add recursion guard for GC marking

To achieve behavior of the old back-end. There, the recursion guard
was automatic because a mark flag was set on the object as soon as
marking begun, but in JSC it appears to only be set _after_ the
marking is completed.

3 files changed, 10 insertions, 4 deletions

diff --git a/src/script/bridge/qscriptobject.cpp b/src/script/bridge/qscriptobject.cpp
index a8bd798..a550d39 100644
--- a/src/script/bridge/qscriptobject.cpp
+++ b/src/script/bridge/qscriptobject.cpp
@@ -41,6 +41,7 @@
 
 #include "config.h"
 #include "qscriptobject_p.h"
+#include "private/qobject_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -144,6 +145,11 @@ void QScriptObject::getPropertyNames(JSC::ExecState* exec, JSC::PropertyNameArra
 void QScriptObject::mark()
 {
     Q_ASSERT(!marked());
+    if (!d)
+        d = new Data();
+    if (d->isMarking)
+        return;
+    QBoolBlocker markBlocker(d->isMarking, true);
     if (d && d->data && !d->data.marked())
         d->data.mark();
     if (!d || !d->delegate) {
diff --git a/src/script/bridge/qscriptobject_p.h b/src/script/bridge/qscriptobject_p.h
index a905234..d499c61 100644
--- a/src/script/bridge/qscriptobject_p.h
+++ b/src/script/bridge/qscriptobject_p.h
@@ -69,8 +69,9 @@ public:
     {
         JSC::JSValue data; // QScriptValue::data
         QScriptObjectDelegate *delegate;
+        bool isMarking; // recursion guard
 
-        Data() : delegate(0) {}
+        Data() : delegate(0), isMarking(false) {}
         ~Data();
     };
 
diff --git a/src/script/bridge/qscriptqobject.cpp b/src/script/bridge/qscriptqobject.cpp
index bb701ce..b7a0e44 100644
--- a/src/script/bridge/qscriptqobject.cpp
+++ b/src/script/bridge/qscriptqobject.cpp
@@ -266,9 +266,8 @@ JSC::CallType QtFunction::getCallData(JSC::CallData &callData)
 void QtFunction::mark()
 {
     Q_ASSERT(!marked());
-    if (data->object && !data->object.marked()) {
-        JSC::asObject(data->object)->JSC::JSObject::mark();
-    }
+    if (data->object && !data->object.marked())
+        data->object.mark();
     JSC::InternalFunction::mark();
 }