[gjs] system: fix return value of gc() and breakpoint()

[Giovanni Campagna <gcampagna src gnome org>]

commit 569712f46a22c21ff3f78ad157c0be9e85f7aed5
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Wed Apr 30 21:51:05 2014 +0200

    system: fix return value of gc() and breakpoint()
    
    These need to return void (undefined), and not themselves (which
    is what happens if SET_RVAL() is not called, due to spidermonkey
    reusing the slot for arguments.callee)

 modules/system.cpp |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/modules/system.cpp b/modules/system.cpp
index b12f766..51f14ef 100644
--- a/modules/system.cpp
+++ b/modules/system.cpp
@@ -91,6 +91,7 @@ gjs_breakpoint(JSContext *context,
     if (!gjs_parse_args(context, "breakpoint", "", argc, argv))
         return JS_FALSE;
     G_BREAKPOINT();
+    JS_SET_RVAL(context, vp, JSVAL_VOID);
     return JS_TRUE;
 }
 
@@ -103,6 +104,7 @@ gjs_gc(JSContext *context,
     if (!gjs_parse_args(context, "gc", "", argc, argv))
         return JS_FALSE;
     JS_GC(JS_GetRuntime(context));
+    JS_SET_RVAL(context, vp, JSVAL_VOID);
     return JS_TRUE;
 }