1 /*
2  * Copyright (c) 2018 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 <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sha1.h>
26 #include <zlib.h>
27 #include <ctype.h>
28 
29 #include "got_error.h"
30 #include "got_object.h"
31 #include "got_cancel.h"
32 #include "got_commit_graph.h"
33 #include "got_path.h"
34 
35 #include "got_lib_delta.h"
36 #include "got_lib_inflate.h"
37 #include "got_lib_object.h"
38 #include "got_lib_object_idset.h"
39 
40 struct got_commit_graph_node {
41 	struct got_object_id id;
42 	time_t timestamp;
43 
44 	/* Used during graph iteration. */
45 	TAILQ_ENTRY(got_commit_graph_node) entry;
46 };
47 
48 TAILQ_HEAD(got_commit_graph_iter_list, got_commit_graph_node);
49 
50 struct got_commit_graph_branch_tip {
51 	struct got_object_id *commit_id;
52 	struct got_commit_object *commit;
53 	struct got_commit_graph_node *new_node;
54 	int changed;
55 	int branch_done;
56 };
57 
58 struct got_commit_graph {
59 	/* The set of all commits we have traversed. */
60 	struct got_object_idset *node_ids;
61 
62 	/* The commit at which traversal began (youngest commit in node_ids). */
63 	struct got_commit_graph_node *head_node;
64 
65 	int flags;
66 #define GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL		0x01
67 
68 	/*
69 	 * A set of object IDs of known parent commits which we have not yet
70 	 * traversed. Each commit ID in this set represents a branch in commit
71 	 * history: Either the first-parent branch of the head node, or another
72 	 * branch corresponding to a traversed merge commit for which we have
73 	 * not traversed a branch point commit yet.
74 	 *
75 	 * Whenever we add a commit with a matching ID to the graph, we remove
76 	 * its corresponding element from this set, and add new elements for
77 	 * each of that commit's parent commits which were not traversed yet.
78 	 *
79 	 * When API users ask us to fetch more commits, we fetch commits from
80 	 * all currently open branches. This allows API users to process
81 	 * commits in linear order even though the history contains branches.
82 	 */
83 	struct got_object_idset *open_branches;
84 
85 	/* Array of branch tips for fetch_commits_from_open_branches(). */
86 	struct got_commit_graph_branch_tip *tips;
87 	int ntips;
88 
89 	/* Path of tree entry of interest to the API user. */
90 	char *path;
91 
92 	/* The next commit to return when the API user asks for one. */
93 	struct got_commit_graph_node *iter_node;
94 
95 	/* The graph iteration list contains all nodes in sorted order. */
96 	struct got_commit_graph_iter_list iter_list;
97 };
98 
99 static struct got_commit_graph *
100 alloc_graph(const char *path)
101 {
102 	struct got_commit_graph *graph;
103 
104 	graph = calloc(1, sizeof(*graph));
105 	if (graph == NULL)
106 		return NULL;
107 
108 	graph->path = strdup(path);
109 	if (graph->path == NULL) {
110 		free(graph);
111 		return NULL;
112 	}
113 
114 	graph->node_ids = got_object_idset_alloc();
115 	if (graph->node_ids == NULL) {
116 		free(graph->path);
117 		free(graph);
118 		return NULL;
119 	}
120 
121 	graph->open_branches = got_object_idset_alloc();
122 	if (graph->open_branches == NULL) {
123 		got_object_idset_free(graph->node_ids);
124 		free(graph->path);
125 		free(graph);
126 		return NULL;
127 	}
128 
129 	TAILQ_INIT(&graph->iter_list);
130 	return graph;
131 }
132 
133 static const struct got_error *
134 detect_changed_path(int *changed, struct got_commit_object *commit,
135     struct got_object_id *commit_id, const char *path,
136     struct got_repository *repo)
137 {
138 	const struct got_error *err = NULL;
139 	struct got_commit_object *pcommit = NULL;
140 	struct got_tree_object *tree = NULL, *ptree = NULL;
141 	struct got_object_qid *pid;
142 
143 	if (got_path_is_root_dir(path)) {
144 		*changed = 1;
145 		return NULL;
146 	}
147 
148 	*changed = 0;
149 
150 	pid = SIMPLEQ_FIRST(&commit->parent_ids);
