[gnome-games] retro: Check existence of module file

[Adrien Plazas <aplazas src gnome org>]

commit 431a74ef52c54682c472a0d8a72630825f9904ac
Author: theawless <theawless gmail com>
Date:   Tue Mar 14 20:43:33 2017 +0530

    retro: Check existence of module file
    
    Retro.CoreDescriptor.get_module_file() returns null when module file is
    not found. Null check module file before getting its path for Retro.Core.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779924

 src/retro/retro-core-source.vala |    2 ++
 src/retro/retro-runner.vala      |    3 +++
 2 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/retro/retro-core-source.vala b/src/retro/retro-core-source.vala
index 1828c00..946207d 100644
--- a/src/retro/retro-core-source.vala
+++ b/src/retro/retro-core-source.vala
@@ -21,6 +21,8 @@ public class Games.RetroCoreSource : Object {
                ensure_module_is_found ();
 
                var module_file = core_descriptor.get_module_file ();
+               if (module_file == null)
+                       throw new RetroError.MODULE_NOT_FOUND (_("No module found for platform “%s” and MIME 
types [ “%s” ]."), platform, string.joinv (_("”, “"), mime_types));
 
                return module_file.get_path ();
        }
diff --git a/src/retro/retro-runner.vala b/src/retro/retro-runner.vala
index 9d31c34..b749de2 100644
--- a/src/retro/retro-runner.vala
+++ b/src/retro/retro-runner.vala
@@ -259,6 +259,9 @@ public class Games.RetroRunner : Object, Runner {
                string module_path;
                if (core_descriptor != null) {
                        var module_file = core_descriptor.get_module_file ();
+                       if (module_file == null)
+                               throw new RetroError.MODULE_NOT_FOUND (_("No module found for “%s”."), 
core_descriptor.get_name ());
+
                        module_path = module_file.get_path ();
                }
                else