commit: fix a segfault when displaying a commit with unreachable parents

diff --git a/read-cache.c b/read-cache.c
index 6bec833eecae934af1dce18683c70522481b002a..97c38670b45d852b2f07f3d3addb2aaf6dbd8697 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -60,7 +60,7 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st)
        if (fd >= 0) {
                unsigned char sha1[20];
                if (!index_fd(sha1, fd, st, 0, NULL))
-                       match = memcmp(sha1, ce->sha1, 20);
+                       match = hashcmp(sha1, ce->sha1);
                /* index_fd() closed the file descriptor already */
        }
        return match;
@@ -347,11 +347,13 @@ int add_file_to_index(const char *path, int verbose)
        ce->ce_mode = create_ce_mode(st.st_mode);
        if (!trust_executable_bit) {
                /* If there is an existing entry, pick the mode bits
-                * from it.
+                * from it, otherwise force to 644.
                 */
                int pos = cache_name_pos(path, namelen);
                if (pos >= 0)
                        ce->ce_mode = active_cache[pos]->ce_mode;
+               else
+                       ce->ce_mode = create_ce_mode(S_IFREG | 0644);
        }
 
        if (index_path(ce->sha1, path, &st, 1))
@@ -744,7 +746,7 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
        SHA1_Init(&c);
        SHA1_Update(&c, hdr, size - 20);
        SHA1_Final(sha1, &c);
-       if (memcmp(sha1, (char *) hdr + size - 20, 20))
+       if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
                return error("bad index file sha1 signature");
        return 0;
 }
@@ -842,6 +844,23 @@ int read_cache_from(const char *path)
        die("index file corrupt");
 }
 
+int discard_cache()
+{
+       int ret;
+
+       active_nr = active_cache_changed = 0;
+       index_file_timestamp = 0;
+       cache_tree_free(&active_cache_tree);
+       if (cache_mmap == NULL)
+               return 0;
+       ret = munmap(cache_mmap, cache_mmap_size);
+       cache_mmap = NULL;
+       cache_mmap_size = 0;
+
+       /* no need to throw away allocated active_cache */
+       return ret;
+}
+
 #define WRITE_BUFFER_SIZE 8192
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;