371 	}
372 
373 	STAILQ_FOREACH(qid, &commit->parent_ids, entry) {
374 		if (got_object_idset_contains(graph->open_branches, &qid->id))
375 			continue;
376 		if (got_object_idset_contains(graph->node_ids, &qid->id))
377 			continue; /* parent already traversed */
378 		err = got_object_idset_add(graph->open_branches, &qid->id,
379 		    NULL);
380 		if (err)
381 			return err;
382 	}
383 
384 	return NULL;
385 }
386 
387 const struct got_error *
388 got_commit_graph_open(struct got_commit_graph **graph,
389     const char *path, int first_parent_traversal)
390 {
391 	const struct got_error *err = NULL;
392 
393 	*graph = calloc(1, sizeof(**graph));
394 	if (*graph == NULL)
395 		return got_error_from_errno("calloc");
396 
397 	TAILQ_INIT(&(*graph)->iter_list);
398 
399 	(*graph)->path = strdup(path);
400 	if ((*graph)->path == NULL) {
401 		err = got_error_from_errno("strdup");
402 		goto done;
403 	}
404 
405 	(*graph)->node_ids = got_object_idset_alloc();
406 	if ((*graph)->node_ids == NULL) {
407 		err = got_error_from_errno("got_object_idset_alloc");
408 		goto done;
409 	}
410 
411 	(*graph)->open_branches = got_object_idset_alloc();
412 	if ((*graph)->open_branches == NULL) {
413 		err = got_error_from_errno("got_object_idset_alloc");
414 		goto done;
415 	}
416 
417 	if (first_parent_traversal)
418 		(*graph)->flags |= GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL;
419 done:
420 	if (err) {
421 		got_commit_graph_close(*graph);
422 		*graph = NULL;
423 	}
424 	return err;
425 }
426 
427 struct add_branch_tip_arg {
428 	struct got_commit_graph_branch_tip *tips;
429 	int ntips;
430 	struct got_repository *repo;
431 	struct got_commit_graph *graph;
432 };
433 
434 static const struct got_error *
435 add_branch_tip(struct got_object_id *commit_id, void *data, void *arg)
436 {
437 	const struct got_error *err;
438 	struct add_branch_tip_arg *a = arg;
439 	struct got_commit_graph_node *new_node;
440 	struct got_commit_object *commit;
441 
442 	err = got_object_open_as_commit(&commit, a->repo, commit_id);
443 	if (err)
444 		return err;
445 
446 	err = add_node(&new_node, a->graph, commit_id, a->repo);
447 	if (err) {
448 		got_object_commit_close(commit);
449 		return err;
450 	}
451 
452 	a->tips[a->ntips].commit_id = &new_node->id;
453 	a->tips[a->ntips].commit = commit;
454 	a->tips[a->ntips].new_node = new_node;
455 	a->ntips++;
456 
457 	return NULL;
458 }
459 
460 static const struct got_error *
461 fetch_commits_from_open_branches(struct got_commit_graph *graph,
462     struct got_repository *repo, got_cancel_cb cancel_cb, void *cancel_arg)
463 {
464 	const struct got_error *err;
465 	struct add_branch_tip_arg arg;
466 	int i, ntips;
467 
468 	ntips = got_object_idset_num_elements(graph->open_branches);
469 	if (ntips == 0)
470 		return NULL;
471 
472 	/* (Re-)allocate branch tips array if necessary. */
473 	if (graph->ntips < ntips) {
474 		struct got_commit_graph_branch_tip *tips;
475 		tips = recallocarray(graph->tips, graph->ntips, ntips,
476 		    sizeof(*tips));
477 		if (tips == NULL)
478 			return got_error_from_errno("recallocarray");
479 		graph->tips = tips;
480 		graph->ntips = ntips;
481 	}
482 	arg.tips = graph->tips;
483 	arg.ntips = 0; /* add_branch_tip() will increment */
484 	arg.repo = repo;
485 	arg.graph = graph;
486 	err = got_object_idset_for_each(graph->open_branches, add_branch_tip,
487 	    &arg);
488 	if (err)
489 		goto done;
490 
491 	for (i = 0; i < arg.ntips; i++) {
492 		struct got_object_id *commit_id;
493 		struct got_commit_object *commit;
494 		struct got_commit_graph_node *new_node;
495 		int changed;
496 
497 		if (cancel_cb) {
498 			err = (*cancel_cb)(cancel_arg);
499 			if (err)
500 				break;
501 		}
502 
503 		commit_id = arg.tips[i].commit_id;
504 		commit = arg.tips[i].commit;
505 		new_node = arg.tips[i].new_node;
506 
507 		err = detect_changed_path(&changed, commit, commit_id,
508 		    graph->path, repo);
509 		if (err) {
510 			if (err->code != GOT_ERR_NO_OBJ)
511 				break;
512 			/*
513 			 * History of the path stops here on the current
514 			 * branch. Keep going on other branches.