151 	if (pid == NULL) {
152 		struct got_object_id *obj_id;
153 		err = got_object_id_by_path(&obj_id, repo, commit_id, path);
154 		if (err) {
155 			if (err->code == GOT_ERR_NO_TREE_ENTRY)
156 				err = NULL;
157 		} else
158 			*changed = 1; /* The path was created in this commit. */
159 		free(obj_id);
160 		return err;
161 	}
162 
163 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
164 	if (err)
165 		return err;
166 
167 	err = got_object_open_as_commit(&pcommit, repo, pid->id);
168 	if (err)
169 		goto done;
170 
171 	err = got_object_open_as_tree(&ptree, repo, pcommit->tree_id);
172 	if (err)
173 		goto done;
174 
175 	err = got_object_tree_path_changed(changed, tree, ptree, path, repo);
176 done:
177 	if (tree)
178 		got_object_tree_close(tree);
179 	if (ptree)
180 		got_object_tree_close(ptree);
181 	if (pcommit)
182 		got_object_commit_close(pcommit);
183 	return err;
184 }
185 
186 static void
187 add_node_to_iter_list(struct got_commit_graph *graph,
188     struct got_commit_graph_node *node,
189     struct got_commit_graph_node *child_node)
190 {
191 	struct got_commit_graph_node *n, *next;
192 
193 	if (TAILQ_EMPTY(&graph->iter_list)) {
194 		TAILQ_INSERT_HEAD(&graph->iter_list, node, entry);
195 		graph->iter_node = node;
196 		return;
197 	}
198 
199 	n = graph->iter_node;
200 	/* Ensure that an iteration in progress will see this new commit. */
201 	while (n) {
202 		next = TAILQ_NEXT(n, entry);
203 		if (next && node->timestamp >= next->timestamp) {
204 			TAILQ_INSERT_BEFORE(next, node, entry);
205 			return;
206 		}
207 		n = next;
208 	}
209 	TAILQ_INSERT_TAIL(&graph->iter_list, node, entry);
210 }
211 
212 static const struct got_error *
213 close_branch(struct got_commit_graph *graph, struct got_object_id *commit_id)
214 {
215 	const struct got_error *err;
216 
217 	err = got_object_idset_remove(NULL, graph->open_branches, commit_id);
218 	if (err && err->code != GOT_ERR_NO_OBJ)
219 		return err;
220 	return NULL;
221 }
222 
223 static const struct got_error *
224 advance_branch(struct got_commit_graph *graph,
225     struct got_commit_graph_node *node,
226     struct got_object_id *commit_id, struct got_commit_object *commit,
227     struct got_repository *repo)
228 {
229 	const struct got_error *err;
230 	struct got_object_qid *qid;
231 
232 	err = close_branch(graph, commit_id);
233 	if (err)
234 		return err;
235 
236 	if (graph->flags & GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL) {
237 		qid = SIMPLEQ_FIRST(&commit->parent_ids);
238 		if (qid == NULL ||
239 		    got_object_idset_get(graph->open_branches, qid->id))
240 			return NULL;
241 		return got_object_idset_add(graph->open_branches,
242 		    qid->id, node);
243 	}
244 
245 	/*
246 	 * If we are graphing commits for a specific path, skip branches
247 	 * which do not contribute any content to this path.
248 	 */
249 	if (commit->nparents > 1 && !got_path_is_root_dir(graph->path)) {
250 		struct got_object_id *merged_id, *prev_id = NULL;
251 		int branches_differ = 0;
252 
253 		err = got_object_id_by_path(&merged_id, repo, commit_id,
254 		    graph->path);
255 		if (err)
256 			return err;
257 
258 		SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
259 			struct got_object_id *id;
260 
261 			if (got_object_idset_get(graph->open_branches, qid->id))
262 				continue;
263 
264 			err = got_object_id_by_path(&id, repo, qid->id,
265 			    graph->path);
266 			if (err) {
267 				if (err->code == GOT_ERR_NO_TREE_ENTRY) {
268 					branches_differ = 1;
269 					continue;
270 				}
271 				free(merged_id);
272 				free(prev_id);
273 				return err;
274 			}
275 
276 			if (prev_id) {
277 				if (!branches_differ &&
278 				    got_object_id_cmp(id, prev_id) != 0)
279 					branches_differ = 1;
280 				free(prev_id);
281 			}
282 			prev_id = id;
283 
284 			/*
285 			 * If a branch has created the merged content we can
286 			 * skip any other branches.
