diff --git a/src/hashtable.c b/src/hashtable.c
index e226c8191..c36d8a8e6 100644
--- a/src/hashtable.c
+++ b/src/hashtable.c
@@ -179,11 +179,13 @@ void git_hashtable_free(git_hashtable *self)
 }
 
 
-int git_hashtable_insert(git_hashtable *self, const void *key, void *value)
+int git_hashtable_insert2(git_hashtable *self, const void *key, void *value, void **old_value)
 {
 	int hash_id;
 	git_hashtable_node *node;
 
+	*old_value = NULL;
+
 	for (hash_id = 0; hash_id < GIT_HASHTABLE_HASHES; ++hash_id) {
 		node = node_with_hash(self, key, hash_id);
 
@@ -195,6 +197,8 @@ int git_hashtable_insert(git_hashtable *self, const void *key, void *value)
 		}
 
 		if (key == node->key || self->key_equal(key, node->key) == 0) {
+			*old_value = node->value;
+			node->key = key;
 			node->value = value;
 			return GIT_SUCCESS;
 		}
@@ -241,3 +245,11 @@ int git_hashtable_remove(git_hashtable *self, const void *key)
 	return GIT_ENOTFOUND;
 }
 
+int git_hashtable_merge(git_hashtable *self, git_hashtable *other)
+{
+	if (resize_to(self, (self->size + other->size) * 2) < GIT_SUCCESS)
+		return GIT_ENOMEM;
+
+	return insert_nodes(self, other->nodes, other->key_count);
+}
+
diff --git a/src/hashtable.h b/src/hashtable.h
index 74da580ef..c3475b6ed 100644
--- a/src/hashtable.h
+++ b/src/hashtable.h
@@ -34,11 +34,19 @@ typedef struct git_hashtable git_hashtable;
 git_hashtable *git_hashtable_alloc(size_t min_size, 
 		git_hash_ptr hash,
 		git_hash_keyeq_ptr key_eq);
-int git_hashtable_insert(git_hashtable *h, const void *key, void *value);
 void *git_hashtable_lookup(git_hashtable *h, const void *key);
 int git_hashtable_remove(git_hashtable *table, const void *key);
 void git_hashtable_free(git_hashtable *h);
 void git_hashtable_clear(git_hashtable *h);
+int git_hashtable_merge(git_hashtable *self, git_hashtable *other);
+
+int git_hashtable_insert2(git_hashtable *h, const void *key, void *value, void **old_value);
+
+GIT_INLINE(int) git_hashtable_insert(git_hashtable *h, const void *key, void *value)
+{
+	void *_unused;
+	return git_hashtable_insert2(h, key, value, &_unused);
+}
 
 #define git_hashtable_node_at(nodes, pos) ((git_hashtable_node *)(&nodes[pos]))
 
@@ -57,5 +65,9 @@ void git_hashtable_clear(git_hashtable *h);
 	}\
 }
 
+#define GIT_HASHTABLE_FOREACH_DELETE() {\
+	_node->key = NULL; _node->value = NULL; _self->key_count--;\
+}
+
 
 #endif