From e72d3772d57573dd9865370c925345045ecdce69 Mon Sep 17 00:00:00 2001
From: Ulf Hermann <ulf.hermann@qt.io>
Date: Tue, 30 Nov 2021 14:39:48 +0100
Subject: [PATCH 14/31] Qml: Don't crash when as-casting to type with errors

Such types don't have a compilation unit, but we still know their names.

Pick-to: 6.2
Fixes: QTBUG-98792
Change-Id: I2db8dea3a5a02ec1492f7f7a054fd3ad4c6ad69a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
(cherry picked from commit e0cd201e91ae64b9c03e0128cd17656b00611fbb)
---
 src/qml/qml/qqmltypewrapper.cpp                  |  6 ++++--
 src/qml/types/qqmlconnections.cpp                |  2 +-
 tests/auto/qml/qqmllanguage/data/Broken.qml      |  5 +++++
 tests/auto/qml/qqmllanguage/data/asBroken.qml    |  6 ++++++
 tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp | 16 ++++++++++++++++
 5 files changed, 32 insertions(+), 3 deletions(-)
 create mode 100644 tests/auto/qml/qqmllanguage/data/Broken.qml
 create mode 100644 tests/auto/qml/qqmllanguage/data/asBroken.qml

diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index 175de8b936..a6ba4b8cb3 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -419,8 +419,10 @@ ReturnedValue QQmlTypeWrapper::virtualInstanceOf(const Object *typeObject, const
             return Encode(false);
 
         QQmlRefPointer<QQmlTypeData> td = qenginepriv->typeLoader.getType(typeWrapper->d()->type().sourceUrl());
-        ExecutableCompilationUnit *cu = td->compilationUnit();
-        myQmlType = qenginepriv->metaObjectForType(cu->metaTypeId);
+        if (ExecutableCompilationUnit *cu = td->compilationUnit())
+            myQmlType = qenginepriv->metaObjectForType(cu->metaTypeId);
+        else
+            return Encode(false); // It seems myQmlType has some errors, so we could not compile it.
     } else {
         myQmlType = qenginepriv->metaObjectForType(myTypeId);
     }
diff --git a/src/qml/types/qqmlconnections.cpp b/src/qml/types/qqmlconnections.cpp
index 4a4e6ce12c..a5889b7396 100644
--- a/src/qml/types/qqmlconnections.cpp
+++ b/src/qml/types/qqmlconnections.cpp
@@ -341,7 +341,7 @@ void QQmlConnections::connectSignalsToMethods()
                    && propName.at(2).isUpper()) {
             qmlWarning(this) << tr("Detected function \"%1\" in Connections element. "
                                    "This is probably intended to be a signal handler but no "
-                                   "signal of the target matches the name.").arg(propName);
+                                   "signal of the \"%2\" target matches the name.").arg(propName).arg(target->metaObject()->className());
         }
     }
 }
diff --git a/tests/auto/qml/qqmllanguage/data/Broken.qml b/tests/auto/qml/qqmllanguage/data/Broken.qml
new file mode 100644
index 0000000000..e24d9112a8
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/Broken.qml
@@ -0,0 +1,5 @@
+import QtQml 2.15
+
+QtObject {
+    notThere: 5
+}
diff --git a/tests/auto/qml/qqmllanguage/data/asBroken.qml b/tests/auto/qml/qqmllanguage/data/asBroken.qml
new file mode 100644
index 0000000000..bd88d14c76
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/asBroken.qml
@@ -0,0 +1,6 @@
+import QtQml 2.15
+
+QtObject {
+    id: self
+    property var selfAsBroken: self as Broken
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index ac6634290a..d16d117d65 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -337,6 +337,7 @@ private slots:
     void bareInlineComponent();
 
     void hangOnWarning();
+    void objectAsBroken();
 
     void ambiguousContainingType();
     void staticConstexprMembers();
@@ -5951,6 +5952,21 @@ void tst_qqmllanguage::badGroupedProperty()
              .arg(url.toString()));
 }
 
+void tst_qqmllanguage::objectAsBroken()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("asBroken.qml"));
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> o(c.create());
+    QVERIFY(!o.isNull());
+    QVariant selfAsBroken = o->property("selfAsBroken");
+    QVERIFY(selfAsBroken.isValid());
+    // QCOMPARE(selfAsBroken.metaType(), QMetaType::fromType<std::nullptr_t>());
+
+    QQmlComponent b(&engine, testFileUrl("Broken.qml"));
+    QVERIFY(b.isError());
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"
-- 
2.43.0