287 			 */
288 			if (got_object_id_cmp(merged_id, id) == 0) {
289 				err = got_object_idset_add(graph->open_branches,
290 				    qid->id, node);
291 				free(merged_id);
292 				free(id);
293 				return err;
294 			}
295 		}
296 
297 		free(prev_id);
298 		prev_id = NULL;
299 		free(merged_id);
300 		merged_id = NULL;
301 
302 		/*
303 		 * If the path's content is the same on all branches,
304 		 * follow the first parent only.
305 		 */
306 		if (!branches_differ) {
307 			qid = SIMPLEQ_FIRST(&commit->parent_ids);
308 			if (qid == NULL)
309 				return NULL;
310 			if (got_object_idset_get(graph->open_branches, qid->id))
311 				return NULL;
312 			if (got_object_idset_get(graph->node_ids, qid->id))
313 				return NULL; /* parent already traversed */
314 			return got_object_idset_add(graph->open_branches,
315 			    qid->id, node);
316 		}
317 	}
318 
319 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
320 		if (got_object_idset_get(graph->open_branches, qid->id))
321 			continue;
322 		if (got_object_idset_get(graph->node_ids, qid->id))
323 			continue; /* parent already traversed */
324 		err = got_object_idset_add(graph->open_branches, qid->id, node);
325 		if (err)
326 			return err;
327 	}
328 
329 	return NULL;
330 }
331 
332 static const struct got_error *
333 add_node(struct got_commit_graph_node **new_node, int *changed,
334     int *branch_done, struct got_commit_graph *graph,
335     struct got_object_id *commit_id, struct got_commit_object *commit,
336     struct got_commit_graph_node *child_node, struct got_repository *repo)
337 {
338 	const struct got_error *err = NULL;
339 	struct got_commit_graph_node *node;
340 
341 	*new_node = NULL;
342 	*changed = 0;
343 	*branch_done = 0;
344 
345 	node = calloc(1, sizeof(*node));
346 	if (node == NULL)
347 		return got_error_from_errno("calloc");
348 
349 	memcpy(&node->id, commit_id, sizeof(node->id));
350 	node->timestamp = commit->committer_time;
351 
352 	err = got_object_idset_add(graph->node_ids, &node->id, node);
353 	if (err) {
354 		free(node);
355 		return err;
356 	}
357 
358 	err = detect_changed_path(changed, commit, commit_id, graph->path,
359 	    repo);
360 	if (err) {
361 		if (err->code == GOT_ERR_NO_OBJ) {
362 			/*
363 			 * History of the path stops here on the current
364 			 * branch. Keep going on other branches.
365 			 */
366 			err = NULL;
367 			*branch_done = 1;
368 		} else {
369 			got_object_idset_remove(NULL, graph->node_ids,
370 			    &node->id);
371 			free(node);
372 			return err;
373 		}
374 	}
375 
376 	if (*changed)
377 		add_node_to_iter_list(graph, node, child_node);
378 	*new_node = node;
379 	return NULL;
380 }
381 
382 const struct got_error *
383 got_commit_graph_open(struct got_commit_graph **graph,
384     struct got_object_id *commit_id, const char *path,
385     int first_parent_traversal, struct got_repository *repo)
386 {
387 	const struct got_error *err = NULL;
388 	struct got_commit_object *commit;
389 	int changed, branch_done;
390 
391 	*graph = NULL;
392 
393 	err = got_object_open_as_commit(&commit, repo, commit_id);
394 	if (err)
395 		return err;
396 
397 	/* The path must exist in our initial commit. */
398 	if (!got_path_is_root_dir(path)) {
399 		struct got_object_id *obj_id;
400 		err = got_object_id_by_path(&obj_id, repo, commit_id, path);
401 		if (err)
402 			return err;
403 		free(obj_id);
404 	}
405 
406 	*graph = alloc_graph(path);
407 	if (*graph == NULL) {
408 		err = got_error_from_errno("alloc_graph");