515 			 */
516 			err = close_branch(graph, commit_id);
517 			if (err)
518 				break;
519 			continue;
520 		}
521 		if (changed) {
522 			add_node_to_iter_list(graph, new_node,
523 			    got_object_commit_get_committer_time(commit));
524 			arg.tips[i].new_node = NULL;
525 		}
526 		err = advance_branch(graph, commit_id, commit, repo);
527 		if (err)
528 			break;
529 	}
530 done:
531 	for (i = 0; i < arg.ntips; i++) {
532 		got_object_commit_close(arg.tips[i].commit);
533 		free(arg.tips[i].new_node);
534 	}
535 	return err;
536 }
537 
538 void
539 got_commit_graph_close(struct got_commit_graph *graph)
540 {
541 	struct got_commit_graph_node *node;
542 
543 	while ((node = TAILQ_FIRST(&graph->iter_list))) {
544 		TAILQ_REMOVE(&graph->iter_list, node, entry);
545 		free(node);
546 	}
547 
548 	if (graph->open_branches)
549 		got_object_idset_free(graph->open_branches);
550 	if (graph->node_ids)
551 		got_object_idset_free(graph->node_ids);
552 	free(graph->tips);
553 	free(graph->path);
554 	free(graph);
555 }
556 
557 const struct got_error *
558 got_commit_graph_iter_start(struct got_commit_graph *graph,
559     struct got_object_id *id, struct got_repository *repo,
560     got_cancel_cb cancel_cb, void *cancel_arg)
561 {
562 	const struct got_error *err = NULL;
563 
564 	if (!TAILQ_EMPTY(&graph->iter_list))
565 		return got_error(GOT_ERR_ITER_BUSY);
566 
567 	err = got_object_idset_add(graph->open_branches, id, NULL);
568 	if (err)
569 		return err;
570 
571 	/* Locate first commit which changed graph->path. */
572 	while (TAILQ_EMPTY(&graph->iter_list) &&
573 	    got_object_idset_num_elements(graph->open_branches) > 0) {
574 		err = fetch_commits_from_open_branches(graph, repo,
575 		    cancel_cb, cancel_arg);
576 		if (err)
577 			return err;
578 	}
579 
580 	if (TAILQ_EMPTY(&graph->iter_list)) {
581 		const char *path;
582 		if (got_path_is_root_dir(graph->path))
583 			return got_error_no_obj(id);
584 		path = graph->path;
585 		while (path[0] == '/')
586 			path++;
587 		return got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
588 	}
589 
590 	return NULL;
591 }
592 
593 const struct got_error *
594 got_commit_graph_iter_next(struct got_object_id *id,
595     struct got_commit_graph *graph, struct got_repository *repo,
596     got_cancel_cb cancel_cb, void *cancel_arg)
597 {
598 	const struct got_error *err = NULL;
599 	struct got_commit_graph_node *node;
600 
601 	node = TAILQ_FIRST(&graph->iter_list);
602 	if (node == NULL) {
603 		/* We are done iterating, or iteration was not started. */
604 		return got_error(GOT_ERR_ITER_COMPLETED);
605 	}
606 
607 	while (TAILQ_NEXT(node, entry) == NULL &&
608 	    got_object_idset_num_elements(graph->open_branches) > 0) {
609 		err = fetch_commits_from_open_branches(graph, repo,
610 		    cancel_cb, cancel_arg);
611 		if (err)
612 			return err;
613 	}
614 
615 	memcpy(id, &node->id, sizeof(*id));
616 
617 	TAILQ_REMOVE(&graph->iter_list, node, entry);
