4 files changed, 62 insertions, 15 deletions

diff --git a/src/script/api/qscriptengine.cpp b/src/script/api/qscriptengine.cpp
index 63041db..02293ea 100644
--- a/src/script/api/qscriptengine.cpp
+++ b/src/script/api/qscriptengine.cpp
@@ -828,12 +828,14 @@ QScriptEnginePrivate::QScriptEnginePrivate() : idGenerator(1)
     currentFrame = exec;
 
     originalGlobalObjectProxy = 0;
-    agent = 0;
+    activeAgent = 0;
     processEventsInterval = -1;
 }
 
 QScriptEnginePrivate::~QScriptEnginePrivate()
 {
+    while (!ownedAgents.isEmpty())
+        delete ownedAgents.takeFirst();
     detachAllRegisteredScriptValues();
     qDeleteAll(m_qobjectData);
     qDeleteAll(m_typeInfos);
@@ -1189,6 +1191,15 @@ QScript::TimeoutCheckerProxy *QScriptEnginePrivate::timeoutChecker() const
     return static_cast<QScript::TimeoutCheckerProxy*>(globalData->timeoutChecker);
 }
 
+void QScriptEnginePrivate::agentDeleted(QScriptEngineAgent *agent)
+{
+    ownedAgents.removeOne(agent);
+    if (activeAgent == agent) {
+        QScriptEngineAgentPrivate::get(agent)->detach();
+        activeAgent = 0;
+    }
+}
+
 #ifndef QT_NO_QOBJECT
 
 JSC::JSValue QScriptEnginePrivate::newQObject(
@@ -3603,11 +3614,20 @@ QT_END_INCLUDE_NAMESPACE
 void QScriptEngine::setAgent(QScriptEngineAgent *agent)
 {
     Q_D(QScriptEngine);
-    if (d->agent)
-        QScriptEngineAgentPrivate::get(d->agent)->detach();
-    d->agent = agent;
-    if (agent)
-        QScriptEngineAgentPrivate::get(d->agent)->attach();
+    if (agent && (agent->engine() != this)) {
+        qWarning("QScriptEngine::setAgent(): "
+                 "cannot set agent belonging to different engine");
+        return;
+    }
+    if (d->activeAgent)
+        QScriptEngineAgentPrivate::get(d->activeAgent)->detach();
+    d->activeAgent = agent;
+    if (agent) {
+        int index = d->ownedAgents.indexOf(agent);
+        if (index == -1)
+            d->ownedAgents.append(agent);
+        QScriptEngineAgentPrivate::get(agent)->attach();
+    }
 }
 
 /*!
@@ -3621,7 +3641,7 @@ void QScriptEngine::setAgent(QScriptEngineAgent *agent)
 QScriptEngineAgent *QScriptEngine::agent() const
 {
     Q_D(const QScriptEngine);
-    return d->agent;
+    return d->activeAgent;
 }
 
 /*!
diff --git a/src/script/api/qscriptengine_p.h b/src/script/api/qscriptengine_p.h
index 53972a2..3a5c79d 100644
--- a/src/script/api/qscriptengine_p.h
+++ b/src/script/api/qscriptengine_p.h
@@ -174,6 +174,8 @@ public:
 
     QScript::TimeoutCheckerProxy *timeoutChecker() const;
 
+    void agentDeleted(QScriptEngineAgent *agent);
+
 #ifndef QT_NO_QOBJECT
     JSC::JSValue newQObject(QObject *object,
         QScriptEngine::ValueOwnership ownership = QScriptEngine::QtOwnership,
@@ -235,7 +237,8 @@ public:
     QScript::QVariantPrototype *variantPrototype;
     WTF::RefPtr<JSC::Structure> variantWrapperObjectStructure;
 
-    QScriptEngineAgent *agent;
+    QList<QScriptEngineAgent*> ownedAgents;
+    QScriptEngineAgent *activeAgent;
     QHash<JSC::JSCell*, QBasicAtomicInt> keepAliveValues;
     QHash<int, QScriptTypeInfo*> m_typeInfos;
     int processEventsInterval;
diff --git a/src/script/api/qscriptengineagent.cpp b/src/script/api/qscriptengineagent.cpp
index 9c352ad..4f89e81 100644
--- a/src/script/api/qscriptengineagent.cpp
+++ b/src/script/api/qscriptengineagent.cpp
@@ -205,6 +205,8 @@ QScriptEngineAgent::QScriptEngineAgent(QScriptEngineAgentPrivate &dd, QScriptEng
 */
 QScriptEngineAgent::~QScriptEngineAgent()
 {
+    QScriptEnginePrivate *eng_p = QScriptEnginePrivate::get(engine());
+    eng_p->agentDeleted(this);
     delete d_ptr;
     d_ptr = 0;
 }
diff --git a/tests/auto/qscriptengine/tst_qscriptengine.cpp b/tests/auto/qscriptengine/tst_qscriptengine.cpp
index eb24616..cf6ebd8 100644
--- a/tests/auto/qscriptengine/tst_qscriptengine.cpp
+++ b/tests/auto/qscriptengine/tst_qscriptengine.cpp
@@ -3649,13 +3649,35 @@ public:
 
 void tst_QScriptEngine::getSetAgent()
 {
-    QScriptEngine eng;
-    QCOMPARE(eng.agent(), (QScriptEngineAgent*)0);
-    TestAgent agent(&eng);
-    eng.setAgent(&agent);
-    QCOMPARE(eng.agent(), (QScriptEngineAgent*)&agent);
-    eng.setAgent(0);
-    QCOMPARE(eng.agent(), (QScriptEngineAgent*)0);
+    // case 1: engine deleted before agent --> agent deleted too
+    {
+        QScriptEngine *eng = new QScriptEngine;
+        QCOMPARE(eng->agent(), (QScriptEngineAgent*)0);
+        TestAgent *agent = new TestAgent(eng);
+        eng->setAgent(agent);
+        QCOMPARE(eng->agent(), (QScriptEngineAgent*)agent);
+        eng->setAgent(0); // the engine maintains ownership of the old agent
+        QCOMPARE(eng->agent(), (QScriptEngineAgent*)0);
+        delete eng;
+    }
+    // case 2: agent deleted before engine --> engine's agent should become 0
+    {
+        QScriptEngine *eng = new QScriptEngine;
+        TestAgent *agent = new TestAgent(eng);
+        eng->setAgent(agent);
+        QCOMPARE(eng->agent(), (QScriptEngineAgent*)agent);
+        delete agent;
+        QCOMPARE(eng->agent(), (QScriptEngineAgent*)0);
+        eng->evaluate("(function(){ return 123; })()");
+        delete eng;
+    }
+    {
+        QScriptEngine eng;
+        QScriptEngine eng2;
+        TestAgent *agent = new TestAgent(&eng);
+        QTest::ignoreMessage(QtWarningMsg, "QScriptEngine::setAgent(): cannot set agent belonging to different engine");
+        eng2.setAgent(agent);
+    }
 }
 
 void tst_QScriptEngine::reentrancy()