409 		got_object_commit_close(commit);
410 		return err;
411 	}
412 
413 	if (first_parent_traversal)
414 		(*graph)->flags |= GOT_COMMIT_GRAPH_FIRST_PARENT_TRAVERSAL;
415 
416 	err = add_node(&(*graph)->head_node, &changed, &branch_done, *graph,
417 	    commit_id, commit, NULL, repo);
418 	if (err == NULL) {
419 		err = advance_branch(*graph, (*graph)->head_node, commit_id,
420 		    commit, repo);
421 	}
422 	got_object_commit_close(commit);
423 	if (err) {
424 		got_commit_graph_close(*graph);
425 		*graph = NULL;
426 		return err;
427 	}
428 	
429 	return NULL;
430 }
431 
432 struct add_branch_tip_arg {
433 	struct got_commit_graph_branch_tip *tips;
434 	int ntips;
435 	struct got_repository *repo;
436 	struct got_commit_graph *graph;
437 };
438 
439 static const struct got_error *
440 add_branch_tip(struct got_object_id *commit_id, void *data, void *arg)
441 {
442 	const struct got_error *err;
443 	struct got_commit_graph_node *child_node = data;
444 	struct add_branch_tip_arg *a = arg;
445 	struct got_commit_graph_node *new_node;
446 	struct got_commit_object *commit;
447 	int changed, branch_done;
448 
449 	err = got_object_open_as_commit(&commit, a->repo, commit_id);
450 	if (err)
451 		return err;
452 
453 	err = add_node(&new_node, &changed, &branch_done, a->graph,
454 	    commit_id, commit, child_node, a->repo);
455 	if (err)
456 		return err;
457 
458 	a->tips[a->ntips].commit_id = new_node ? &new_node->id : NULL;
459 	a->tips[a->ntips].commit = commit;
460 	a->tips[a->ntips].new_node = new_node;
461 	a->tips[a->ntips].changed = changed;
462 	a->tips[a->ntips].branch_done = branch_done;
463 	a->ntips++;
464 
465 	return NULL;
466 }
467 
468 static const struct got_error *
469 fetch_commits_from_open_branches(int *nfetched,
470     struct got_object_id **changed_id, struct got_commit_graph *graph,
471     struct got_repository *repo, got_cancel_cb cancel_cb, void *cancel_arg)
472 {
473 	const struct got_error *err;
474 	struct add_branch_tip_arg arg;
475 	int i, ntips;
476 
477 	*nfetched = 0;
478 	if (changed_id)
479 		*changed_id = NULL;
480 
481 	ntips = got_object_idset_num_elements(graph->open_branches);
482 	if (ntips == 0)
483 		return NULL;
484 
485 	/* (Re-)allocate branch tips array if necessary. */
486 	if (graph->ntips < ntips) {
487 		struct got_commit_graph_branch_tip *tips;
488 		tips = recallocarray(graph->tips, graph->ntips, ntips,
489 		    sizeof(*tips));
490 		if (tips == NULL)
491 			return got_error_from_errno("recallocarray");
492 		graph->tips = tips;
493 		graph->ntips = ntips;
494 	}
495 	arg.tips = graph->tips;
496 	arg.ntips = 0; /* add_branch_tip() will increment */
497 	arg.repo = repo;
498 	arg.graph = graph;
499 	err = got_object_idset_for_each(graph->open_branches, add_branch_tip,
500 	    &arg);
501 	if (err)
502 		goto done;
503 
504 	for (i = 0; i < arg.ntips; i++) {
505 		struct got_object_id *commit_id;
506 		struct got_commit_object *commit;
507 		struct got_commit_graph_node *new_node;
508 		int branch_done, changed;
509 
510 		if (cancel_cb) {
511 			err = (*cancel_cb)(cancel_arg);
512 			if (err)
513 				break;
514 		}
515 
516 		commit_id = arg.tips[i].commit_id;
517 		commit = arg.tips[i].commit;
518 		new_node = arg.tips[i].new_node;
519 		branch_done = arg.tips[i].branch_done;
520 		changed = arg.tips[i].changed;
521 
522 		if (branch_done)
523 			err = close_branch(graph, commit_id);
524 		else
525 			err = advance_branch(graph, new_node, commit_id,
526 			    commit, repo);