618 	free(node);
619 	return NULL;
620 }
621 
622 static const struct got_error *
623 find_yca_add_id(struct got_object_id **yca_id, struct got_commit_graph *graph,
624     struct got_object_idset *commit_ids, struct got_repository *repo,
625     got_cancel_cb cancel_cb, void *cancel_arg)
626 {
627 	const struct got_error *err = NULL;
628 	struct got_object_id id;
629 
630 	err = got_commit_graph_iter_next(&id, graph, repo, cancel_cb,
631 	    cancel_arg);
632 	if (err)
633 		return err;
634 
635 	if (got_object_idset_contains(commit_ids, &id)) {
636 		*yca_id = got_object_id_dup(&id);
637 		if (*yca_id == NULL)
638 			err = got_error_from_errno("got_object_id_dup");
639 		return err;
640 	}
641 
642 	return got_object_idset_add(commit_ids, &id, NULL);
643 }
644 
645 const struct got_error *
646 got_commit_graph_find_youngest_common_ancestor(struct got_object_id **yca_id,
647     struct got_object_id *commit_id, struct got_object_id *commit_id2,
648     int first_parent_traversal,
649     struct got_repository *repo, got_cancel_cb cancel_cb, void *cancel_arg)
650 {
651 	const struct got_error *err = NULL;
652 	struct got_commit_graph *graph = NULL, *graph2 = NULL;
653 	int completed = 0, completed2 = 0;
654 	struct got_object_idset *commit_ids;
655 
656 	*yca_id = NULL;
657 
658 	commit_ids = got_object_idset_alloc();
659 	if (commit_ids == NULL)
660 		return got_error_from_errno("got_object_idset_alloc");
661 
662 	err = got_commit_graph_open(&graph, "/", first_parent_traversal);
663 	if (err)
664 		goto done;
665 
666 	err = got_commit_graph_open(&graph2, "/", first_parent_traversal);
667 	if (err)
668 		goto done;
669 
670 	err = got_commit_graph_iter_start(graph, commit_id, repo,
671 	    cancel_cb, cancel_arg);
672 	if (err)
673 		goto done;
674 
675 	err = got_commit_graph_iter_start(graph2, commit_id2, repo,
676 	    cancel_cb, cancel_arg);
677 	if (err)
678 		goto done;
679 
680 	for (;;) {
681 		if (cancel_cb) {
682 			err = (*cancel_cb)(cancel_arg);
683 			if (err)
684 				break;
685 		}
686 
687 		if (!completed) {
688 			err = find_yca_add_id(yca_id, graph, commit_ids, repo,
689 			    cancel_cb, cancel_arg);
690 			if (err) {
691 				if (err->code != GOT_ERR_ITER_COMPLETED)
692 					break;
693 				err = NULL;
694 				completed = 1;
695 			}
696 			if (*yca_id)
697 				break;
698 		}
699 
700 		if (!completed2) {
701 			err = find_yca_add_id(yca_id, graph2, commit_ids, repo,
702 			    cancel_cb, cancel_arg);
703 			if (err) {
704 				if (err->code != GOT_ERR_ITER_COMPLETED)
705 					break;
706 				err = NULL;
707 				completed2 = 1;
708 			}
709 			if (*yca_id)
710 				break;
711 		}
712 
713 		if (completed && completed2) {
714 			err = got_error(GOT_ERR_ANCESTRY);
715 			break;
716 		}
717 	}
718 done:
719 	got_object_idset_free(commit_ids);
720 	if (graph)
721 		got_commit_graph_close(graph);
722 	if (graph2)
723 		got_commit_graph_close(graph2);
724 	return err;
725 }