Avoid side effects when en exception has been thrown.

We don't want to check for exceptions after every single
line on our runtime methods. A better way to handle this
is to add the check in all methods that have direct side
effects (as e.g. writing to a property of the JS stack).

We also need to return whereever we throw an exception.
To simplify the code, ExecutionContext::throwXxx methods now
return a ReturnedValue (always undefined) for convenience.

Change-Id: Ide6c804f819c731a3f14c6c43121d08029c9fb90
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index ef9dc473f3..12ac4218bd 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -172,7 +172,7 @@ ReturnedValue ErrorObject::method_get_stack(SimpleCallContext *ctx)
     Scope scope(ctx);
     Scoped<ErrorObject> This(scope, ctx->callData->thisObject);
     if (!This)
-        ctx->throwTypeError();
+        return ctx->throwTypeError();
     if (!This->stack) {
         QString trace;
         for (int i = 0; i < This->stackTrace.count(); ++i) {
@@ -389,7 +389,7 @@ ReturnedValue ErrorPrototype::method_toString(SimpleCallContext *ctx)
 
     Object *o = ctx->callData->thisObject.asObject();
     if (!o)
-        ctx->throwTypeError();
+        return ctx->throwTypeError();
 
     ScopedValue name(scope, o->get(ctx->engine->id_name));
     QString qname;