Ensure context is valid before VME method creation

Ensure that a valid context exists prior to evaluation of a VME method
function.  Invalid contexts can occur if a method's first invocation is
triggered after the destruction of the component's context.

Task-number: QTBUG-25516
Change-Id: I349a73c5713e178f920c44f5ddcaa1dc6eec199f
Reviewed-by: Chris Adams <christopher.adams@nokia.com>

3 files changed, 29 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlcontext/data/ContainerComponent.qml b/tests/auto/qml/qqmlcontext/data/ContainerComponent.qml
new file mode 100644
index 0000000000..ae90c20cf8
--- /dev/null
+++ b/tests/auto/qml/qqmlcontext/data/ContainerComponent.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.0
+
+Item {
+    function doSomething() { if (333 == 666) console.log('doSomething') }
+}
diff --git a/tests/auto/qml/qqmlcontext/data/ContentComponent.qml b/tests/auto/qml/qqmlcontext/data/ContentComponent.qml
new file mode 100644
index 0000000000..f937b196ed
--- /dev/null
+++ b/tests/auto/qml/qqmlcontext/data/ContentComponent.qml
@@ -0,0 +1,10 @@
+import QtQuick 2.0
+
+Item {
+    property int count: 0
+    property bool hasValidParent: parent && parent.children.length != 0
+
+    onHasValidParentChanged: {
+        if (++count > 1) parent.doSomething()
+    }
+}
diff --git a/tests/auto/qml/qqmlcontext/data/evalAfterInvalidate.qml b/tests/auto/qml/qqmlcontext/data/evalAfterInvalidate.qml
new file mode 100644
index 0000000000..27879c48bf
--- /dev/null
+++ b/tests/auto/qml/qqmlcontext/data/evalAfterInvalidate.qml
@@ -0,0 +1,14 @@
+import QtQuick 2.0
+
+Rectangle {
+    id: root
+
+    Component.onCompleted: {
+        var i = containerComponent.createObject(root);
+        contentComponent.createObject(i);
+        i.destroy()
+    }
+
+    property Component containerComponent: ContainerComponent {}
+    property Component contentComponent: ContentComponent {}
+}