527 		if (err)
528 			break;
529 		if (changed && changed_id && *changed_id == NULL)
530 			*changed_id = commit_id;
531 	}
532 done:
533 	for (i = 0; i < arg.ntips; i++)
534 		got_object_commit_close(arg.tips[i].commit);
535 	(*nfetched) = arg.ntips;
536 	return err;
537 }
538 
539 const struct got_error *
540 got_commit_graph_fetch_commits(struct got_commit_graph *graph, int limit,
541     struct got_repository *repo, got_cancel_cb cancel_cb, void *cancel_arg)
542 {
543 	const struct got_error *err;
544 	int nfetched = 0, ncommits;
545 	struct got_object_id *changed_id = NULL;
546 
547 	while (nfetched < limit) {
548 		if (cancel_cb) {
549 			err = (*cancel_cb)(cancel_arg);
550 			if (err)
551 				return err;
552 		}
553 		err = fetch_commits_from_open_branches(&ncommits,
554 		    &changed_id, graph, repo, cancel_cb, cancel_arg);
555 		if (err)
556 			return err;
557 		if (ncommits == 0)
558 			break;
559 		if (changed_id)
560 			nfetched += ncommits;
561 	}
562 
563 	return NULL;
564 }
565 
566 static const struct got_error *
567 free_node_iter(struct got_object_id *id, void *data, void *arg)
568 {
569 	struct got_commit_graph_node *node = data;
570 	free(node);
571 	return NULL;
572 }
573 
574 void
575 got_commit_graph_close(struct got_commit_graph *graph)
576 {
577 	got_object_idset_free(graph->open_branches);
578 	got_object_idset_for_each(graph->node_ids, free_node_iter, NULL);
579 	got_object_idset_free(graph->node_ids);
580 	free(graph->tips);
581 	free(graph->path);
582 	free(graph);
583 }
584 
585 const struct got_error *
586 got_commit_graph_iter_start(struct got_commit_graph *graph,
587     struct got_object_id *id, struct got_repository *repo,
588     got_cancel_cb cancel_cb, void *cancel_arg)
589 {
590 	const struct got_error *err = NULL;
591 	struct got_commit_graph_node *start_node;
592 	struct got_commit_object *commit;
593 	int changed;
594 
595 	start_node = got_object_idset_get(graph->node_ids, id);
596 	while (start_node == NULL) {
597 		int ncommits;
598 		err = fetch_commits_from_open_branches(&ncommits, NULL, graph,
599 		    repo, cancel_cb, cancel_arg);
600 		if (err)
601 			return err;
602 		if (ncommits == 0)
603 			return got_error_no_obj(id);
604 		start_node = got_object_idset_get(graph->node_ids, id);
605 	}
606 
607 	err = got_object_open_as_commit(&commit, repo, &start_node->id);
608 	if (err)
609 		return err;
610 
611 	err = detect_changed_path(&changed, commit, &start_node->id,
612 	    graph->path, repo);
613 	if (err) {
614 		got_object_commit_close(commit);
615 		return err;
616 	}
617 
618 	if (!changed) {
619 		/* Locate first commit which changed graph->path. */
620 		struct got_object_id *changed_id = NULL;
621 		while (changed_id == NULL) {
622 			int ncommits;
623 			err = fetch_commits_from_open_branches(&ncommits,
624 			    &changed_id, graph, repo, cancel_cb, cancel_arg);
625 			if (err) {
626 				got_object_commit_close(commit);
627 				return err;
628 			}
629 		}
630 		start_node = got_object_idset_get(graph->node_ids, changed_id);
631 	}
632 	got_object_commit_close(commit);
633 
634 	graph->iter_node = start_node;
635 	return NULL;
636 }
637 
638 const struct got_error *
639 got_commit_graph_iter_next(struct got_object_id **id,
640     struct got_commit_graph *graph)
641 {
642 	*id = NULL;
643 
644 	if (graph->iter_node == NULL) {
645 		/* We are done iterating, or iteration was not started. */
646 		return got_error(GOT_ERR_ITER_COMPLETED);
647 	}
648 
649 	if (graph->iter_node ==
