From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 16 Apr 2021 20:53:34 +0000 (-0700)
Subject: Merge branch 'ah/merge-ort-ubsan-fix'
X-Git-Tag: v2.32.0-rc0~76
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=257ae76ba9194c23a57a93033c499ee67bc1b037;p=thirdparty%2Fgit.git

Merge branch 'ah/merge-ort-ubsan-fix'

Code clean-up for merge-ort backend.

* ah/merge-ort-ubsan-fix:
  merge-ort: only do pointer arithmetic for non-empty lists
---

257ae76ba9194c23a57a93033c499ee67bc1b037
diff --cc merge-ort.c
index d1f4cf8a1f,3f55b438ec..b1795d838e
--- a/merge-ort.c
+++ b/merge-ort.c
@@@ -2653,23 -2491,14 +2653,15 @@@ static void write_tree(struct object_i
  		       size_t hash_size)
  {
  	size_t maxlen = 0, extra;
- 	unsigned int nr = versions->nr - offset;
+ 	unsigned int nr;
  	struct strbuf buf = STRBUF_INIT;
- 	struct string_list relevant_entries = STRING_LIST_INIT_NODUP;
  	int i;
  
- 	/*
- 	 * We want to sort the last (versions->nr-offset) entries in versions.
- 	 * Do so by abusing the string_list API a bit: make another string_list
- 	 * that contains just those entries and then sort them.
- 	 *
- 	 * We won't use relevant_entries again and will let it just pop off the
- 	 * stack, so there won't be allocation worries or anything.
- 	 */
- 	relevant_entries.items = versions->items + offset;
- 	relevant_entries.nr = versions->nr - offset;
- 	/* No need for STABLE_QSORT -- filenames must be unique */
- 	QSORT(relevant_entries.items, relevant_entries.nr, tree_entry_order);
+ 	assert(offset <= versions->nr);
+ 	nr = versions->nr - offset;
+ 	if (versions->nr)
++		/* No need for STABLE_QSORT -- filenames must be unique */
+ 		QSORT(versions->items + offset, nr, tree_entry_order);
  
  	/* Pre-allocate some space in buf */
  	extra = hash_size + 8; /* 8: 6 for mode, 1 for space, 1 for NUL char */