[vala/staging] codegen: Avoid critical when connecting dynamic signals

[Rico Tzschichholz <ricotz src gnome org>]

commit 285bb246b2ea29387b3d01d3a3888a7e3b21b306
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Thu Feb 8 12:08:42 2018 +0100

    codegen: Avoid critical when connecting dynamic signals

 codegen/valagsignalmodule.vala |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/codegen/valagsignalmodule.vala b/codegen/valagsignalmodule.vala
index 15a18cb..ba4b4d1 100644
--- a/codegen/valagsignalmodule.vala
+++ b/codegen/valagsignalmodule.vala
@@ -181,7 +181,9 @@ public class Vala.GSignalModule : GObjectModule {
                        }
                }
 
-               signal_enum.add_value (new CCodeEnumValue ("%s_%s_SIGNAL".printf (get_ccode_upper_case_name 
((TypeSymbol)sig.parent_symbol), get_ccode_upper_case_name (sig))));
+               if (signal_enum != null && sig.parent_symbol is TypeSymbol) {
+                       signal_enum.add_value (new CCodeEnumValue ("%s_%s_SIGNAL".printf 
(get_ccode_upper_case_name ((TypeSymbol) sig.parent_symbol), get_ccode_upper_case_name (sig))));
+               }
 
                sig.accept_children (this);