650 	    TAILQ_LAST(&graph->iter_list, got_commit_graph_iter_list) &&
651 	    got_object_idset_num_elements(graph->open_branches) == 0) {
652 		/* We are done iterating. */
653 		*id = &graph->iter_node->id;
654 		graph->iter_node = NULL;
655 		return NULL;
656 	}
657 
658 	if (TAILQ_NEXT(graph->iter_node, entry) == NULL)
659 		return got_error(GOT_ERR_ITER_NEED_MORE);
660 
661 	*id = &graph->iter_node->id;
662 	graph->iter_node = TAILQ_NEXT(graph->iter_node, entry);
663 	return NULL;
664 }
665 
666 const struct got_error *
667 got_commit_graph_find_youngest_common_ancestor(struct got_object_id **yca_id,
668     struct got_object_id *commit_id, struct got_object_id *commit_id2,
669     struct got_repository *repo, got_cancel_cb cancel_cb, void *cancel_arg)
670 {
671 	const struct got_error *err = NULL;
672 	struct got_commit_graph *graph = NULL, *graph2 = NULL;
673 	int completed = 0, completed2 = 0;
674 	struct got_object_idset *commit_ids;
675 
676 	*yca_id = NULL;
677 
678 	commit_ids = got_object_idset_alloc();
679 	if (commit_ids == NULL)
680 		return got_error_from_errno("got_object_idset_alloc");
681 
682 	err = got_commit_graph_open(&graph, commit_id, "/", 1, repo);
683 	if (err)
684 		goto done;
685 
686 	err = got_commit_graph_open(&graph2, commit_id2, "/", 1, repo);
687 	if (err)
688 		goto done;
689 
690 	err = got_commit_graph_iter_start(graph, commit_id, repo,
691 	    cancel_cb, cancel_arg);
692 	if (err)
693 		goto done;
694 
695 	err = got_commit_graph_iter_start(graph2, commit_id2, repo,
696 	    cancel_cb, cancel_arg);
697 	if (err)
698 		goto done;
699 
700 	for (;;) {
701 		struct got_object_id *id, *id2;
702 
703 		if (cancel_cb) {
704 			err = (*cancel_cb)(cancel_arg);
705 			if (err)
706 				break;
707 		}
708 
709 		if (!completed) {
710 			err = got_commit_graph_iter_next(&id, graph);
711 			if (err) {
712 				if (err->code == GOT_ERR_ITER_COMPLETED)
713 					completed = 1;
714 				else if (err->code != GOT_ERR_ITER_NEED_MORE)
715 					break;
716 				err = got_commit_graph_fetch_commits(graph, 1,
717 				    repo, cancel_cb, cancel_arg);
718 				if (err)
719 					break;
720 			}
721 		}
722 
723 		if (!completed2) {
724 			err = got_commit_graph_iter_next(&id2, graph2);
725 			if (err) {
726 				if (err->code == GOT_ERR_ITER_COMPLETED)
727 					completed2 = 1;
728 				else if (err->code != GOT_ERR_ITER_NEED_MORE)
729 					break;
730 				err = got_commit_graph_fetch_commits(graph2, 1,
731 				    repo, cancel_cb, cancel_arg);
732 				if (err)
733 					break;
734 			}
735 		}
736 
737 		if (id) {
738 			if (got_object_idset_get(commit_ids, id)) {
739 				*yca_id = got_object_id_dup(id);
740 				if (*yca_id)
741 					break;
742 				err = got_error_from_errno("got_object_id_dup");
743 				break;
744 
745 			}
746 			err = got_object_idset_add(commit_ids, id, id);
747 			if (err)
748 				break;
749 		}
750 		if (id2) {
751 			if (got_object_idset_get(commit_ids, id2)) {
752 				*yca_id = got_object_id_dup(id2);
753 				if (*yca_id)
754 					break;
755 				err = got_error_from_errno("got_object_id_dup");
756 				break;
757 
758 			}
759 			err = got_object_idset_add(commit_ids, id2, id2);
760 			if (err)
761 				break;
762 		}
763 
764 		if (completed && completed2) {
765 			err = got_error(GOT_ERR_ANCESTRY);
766 			break;
767 		}
768 
769 	}
770 done:
771 	got_object_idset_free(commit_ids);
772 	if (graph)
773 		got_commit_graph_close(graph);
774 	if (graph2)
775 		got_commit_graph_close(graph2);
776 	return err;
777 }