[PATCH 2/6] find_pack_entry(): do not keep packed_git pointer locally

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Commit f7c22cc (always start looking up objects in the last used pack
first - 2007-05-30) introduce a static packed_git* pointer as an
optimization.

However keeping the pointer may become invalid if free_pack_by_name()
happens to free that particular pack.

Move the pointer out and reset the pointer in free_pack_by_name() if we
free it.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 sha1_file.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 3401301..155c808 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -53,6 +53,8 @@ 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;
@@ -719,6 +721,8 @@ 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;
 		}
@@ -2010,14 +2014,13 @@ static 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) {
@@ -2044,16 +2047,16 @@ 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;
-- 
1.7.4.74.g639db