[librest/wip/baedert/gtask2: 3/8] rest-proxy: Fix precondition in new_call

[Timm Bäder <baedert src gnome org>]

commit 430da5974d2479f128d28c4caf7177a1da6c9e88
Author: Timm Bäder <mail baedert org>
Date:   Thu Jul 14 12:34:20 2016 +0200

    rest-proxy: Fix precondition in new_call

 rest/rest-proxy.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/rest/rest-proxy.c b/rest/rest-proxy.c
index 086c217..ca42aac 100644
--- a/rest/rest-proxy.c
+++ b/rest/rest-proxy.c
@@ -598,7 +598,11 @@ _rest_proxy_new_call (RestProxy *proxy)
 RestProxyCall *
 rest_proxy_new_call (RestProxy *proxy)
 {
-  RestProxyClass *proxy_class = REST_PROXY_GET_CLASS (proxy);
+  RestProxyClass *proxy_class;
+
+  g_return_val_if_fail (REST_IS_PROXY (proxy), NULL);
+
+  proxy_class = REST_PROXY_GET_CLASS (proxy);
   return proxy_class->new_call (proxy);
 }