make QScriptEngine::setGlobalObject() work to some extent

JSC requires that the global object is actually a
JSGlobalObject instance, whereas QScriptEngine::setGlobalObject()
allows any object to be set as the global object. The way we
solve this is by proxying from an internal global object to the
custom (user-set) object.

We need to take care that the internal global object is never
actually exposed through our API; a brilliantly named helper
function, toUsableValue(), makes that happen.

Evaluating "var a = 10" with a custom global object doesn't work
yet; the variable always ends up in the internal Global Object.
For variable assignments, JSC appears to bypass the normal
JSObject::put() and instead use
JSGlobalObject::copyGlobals{From,To}(), which means I can't
intercept and proxy the assignments.

This commit enough to get the Context2D example working. There's
another bug with iteration of the built-in Global Object's
properties (non-enumerable properties are always skipped by the
JSC C++ API, whereas with QScriptValueIterator they should not
be), but that's a totally separate issue.

1 files changed, 0 insertions, 4 deletions

diff --git a/tests/auto/qscriptengine/tst_qscriptengine.cpp b/tests/auto/qscriptengine/tst_qscriptengine.cpp
index fed5a4c..d657749 100644
--- a/tests/auto/qscriptengine/tst_qscriptengine.cpp
+++ b/tests/auto/qscriptengine/tst_qscriptengine.cpp
@@ -896,11 +896,9 @@ void tst_QScriptEngine::getSetGlobalObject()
     QScriptValue obj = eng.newObject();
     eng.setGlobalObject(obj);
     QVERIFY(eng.globalObject().strictlyEquals(obj));
-    QEXPECT_FAIL("", "this-object for global context", Continue);
     QVERIFY(eng.currentContext()->thisObject().strictlyEquals(obj));
     QEXPECT_FAIL("", "this-object for global context", Continue);
     QVERIFY(eng.currentContext()->activationObject().strictlyEquals(obj));
-    QEXPECT_FAIL("", "", Continue);
     QVERIFY(eng.evaluate("this").strictlyEquals(obj));
     QCOMPARE(eng.globalObject().toString(), QString::fromLatin1("[object Object]"));
 
@@ -909,14 +907,12 @@ void tst_QScriptEngine::getSetGlobalObject()
     obj = eng.newObject();
     eng.setGlobalObject(obj);
     QVERIFY(eng.globalObject().strictlyEquals(obj));
-    QEXPECT_FAIL("", "", Continue);
     QVERIFY(eng.currentContext()->thisObject().strictlyEquals(obj));
     QEXPECT_FAIL("", "", Continue);
     QVERIFY(eng.currentContext()->activationObject().strictlyEquals(obj));
 
     eng.collectGarbage();
     QVERIFY(eng.globalObject().strictlyEquals(obj));
-    QEXPECT_FAIL("", "", Continue);
     QVERIFY(eng.currentContext()->thisObject().strictlyEquals(obj));
     QEXPECT_FAIL("", "", Continue);
     QVERIFY(eng.currentContext()->activationObject().strictlyEquals(obj));