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[PATCH 05/16] clean up name allocation in prepare_revision_walk

From
Jeff King <peff@peff.net>
Date
Oct 3, 2014, 20:23 UTC
Message-ID
<20141003202356.GE16293@peff.net>
In-Reply-To
<20141003202045.GA15205@peff.net>

When we enter prepare_revision_walk, we have zero or more entries in our "pending" array. We disconnect that array from the rev_info, and then process each entry:

  1. If the entry is a commit and the --source option is in
     effect, we keep a pointer to the object name.
  2. Otherwise, we re-add the item to the pending list with
     a blank name.

We then throw away the old array by freeing the array itself, but do not touch the "name" field of each entry. For any items of type (2), we leak the memory associated with the name. This commit fixes that by calling object_array_clear, which handles the cleanup for us.

That breaks (1), though, because it depends on the memory pointed to by the name to last forever. We can solve that by making a copy of the name. This is slightly less efficient, but it shouldn't matter in practice, as we do it only for the tip commits of the traversal.

Signed-off-by: Jeff King <peff@peff.net>
---
 revision.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/revision.c b/revision.c
index e498b7c..01cc276 100644
--- a/revision.c
+++ b/revision.c
@@ -300,7 +300,7 @@ static struct commit *handle_commit(struct rev_info *revs,
 			revs->limited = 1;
 		}
 		if (revs->show_source && !commit->util)
-			commit->util = (void *) name;
+			commit->util = xstrdup(name);
 		return commit;
 	}
 
@@ -2656,15 +2656,16 @@ void reset_revision_walk(void)
 
 int prepare_revision_walk(struct rev_info *revs)
 {
-	int nr = revs->pending.nr;
-	struct object_array_entry *e, *list;
+	int i;
+	struct object_array old_pending;
 	struct commit_list **next = &revs->commits;
 
-	e = list = revs->pending.objects;
+	memcpy(&old_pending, &revs->pending, sizeof(old_pending));
 	revs->pending.nr = 0;
 	revs->pending.alloc = 0;
 	revs->pending.objects = NULL;
-	while (--nr >= 0) {
+	for (i = 0; i < old_pending.nr; i++) {
+		struct object_array_entry *e = old_pending.objects + i;
 		struct commit *commit = handle_commit(revs, e->item, e->name);
 		if (commit) {
 			if (!(commit->object.flags & SEEN)) {
@@ -2672,10 +2673,9 @@ int prepare_revision_walk(struct rev_info *revs)
 				next = commit_list_append(commit, next);
 			}
 		}
-		e++;
 	}
 	if (!revs->leak_pending)
-		free(list);
+		object_array_clear(&old_pending);
 
 	/* Signal whether we need per-parent treesame decoration */
 	if (revs->simplify_merges ||
-- 
2.1.1.566.gdb1f904
Previous: Jeff KingNext: Jeff King
Message 12 of 58 in “make prune mtime-checking more careful”
  1. 0/16 make prune mtime-checking more carefulJeff King, Oct 3, 2014
  2. 01/16 foreach_alt_odb: propagate return value from callbackJeff King, Oct 3, 2014
  3. René ScharfeOct 3, 2014
  4. Jeff KingOct 4, 2014
  5. 02/16 isxdigit: cast input to unsigned charJeff King, Oct 3, 2014
  6. 03/16 object_array: factor out slopbuf-freeing logicJeff King, Oct 3, 2014
  7. Michael HaggertyOct 7, 2014
  8. Jeff KingOct 8, 2014
  9. Michael HaggertyOct 8, 2014
  10. Jeff KingOct 8, 2014
  11. 04/16 object_array: add a "clear" functionJeff King, Oct 3, 2014
  12. 05/16 clean up name allocation in prepare_revision_walkJeff King, Oct 3, 2014
  13. 06/16 reachable: clear pending array after walking itJeff King, Oct 3, 2014
  14. 07/16 t5304: use test_path_is_* instead of "test -f"Jeff King, Oct 3, 2014
  15. Junio C HamanoOct 3, 2014
  16. 08/16 t5304: use helper to report failure of "test foo = bar"Jeff King, Oct 3, 2014
  17. Junio C HamanoOct 3, 2014
  18. Jeff KingOct 4, 2014
  19. Michael HaggertyOct 7, 2014
  20. Junio C HamanoOct 7, 2014
  21. Jeff KingOct 7, 2014
  22. Junio C HamanoOct 7, 2014
  23. Junio C HamanoOct 7, 2014
  24. Jeff KingOct 7, 2014
  25. Junio C HamanoOct 7, 2014
  26. Michael HaggertyOct 7, 2014
  27. Jeff KingOct 8, 2014
  28. Junio C HamanoOct 8, 2014
  29. 09/16 prune: factor out loose-object directory traversalJeff King, Oct 3, 2014
  30. Junio C HamanoOct 3, 2014
  31. Jeff KingOct 4, 2014
  32. Michael HaggertyOct 7, 2014
  33. Jeff KingOct 8, 2014
  34. 10/16 count-objects: do not use xsize_t when counting object sizeJeff King, Oct 3, 2014
  35. 11/16 count-objects: use for_each_loose_file_in_objdirJeff King, Oct 3, 2014
  36. 12/16 sha1_file: add for_each iterators for loose and packed objectsJeff King, Oct 3, 2014
  37. René ScharfeOct 5, 2014
  38. Ramsay JonesOct 5, 2014
  39. 13/16 prune: keep objects reachable from recent objectsJeff King, Oct 3, 2014
  40. Junio C HamanoOct 3, 2014
  41. Jeff KingOct 4, 2014
  42. Jeff KingOct 4, 2014
  43. Junio C HamanoOct 4, 2014
  44. Michael HaggertyOct 7, 2014
  45. Jeff KingOct 8, 2014
  46. Michael HaggertyOct 8, 2014
  47. 14/16 pack-objects: refactor unpack-unreachable expiration checkJeff King, Oct 3, 2014
  48. 15/16 pack-objects: match prune logic for discarding objectsJeff King, Oct 3, 2014
  49. 16/16 write_sha1_file: freshen existing objectsJeff King, Oct 3, 2014
  50. Junio C HamanoOct 3, 2014
  51. Jeff KingOct 4, 2014
  52. René ScharfeOct 5, 2014
  53. Junio C HamanoOct 3, 2014
  54. Junio C HamanoOct 4, 2014
  55. René ScharfeOct 5, 2014
  56. Jeff KingOct 6, 2014
  57. Jeff KingOct 8, 2014
  58. Junio C HamanoOct 8, 2014

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