[gnome-online-accounts/gnome-3-8] provider: check that provider_type is not NULL in get_for_provider_type()

[Debarshi Ray <debarshir src gnome org>]

commit e14ed7c5165c326808c7726e3aa75c3e35f21a91
Author: Marco Barisione <marco barisione collabora co uk>
Date:   Tue Aug 20 15:47:31 2013 +0100

    provider: check that provider_type is not NULL in get_for_provider_type()
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696267

 src/goabackend/goaprovider.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/goabackend/goaprovider.c b/src/goabackend/goaprovider.c
index 4fa30cf..39636a9 100644
--- a/src/goabackend/goaprovider.c
+++ b/src/goabackend/goaprovider.c
@@ -710,6 +710,8 @@ goa_provider_get_for_provider_type (const gchar *provider_type)
   GIOExtensionPoint *extension_point;
   GoaProvider *ret;
 
+  g_return_val_if_fail (provider_type != NULL, NULL);
+
   ensure_builtins_loaded ();
 
   ret = NULL;