find_pack_entry(): do not keep packed_git pointer locally

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.  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 <pclouds@gmail.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_file.c b/sha1_file.c
index 61e51edc42535689072e9919f1ffcc79be8f2bad..6b1b5125c8f992927b70ce10c43f2332f5948bc0 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -54,6 +54,8 @@ static struct cached_object empty_tree = {
        0
 };
 
+static struct packed_git *last_found_pack;
+
 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 (last_found_pack == p)
+                               last_found_pack = NULL;
                        free(p);
                        return;
                }
@@ -2046,27 +2050,22 @@ static int fill_pack_entry(const unsigned char *sha1,
 
 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;
 
        prepare_packed_git();
        if (!packed_git)
                return 0;
-       p = (last_found == (void *)1) ? packed_git : last_found;
 
-       do {
-               if (fill_pack_entry(sha1, e, p)) {
-                       last_found = p;
-                       return 1;
-               }
+       if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
+               return 1;
 
-               if (p == last_found)
-                       p = packed_git;
-               else
-                       p = p->next;
-               if (p == last_found)
-                       p = p->next;
-       } while (p);
+       for (p = packed_git; p; p = p->next) {
+               if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
+                       continue;
+
+               last_found_pack = p;
+               return 1;
+       }
        return 0;
 }