qmltc: Do not crash on import namespaces

Pick-to: 6.3
Change-Id: I9767857076ea6ae565c7efd75d64cb47a82b7be7
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

tests/auto/qml/qmltc/CMakeLists.txt

@@ -21,6 +21,7 @@ set(qml_sources
     data/properties.qml
     data/ObjectWithId.qml
     data/documentWithIds.qml
+    data/importNamespace.qml
 
     data/signalHandlers.qml
     data/javaScriptFunctions.qml

tests/auto/qml/qmltc/data/importNamespace.qml

@@ -0,0 +1,4 @@
+import QtQuick as QQ
+QQ.Text {
+    text: "hello, world"
+}

tests/auto/qml/qmltc/tst_qmltc.cpp

@@ -37,6 +37,7 @@
 #include "properties.h"
 #include "objectwithid.h"
 #include "documentwithids.h"
+#include "importnamespace.h"
 
 #include "signalhandlers.h"
 #include "javascriptfunctions.h"
@@ -133,6 +134,7 @@ void tst_qmltc::initTestCase()
         QUrl("qrc:/QmltcTests/data/properties.qml"),
         QUrl("qrc:/QmltcTests/data/ObjectWithId.qml"),
         QUrl("qrc:/QmltcTests/data/documentWithIds.qml"),
+        QUrl("qrc:/QmltcTests/data/importNamespace.qml"),
 
         QUrl("qrc:/QmltcTests/data/signalHandlers.qml"),
         QUrl("qrc:/QmltcTests/data/javaScriptFunctions.qml"),
@@ -529,6 +531,13 @@ void tst_qmltc::ids()
     }
 }
 
+void tst_qmltc::importNamespace()
+{
+    QQmlEngine e;
+    PREPEND_NAMESPACE(importNamespace) created(&e); // compilation of this type shouldn't crash
+    QCOMPARE(created.text(), u"hello, world"_qs);
+}
+
 void tst_qmltc::signalHandlers()
 {
     QQmlEngine e;

tests/auto/qml/qmltc/tst_qmltc.h

@@ -51,6 +51,7 @@ private slots:
     void methods();
     void properties();
     void ids();
+    void importNamespace();
 
     void signalHandlers();
     void jsFunctions();

tools/qmltc/prototype/typeresolver.h

@@ -49,10 +49,18 @@ public:
         QHash<QString, QQmlJSScope::ConstPtr> builtins = m_importer->builtinInternalNames();
         cppNames.reserve(builtins.size() + m_imports.size());
         const auto getInternalName = [](const QQmlJSScope::ConstPtr &t) {
+            if (!t)
+                return QString();
             return t->internalName();
         };
         std::transform(builtins.cbegin(), builtins.cend(), std::back_inserter(cppNames),
                        getInternalName);
+
+        // builtins must be valid: all QQmlJSScopes are not nullptr and have
+        // non-empty internal names. m_imports may have nullptrs, due to import
+        // namespaces
+        Q_ASSERT(std::find(cppNames.cbegin(), cppNames.cend(), QString()) == cppNames.cend());
+
         std::transform(m_imports.cbegin(), m_imports.cend(), std::back_inserter(cppNames),
                        getInternalName);
         return cppNames;