create a default-constructed object when calling native constructors

It's up to the implementation of the constructor to decide whether
it wants to initialize the default-constructed object, or create
and return a new one; just like for JS constructors.
We need this functionality in QtScript so that
QScriptContext::thisObject() will return the right thing.
The built-in constructors (RegExp etc.) should be modified to
initialize the default-constructed object instead of always
creating a new object (only when RegExp is called as a function
should it create a new object).

1 files changed, 11 insertions, 0 deletions

diff --git a/src/3rdparty/webkit/JavaScriptCore/interpreter/Interpreter.cpp b/src/3rdparty/webkit/JavaScriptCore/interpreter/Interpreter.cpp
index f8a3746..d9c5cda 100644
--- a/src/3rdparty/webkit/JavaScriptCore/interpreter/Interpreter.cpp
+++ b/src/3rdparty/webkit/JavaScriptCore/interpreter/Interpreter.cpp
@@ -3495,6 +3495,17 @@ JSValue Interpreter::privateExecute(ExecutionFlag flag, RegisterFile* registerFi
             ArgList args(callFrame->registers() + thisRegister + 1, argCount - 1);
 
             ScopeChainNode* scopeChain = callFrame->scopeChain();
+
+            Structure* structure;
+            JSValue prototype = callFrame[proto].jsValue();
+            if (prototype.isObject())
+                structure = asObject(prototype)->inheritorID();
+            else
+                structure = scopeChain->globalObject()->emptyObjectStructure();
+            JSObject* newObject = new (globalData) JSObject(structure);
+
+            callFrame[thisRegister] = JSValue(newObject); // "this" value
+
             CallFrame* newCallFrame = CallFrame::create(callFrame->registers() + registerOffset);
             newCallFrame->init(0, vPC + 7, scopeChain, callFrame, dst, argCount, asObject(v));