Fix the QScriptContext::argumentsObject and QScriptContext::argument for js functions

On js functions, if the number of arguments is different from the number
of expected arguments, they are located in different place in the
stackframe.  We need to call the JSC functions that take that into account.

Test is the backtrace test

Reviewed-by: Kent Hansen

1 files changed, 14 insertions, 7 deletions

diff --git a/src/script/api/qscriptcontext.cpp b/src/script/api/qscriptcontext.cpp
index 229c8ab..118b551 100644
--- a/src/script/api/qscriptcontext.cpp
+++ b/src/script/api/qscriptcontext.cpp
@@ -273,9 +273,8 @@ QScriptValue QScriptContext::argument(int index) const
         return QScriptValue();
     if (index >= argumentCount())
         return QScriptValue(QScriptValue::UndefinedValue);
-    JSC::Register* thisRegister = frame->registers() - JSC::RegisterFile::CallFrameHeaderSize - frame->argumentCount();
-    ++index; //skip the 'this' object
-    return QScript::scriptEngineFromExec(frame)->scriptValueFromJSCValue(thisRegister[index].jsValue());
+    QScriptValue v = argumentsObject().property(index);
+    return v;
 }
 
 /*!
@@ -306,15 +305,23 @@ QScriptValue QScriptContext::callee() const
 QScriptValue QScriptContext::argumentsObject() const
 {
     JSC::CallFrame *frame = const_cast<JSC::ExecState*>(QScriptEnginePrivate::frameForContext(this));
-    if (frame == frame->lexicalGlobalObject()->globalExec()) {
-        //global context doesn't have any argument, return an empty object
+
+    if (frame == frame->lexicalGlobalObject()->globalExec() || frame->callerFrame()->hasHostCallFrameFlag()) {
+        // <global> or <eval> context doesn't have arguments.  return an empty object
         return QScriptEnginePrivate::get(QScript::scriptEngineFromExec(frame))->newObject();
     }
-    Q_ASSERT(frame->argumentCount() > 0); //we need at least 'this' otherwise we'll crash later
+
+    //for a js function
+    if (frame->codeBlock() && frame->callee()) {
+        JSC::JSValue result = frame->interpreter()->retrieveArguments(frame, JSC::asFunction(frame->callee()));
+        return QScript::scriptEngineFromExec(frame)->scriptValueFromJSCValue(result);
+    }
+
+    //for a native function
     if (!frame->optionalCalleeArguments()) {
+        Q_ASSERT(frame->argumentCount() > 0); //we need at least 'this' otherwise we'll crash later
         JSC::Arguments* arguments = new (&frame->globalData())JSC::Arguments(frame, JSC::Arguments::NoParameters);
         frame->setCalleeArguments(arguments);
-        frame[JSC::RegisterFile::ArgumentsRegister] = arguments;
     }
     return QScript::scriptEngineFromExec(frame)->scriptValueFromJSCValue(frame->optionalCalleeArguments());
 }