Fix dynamic properties in QQmlPropertyMap not always being visible in QML

QQmlPropertyMap is a fully dynamic class that can add properties at any point
in time. In order for these properties to be visible inside QML, we must
disable the property cache (instead of trying to unsuccessfully re-fresh it).

What happened in this particular case is that the QQmlPropertyMap derived type
was instantiated and the VME instruction for creating it would also assign the
property cache the compiler determined. There's no way for QQmlPropertyMap
itself to access this property cache instance (stored in
output->types[id].typePropertyCache) or invalidate it, so instead don't use the
compiler's property cache when instantiating the type.

This patch also disallows the adding properties to QQmlPropertyMap when it
is used as base type for a new QML type, as we cannot provide the derived
type to the QQmlPropertyMap constructor - this is only possible in C++.

Task-number: QTBUG-35233
Change-Id: I7fa9e4a2224ccfdd7ccb3fd9f73919ecd46058a8
Reviewed-by: Alberto Mardegan <mardy@users.sourceforge.net>
Reviewed-by: Alan Alpert (Personal) <416365416c@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlcompiler.cpp b/src/qml/qml/qqmlcompiler.cpp
index 675f242f39..2b925b24ec 100644
--- a/src/qml/qml/qqmlcompiler.cpp
+++ b/src/qml/qml/qqmlcompiler.cpp
@@ -848,6 +848,8 @@ bool QQmlCompiler::compile(QQmlEngine *engine,
             }
         }
 
+        ref.doDynamicTypeCheck();
+
         out->types << ref;
     }
 
@@ -859,6 +861,19 @@ bool QQmlCompiler::compile(QQmlEngine *engine,
         if (componentStats)
             dumpStats();
         Q_ASSERT(out->rootPropertyCache);
+
+        // Any QQmlPropertyMap instances for example need to have their property cache removed,
+        // because the class is too dynamic and allows adding properties at any point at run-time.
+        for (int i = 0; i < output->types.count(); ++i) {
+            QQmlCompiledData::TypeReference &tr = output->types[i];
+            if (!tr.typePropertyCache)
+                continue;
+
+            if (tr.isFullyDynamicType) {
+                tr.typePropertyCache->release();
+                tr.typePropertyCache = 0;
+            }
+        }
     } else {
         reset(out);
     }
@@ -1227,6 +1242,7 @@ void QQmlCompiler::genObject(QQmlScript::Object *obj, bool parentToSuper)
 
     // Setup the synthesized meta object if necessary
     if (!obj->synthdata.isEmpty()) {
+        Q_ASSERT(!output->types.at(obj->type).isFullyDynamicType);
         Instruction::StoreMetaObject meta;
         meta.aliasData = output->indexForByteArray(obj->synthdata);
         meta.propertyCache = output->propertyCaches.count();
@@ -2705,6 +2721,15 @@ int QQmlCompiler::bindingIdentifier(const QString &name, const Variant &value, c
 // Ensures that the dynamic meta specification on obj is valid
 bool QQmlCompiler::checkDynamicMeta(QQmlScript::Object *obj)
 {
+    if (output->types[obj->type].isFullyDynamicType) {
+        if (!obj->dynamicProperties.isEmpty())
+            COMPILE_EXCEPTION(obj, tr("Fully dynamic types cannot declare new properties."));
+        if (!obj->dynamicSignals.isEmpty())
+            COMPILE_EXCEPTION(obj, tr("Fully dynamic types cannot declare new signals."));
+        if (!obj->dynamicSlots.isEmpty())
+            COMPILE_EXCEPTION(obj, tr("Fully Dynamic types cannot declare new functions."));
+    }
+
     bool seenDefaultProperty = false;
 
     // We use a coarse grain, 31 bit hash to check if there are duplicates.