Pass "this" object when evaluating debug jobs

We have to explicitly specify the "this" object on QV4::Function::call,
otherwise it will assume undefined or the QML global object.

Task-number: QTBUG-66942
Change-Id: I1af7742b4fee1b49e9760a413834daf3edb15d74
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 21 insertions, 8 deletions

diff --git a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
index 5b049ab521..7950d21612 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qv4debugjob.cpp
@@ -112,8 +112,14 @@ void JavaScriptJob::run()
     script.inheritContext = true;
     script.parse();
     QV4::ScopedValue result(scope);
-    if (!scope.engine->hasException)
-        result = script.run();
+    if (!scope.engine->hasException) {
+        if (frame) {
+            QV4::ScopedValue thisObject(scope, frame->thisObject());
+            result = script.run(thisObject);
+        } else {
+            result = script.run();
+        }
+    }
     if (scope.engine->hasException) {
         result = scope.engine->catchException();
         resultIsException = true;
diff --git a/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp b/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
index 718975275a..e17fe92983 100644
--- a/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_nativedebugger/qqmlnativedebugservice.cpp
@@ -260,8 +260,14 @@ QV4::ReturnedValue NativeDebugger::evaluateExpression(const QString &expression)
     // That is a side-effect of inheritContext.
     script.inheritContext = true;
     script.parse();
-    if (!m_engine->hasException)
-        return script.run();
+    if (!m_engine->hasException) {
+        if (m_engine->currentStackFrame) {
+            QV4::ScopedValue thisObject(scope, m_engine->currentStackFrame->thisObject());
+            script.run(thisObject);
+        } else {
+            script.run();
+        }
+    }
 
     m_runningJob = false;
     return QV4::Encode::undefined();
diff --git a/src/qml/jsruntime/qv4script.cpp b/src/qml/jsruntime/qv4script.cpp
index bb6608bec0..267c93952d 100644
--- a/src/qml/jsruntime/qv4script.cpp
+++ b/src/qml/jsruntime/qv4script.cpp
@@ -136,7 +136,7 @@ void Script::parse()
     }
 }
 
-ReturnedValue Script::run()
+ReturnedValue Script::run(const QV4::Value *thisObject)
 {
     if (!parsed)
         parse();
@@ -149,10 +149,11 @@ ReturnedValue Script::run()
     if (qmlContext.isUndefined()) {
         TemporaryAssignment<Function*> savedGlobalCode(engine->globalCode, vmFunction);
 
-        return vmFunction->call(engine->globalObject, nullptr, 0, context);
+        return vmFunction->call(thisObject ? thisObject : engine->globalObject, nullptr, 0,
+                                context);
     } else {
         Scoped<QmlContext> qml(valueScope, qmlContext.value());
-        return vmFunction->call(nullptr, nullptr, 0, qml);
+        return vmFunction->call(thisObject, nullptr, 0, qml);
     }
 }
 
diff --git a/src/qml/jsruntime/qv4script_p.h b/src/qml/jsruntime/qv4script_p.h
index 24291b9aa6..cb03c6b064 100644
--- a/src/qml/jsruntime/qv4script_p.h
+++ b/src/qml/jsruntime/qv4script_p.h
@@ -93,7 +93,7 @@ struct Q_QML_EXPORT Script {
     bool parseAsBinding;
 
     void parse();
-    ReturnedValue run();
+    ReturnedValue run(const QV4::Value *thisObject = nullptr);
 
     Function *function();