Subject: [PATCH] find_pack_entry(): do not keep packed_git pointer locally

From: Nguyễn Thái Ngọc Duy <[email-masked]>
Date: Mon, 30 Jan 2012 18:25:50 +0700

Commit f7c22cc (always start looking up objects in the last used pack
first - 2007-05-30) introduces a static packed_git* pointer as an
optimization.  The kept pointer however may become invalid if
free_pack_by_name() happens to free that particular pack.

Current code base does not access packs after calling
free_pack_by_name() so it should not be a problem. Anyway, move the
pointer out so that free_pack_by_name() can reset it to avoid running
into troubles in future.

Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
---
 sha1_file.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 88f2151..4ecc953 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -54,6 +54,8 @@ static struct cached_object empty_tree = {
 	0
 };
 
+static struct packed_git *find_pack_entry_last_found = (void *)1;
+
 static struct cached_object *find_cached_object(const unsigned char *sha1)
 {
 	int i;
@@ -720,6 +722,8 @@ void free_pack_by_name(const char *pack_name)
 			close_pack_index(p);
 			free(p->bad_object_sha1);
 			*pp = p->next;
+			if (find_pack_entry_last_found == p)
+				find_pack_entry_last_found = (void*)1;
 			free(p);
 			return;
 		}
@@ -2012,14 +2016,13 @@ int is_pack_valid(struct packed_git *p)
 
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 {
-	static struct packed_git *last_found = (void *)1;
 	struct packed_git *p;
 	off_t offset;
 
 	prepare_packed_git();
 	if (!packed_git)
 		return 0;
-	p = (last_found == (void *)1) ? packed_git : last_found;
+	p = (find_pack_entry_last_found == (void *)1) ? packed_git : find_pack_entry_last_found;
 
 	do {
 		if (p->num_bad_objects) {
@@ -2046,16 +2049,16 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 			e->offset = offset;
 			e->p = p;
 			hashcpy(e->sha1, sha1);
-			last_found = p;
+			find_pack_entry_last_found = p;
 			return 1;
 		}
 
 		next:
-		if (p == last_found)
+		if (p == find_pack_entry_last_found)
 			p = packed_git;
 		else
 			p = p->next;
-		if (p == last_found)
+		if (p == find_pack_entry_last_found)
 			p = p->next;
 	} while (p);
 	return 0;
-- 
1.7.8.36.g69ee2