Clear the delta base cache during fast-import checkpoint

Otherwise we may reuse the same memory address for a totally
different "struct packed_git", and a previously cached object from
the prior occupant might be returned when trying to unpack an object
from the new pack.

Found-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index 42f2f2754b93ff9d93883529778190d35a8ea43a..099a32e5fc536830fadc31cc68663ac3495a2a61 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -739,6 +739,7 @@ extern unsigned char* use_pack(struct packed_git *, struct pack_window **, off_t
 extern void close_pack_windows(struct packed_git *);
 extern void unuse_pack(struct pack_window **);
 extern void free_pack_by_name(const char *);
+extern void clear_delta_base_cache(void);
 extern struct packed_git *add_packed_git(const char *, int, int);
 extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t);
 extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t);

diff --git a/fast-import.c b/fast-import.c
index 6d5ee6f4636747d62abd06ae7a37dad8681beacc..5bc9ce2cc944d12914df0802fb4e010b056ed634 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -943,6 +943,7 @@ static void end_packfile(void)
 {
        struct packed_git *old_p = pack_data, *new_p;
 
+       clear_delta_base_cache();
        if (object_count) {
                char *idx_name;
                int i;

diff --git a/sha1_file.c b/sha1_file.c
index 0cfea9edc15402a38bbd195104c54e103b05f5a9..cbcae24d28f7000d2e55c4a2ef95026f07c5e5cc 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1630,6 +1630,13 @@ static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
        }
 }
 
+void clear_delta_base_cache(void)
+{
+       unsigned long p;
+       for (p = 0; p < MAX_DELTA_CACHE; p++)
+               release_delta_base_cache(&delta_base_cache[p]);
+}
+
 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
        void *base, unsigned long base_size, enum object_type type)
 {