[libpeas] Fix panic when getting global LGI fields

[Garrett Regier <gregier src gnome org>]

commit 0c31653a6db8f21faf7ee7a7bfa28734834e033c
Author: Garrett Regier <garrett regier riftio com>
Date:   Tue Dec 30 09:20:32 2014 -0800

    Fix panic when getting global LGI fields
    
    A panic will occur when using lua_getfield() as LGI
    will attempt to find the value as a typelib. This breaks
    the attempt to report an incorrect LGI version and
    causes a crash.

 loaders/lua5.1/peas-plugin-loader-lua.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/loaders/lua5.1/peas-plugin-loader-lua.c b/loaders/lua5.1/peas-plugin-loader-lua.c
index b98db05..d5464d0 100644
--- a/loaders/lua5.1/peas-plugin-loader-lua.c
+++ b/loaders/lua5.1/peas-plugin-loader-lua.c
@@ -486,15 +486,18 @@ peas_plugin_loader_lua_initialize (PeasPluginLoader *loader)
       return FALSE;
     }
 
-  lua_getfield (L, -1, "lock");
+  lua_pushliteral (L, "lock");
+  lua_rawget (L, -2);
   priv->lgi_lock = lua_touserdata (L, -1);
   lua_pop (L, 1);
 
-  lua_getfield (L, -1, "enter");
+  lua_pushliteral (L, "enter");
+  lua_rawget (L, -2);
   priv->lgi_enter_func = lua_touserdata (L, -1);
   lua_pop (L, 1);
 
-  lua_getfield (L, -1, "leave");
+  lua_pushliteral (L, "leave");
+  lua_rawget (L, -2);
   priv->lgi_leave_func = lua_touserdata (L, -1);
   lua_pop (L, 1);