1 files changed, 47 insertions, 31 deletions
diff --git a/read-cache.c b/read-cache.c
index 383ec6d366..342723e8d6 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -488,11 +488,11 @@ int ie_modified(struct index_state *istate,
 	return 0;
 }
 
-int base_name_compare(const char *name1, int len1, int mode1,
-		      const char *name2, int len2, int mode2)
+int base_name_compare(const char *name1, size_t len1, int mode1,
+		      const char *name2, size_t len2, int mode2)
 {
 	unsigned char c1, c2;
-	int len = len1 < len2 ? len1 : len2;
+	size_t len = len1 < len2 ? len1 : len2;
 	int cmp;
 
 	cmp = memcmp(name1, name2, len);
@@ -517,11 +517,12 @@ int base_name_compare(const char *name1, int len1, int mode1,
  * This is used by routines that want to traverse the git namespace
  * but then handle conflicting entries together when possible.
  */
-int df_name_compare(const char *name1, int len1, int mode1,
-		    const char *name2, int len2, int mode2)
+int df_name_compare(const char *name1, size_t len1, int mode1,
+		    const char *name2, size_t len2, int mode2)
 {
-	int len = len1 < len2 ? len1 : len2, cmp;
 	unsigned char c1, c2;
+	size_t len = len1 < len2 ? len1 : len2;
+	int cmp;
 
 	cmp = memcmp(name1, name2, len);
 	if (cmp)
@@ -1783,6 +1784,8 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 	git_hash_ctx c;
 	unsigned char hash[GIT_MAX_RAWSZ];
 	int hdr_version;
+	unsigned char *start, *end;
+	struct object_id oid;
 
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
 		return error(_("bad signature 0x%08x"), hdr->hdr_signature);
@@ -1793,10 +1796,16 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 	if (!verify_index_checksum)
 		return 0;
 
+	end = (unsigned char *)hdr + size;
+	start = end - the_hash_algo->rawsz;
+	oidread(&oid, start);
+	if (oideq(&oid, null_oid()))
+		return 0;
+
 	the_hash_algo->init_fn(&c);
 	the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
 	the_hash_algo->final_fn(hash, &c);
-	if (!hasheq(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
+	if (!hasheq(hash, start))
 		return error(_("bad index file sha1 signature"));
 	return 0;
 }
@@ -2258,12 +2267,10 @@ static void set_new_index_sparsity(struct index_state *istate)
 	 * If the index's repo exists, mark it sparse according to
 	 * repo settings.
 	 */
-	if (istate->repo) {
-		prepare_repo_settings(istate->repo);
-		if (!istate->repo->settings.command_requires_full_index &&
-		    is_sparse_index_allowed(istate, 0))
-			istate->sparse_index = 1;
-	}
+	prepare_repo_settings(istate->repo);
+	if (!istate->repo->settings.command_requires_full_index &&
+	    is_sparse_index_allowed(istate, 0))
+		istate->sparse_index = 1;
 }
 
 /* remember to discard_cache() before reading a different cache! */
@@ -2288,8 +2295,6 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
 		if (!must_exist && errno == ENOENT) {
-			if (!istate->repo)
-				istate->repo = the_repository;
 			set_new_index_sparsity(istate);
 			return 0;
 		}
@@ -2391,9 +2396,6 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	trace2_data_intmax("index", the_repository, "read/cache_nr",
 			   istate->cache_nr);
 
-	if (!istate->repo)
-		istate->repo = the_repository;
-
 	/*
 	 * If the command explicitly requires a full index, force it
 	 * to be full. Otherwise, correct the sparsity based on repository
@@ -2456,9 +2458,10 @@ int read_index_from(struct index_state *istate, const char *path,
 
 	trace_performance_enter();
 	if (split_index->base)
-		discard_index(split_index->base);
+		release_index(split_index->base);
 	else
-		CALLOC_ARRAY(split_index->base, 1);
+		ALLOC_ARRAY(split_index->base, 1);
+	index_state_init(split_index->base, istate->repo);
 
 	base_oid_hex = oid_to_hex(&split_index->base_oid);
 	base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_oid_hex);
@@ -2497,7 +2500,13 @@ int is_index_unborn(struct index_state *istate)
 	return (!istate->cache_nr && !istate->timestamp.sec);
 }
 
-void discard_index(struct index_state *istate)
+void index_state_init(struct index_state *istate, struct repository *r)
+{
+	struct index_state blank = INDEX_STATE_INIT(r);
+	memcpy(istate, &blank, sizeof(*istate));
+}
+
+void release_index(struct index_state *istate)
 {
 	/*
 	 * Cache entries in istate->cache[] should have been allocated
@@ -2509,20 +2518,17 @@ void discard_index(struct index_state *istate)
 	validate_cache_entries(istate);
 
 	resolve_undo_clear_index(istate);
-	istate->cache_nr = 0;
-	istate->cache_changed = 0;
-	istate->timestamp.sec = 0;
-	istate->timestamp.nsec = 0;
 	free_name_hash(istate);
 	cache_tree_free(&(istate->cache_tree));
-	istate->initialized = 0;
-	istate->fsmonitor_has_run_once = 0;
-	FREE_AND_NULL(istate->fsmonitor_last_update);
-	FREE_AND_NULL(istate->cache);
-	istate->cache_alloc = 0;
+	free(istate->fsmonitor_last_update);
+	free(istate->cache);
 	discard_split_index(istate);
 	free_untracked_cache(istate->untracked);
-	istate->untracked = NULL;
+
+	if (istate->sparse_checkout_patterns) {
+		clear_pattern_list(istate->sparse_checkout_patterns);
+		FREE_AND_NULL(istate->sparse_checkout_patterns);
+	}
 
 	if (istate->ce_mem_pool) {
 		mem_pool_discard(istate->ce_mem_pool, should_validate_cache_entries());
@@ -2530,6 +2536,12 @@ void discard_index(struct index_state *istate)
 	}
 }
 
+void discard_index(struct index_state *istate)
+{
+	release_index(istate);
+	index_state_init(istate, istate->repo);
+}
+
 /*
  * Validate the cache entries of this index.
  * All cache entries associated with this index
@@ -2881,9 +2893,13 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	int ieot_entries = 1;
 	struct index_entry_offset_table *ieot = NULL;
 	int nr, nr_threads;
+	struct repository *r = istate->repo;
 
 	f = hashfd(tempfile->fd, tempfile->filename.buf);
 
+	prepare_repo_settings(r);
+	f->skip_hash = r->settings.index_skip_hash;
+
 	for (i = removed = extended = 0; i < entries; i++) {
 		if (cache[i]->ce_flags & CE_REMOVE)
 			removed++;