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[PATCH 03/14] tree-diff: clear parent array in path_appendnew()

From
Jeff King <peff@peff.net>
Date
Jan 9, 2025, 08:33 UTC
Message-ID
<20250109083310.GC2748836@coredump.intra.peff.net>
In-Reply-To
<20250109082723.GA2748497@coredump.intra.peff.net>

All of the other functions which allocate a combine_diff_path struct zero out the parent array, but this code path does not. There's no bug, since our caller will fill in most of the fields. But leaving the unused fields (like combine_diff_parent.path) uninitialized makes working with the struct more error-prone than it needs to be.

Let's just zero the parent field to be consistent with the combine_diff_path_new() allocator.

Signed-off-by: Jeff King <peff@peff.net>
---
 tree-diff.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tree-diff.c b/tree-diff.c
index d9237ffd9b..24f7b5912c 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -151,8 +151,6 @@ static int emit_diff_first_parent_only(struct diff_options *opt, struct combine_
  *	process(p);
  *	p = pprev;
  *	; don't forget to free tail->next in the end
- *
- * p->parent[] remains uninitialized.
  */
 static struct combine_diff_path *path_appendnew(struct combine_diff_path *last,
 	int nparent, const struct strbuf *base, const char *path, int pathlen,
@@ -187,6 +185,8 @@ static struct combine_diff_path *path_appendnew(struct combine_diff_path *last,
 	p->mode = mode;
 	oidcpy(&p->oid, oid ? oid : null_oid());
 
+	memset(p->parent, 0, sizeof(p->parent[0]) * nparent);
+
 	return p;
 }
 
-- 
2.48.0.rc2.413.gc1c80375a3
Previous: Jeff KingNext: Junio C Hamano
Message 16 of 38 in “[BUGREPORT] git diff-tree --cc SEGFAUTs”
  1. Wink SavilleJan 3, 2025
  2. Jeff KingJan 3, 2025
  3. Wink SavilleJan 3, 2025
  4. Jeff KingJan 4, 2025
  5. Junio C HamanoJan 4, 2025
  6. Jeff KingJan 4, 2025
  7. Wink SavilleJan 4, 2025
  8. Wink SavilleJan 5, 2025
  9. 0/14 combine-diff cleanupsJeff King, Jan 9, 2025
  10. 01/14 run_diff_files(): delay allocation of combine_diff_pathJeff King, Jan 9, 2025
  11. Junio C HamanoJan 9, 2025
  12. 02/14 combine-diff: add combine_diff_path_new()Jeff King, Jan 9, 2025
  13. Junio C HamanoJan 9, 2025
  14. Patrick SteinhardtJan 13, 2025
  15. Jeff KingJan 14, 2025
  16. 03/14 tree-diff: clear parent array in path_appendnew()Jeff King, Jan 9, 2025
  17. Junio C HamanoJan 9, 2025
  18. Jeff KingJan 10, 2025
  19. 04/14 combine-diff: use pointer for parent pathsJeff King, Jan 9, 2025
  20. Junio C HamanoJan 9, 2025
  21. 05/14 diff: add a comment about combine_diff_path.parent.pathJeff King, Jan 9, 2025
  22. Patrick SteinhardtJan 13, 2025
  23. 06/14 run_diff_files(): de-mystify the size of combine_diff_path structJeff King, Jan 9, 2025
  24. Junio C HamanoJan 10, 2025
  25. 07/14 tree-diff: drop path_appendnew() alloc optimizationJeff King, Jan 9, 2025
  26. Patrick SteinhardtJan 13, 2025
  27. Jeff KingJan 14, 2025
  28. 08/14 tree-diff: pass whole path string to path_appendnew()Jeff King, Jan 9, 2025
  29. Patrick SteinhardtJan 13, 2025
  30. Jeff KingJan 14, 2025
  31. 09/14 tree-diff: inline path_appendnew()Jeff King, Jan 9, 2025
  32. Junio C HamanoJan 11, 2025
  33. 10/14 combine-diff: drop public declaration of combine_diff_path_size()Jeff King, Jan 9, 2025
  34. 11/14 tree-diff: drop list-tail argument to diff_tree_paths()Jeff King, Jan 9, 2025
  35. Junio C HamanoJan 18, 2025
  36. 12/14 tree-diff: use the name "tail" to refer to list tailJeff King, Jan 9, 2025
  37. 13/14 tree-diff: simplify emit_path() list managementJeff King, Jan 9, 2025
  38. 14/14 tree-diff: make list tail-passing more explicitJeff King, Jan 9, 2025

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