make sure packs to be replaced are closed beforehand

Especially on Windows where an opened file cannot be replaced, make
sure pack-objects always close packs it is about to replace. Even on
non Windows systems, this could save potential bad results if ever
objects were to be read from the new pack file using offset from the old
index.

This should fix t5303 on Windows.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Tested-by: Johannes Sixt <j6t@kdbg.org> (MinGW)
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 4411a480c1067f6841181e838ffba54edbec823f..fb5e14d56e5b9fec0a054eb9708be41a59ac0f13 100644 (file)
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -520,6 +520,7 @@ static void write_pack_file(void)
 
                        snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
                                 base_name, sha1_to_hex(sha1));
+                       free_pack_by_name(tmpname);
                        if (adjust_perm(pack_tmp_name, mode))
                                die("unable to make temporary pack file readable: %s",
                                    strerror(errno));

diff --git a/cache.h b/cache.h
index d1cd6aaf738f94930b94ebbee303fc267064e2ac..42f2f2754b93ff9d93883529778190d35a8ea43a 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -738,6 +738,7 @@ extern int open_pack_index(struct packed_git *);
 extern unsigned char* use_pack(struct packed_git *, struct pack_window **, off_t, unsigned int *);
 extern void close_pack_windows(struct packed_git *);
 extern void unuse_pack(struct pack_window **);
+extern void free_pack_by_name(const char *);
 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/sha1_file.c b/sha1_file.c
index c35469d488596bd1279c06bc391d744565f35e59..88035a0cd19d040c8b626684c3ff1f7fdb35e837 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -659,6 +659,37 @@ void unuse_pack(struct pack_window **w_cursor)
        }
 }
 
+/*
+ * This is used by git-repack in case a newly created pack happens to
+ * contain the same set of objects as an existing one.  In that case
+ * the resulting file might be different even if its name would be the
+ * same.  It is best to close any reference to the old pack before it is
+ * replaced on disk.  Of course no index pointers nor windows for given pack
+ * must subsist at this point.  If ever objects from this pack are requested
+ * again, the new version of the pack will be reinitialized through
+ * reprepare_packed_git().
+ */
+void free_pack_by_name(const char *pack_name)
+{
+       struct packed_git *p, **pp = &packed_git;
+
+       while (*pp) {
+               p = *pp;
+               if (strcmp(pack_name, p->pack_name) == 0) {
+                       close_pack_windows(p);
+                       if (p->pack_fd != -1)
+                               close(p->pack_fd);
+                       if (p->index_data)
+                               munmap((void *)p->index_data, p->index_size);
+                       free(p->bad_object_sha1);
+                       *pp = p->next;
+                       free(p);
+                       return;
+               }
+               pp = &p->next;
+       }
+}
+
 /*
  * Do not call this directly as this leaks p->pack_fd on error return;
  * call open_packed_git() instead.