From d52d5df148ceb34ce311ec2983cc90a807c6bc8c Mon Sep 17 00:00:00 2001
From: Ian Gulliver <flamingcow@gmail.com>
Date: Mon, 6 Jul 2015 01:43:56 +0000
Subject: [PATCH] Add a sanity assertion.

---
 clients/c/promise.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clients/c/promise.c b/clients/c/promise.c
index 8c25760..7c386aa 100644
--- a/clients/c/promise.c
+++ b/clients/c/promise.c
@@ -31,6 +31,7 @@ promise *promise_create(promise_callback on_success, promise_callback on_failure
 }
 
 void promise_destroy(promise *promise_obj) {
+  assert(promise_obj->fulfilled);
   assert(!pthread_mutex_destroy(&promise_obj->lock));
   assert(!pthread_cond_destroy(&promise_obj->cond));
   if (promise_obj->result && promise_obj->cleanup) {