1 files changed, 57 insertions, 2 deletions

diff --git a/cache-tree.c b/cache-tree.c
index cfe937b0f1..73cb340707 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -320,13 +320,13 @@ static int update_one(struct cache_tree *it,
 		}
 		else {
 			sha1 = ce->sha1;
-			mode = ntohl(ce->ce_mode);
+			mode = ce->ce_mode;
 			entlen = pathlen - baselen;
 		}
 		if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))
 			return error("invalid object %s", sha1_to_hex(sha1));
 
-		if (!ce->ce_mode)
+		if (ce->ce_flags & CE_REMOVE)
 			continue; /* entry being removed */
 
 		strbuf_grow(&buffer, entlen + 100);
@@ -532,3 +532,58 @@ struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 	}
 	return it;
 }
+
+int write_cache_as_tree(unsigned char *sha1, int missing_ok, const char *prefix)
+{
+	int entries, was_valid, newfd;
+
+	/*
+	 * We can't free this memory, it becomes part of a linked list
+	 * parsed atexit()
+	 */
+	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+
+	newfd = hold_locked_index(lock_file, 1);
+
+	entries = read_cache();
+	if (entries < 0)
+		return WRITE_TREE_UNREADABLE_INDEX;
+
+	if (!active_cache_tree)
+		active_cache_tree = cache_tree();
+
+	was_valid = cache_tree_fully_valid(active_cache_tree);
+
+	if (!was_valid) {
+		if (cache_tree_update(active_cache_tree,
+				      active_cache, active_nr,
+				      missing_ok, 0) < 0)
+			return WRITE_TREE_UNMERGED_INDEX;
+		if (0 <= newfd) {
+			if (!write_cache(newfd, active_cache, active_nr) &&
+			    !commit_lock_file(lock_file))
+				newfd = -1;
+		}
+		/* Not being able to write is fine -- we are only interested
+		 * in updating the cache-tree part, and if the next caller
+		 * ends up using the old index with unupdated cache-tree part
+		 * it misses the work we did here, but that is just a
+		 * performance penalty and not a big deal.
+		 */
+	}
+
+	if (prefix) {
+		struct cache_tree *subtree =
+			cache_tree_find(active_cache_tree, prefix);
+		if (!subtree)
+			return WRITE_TREE_PREFIX_ERROR;
+		hashcpy(sha1, subtree->sha1);
+	}
+	else
+		hashcpy(sha1, active_cache_tree->sha1);
+
+	if (0 <= newfd)
+		rollback_lock_file(lock_file);
+
+	return 0;
+}