Do not search for Singletons from more recent versions

This would break importing older versions of a module, as we would try
to locate a singleton which does not exist in this version.

Fixes: QTBUG-77102
Change-Id: I78be1ec111d2be26a14b2a94bbf743cf6238cddd
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

10 files changed, 143 insertions, 1 deletions

diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index 5a1364473e..ba8dce4b6e 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -465,9 +465,18 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
 
         const QQmlDirComponents &components = import->qmlDirComponents;
 
+        const int importMajorVersion = import->majversion;
+        const int importMinorVersion = import->minversion;
+        auto shouldSkipSingleton = [importMajorVersion, importMinorVersion](int singletonMajorVersion, int singletonMinorVersion) -> bool {
+            return importMajorVersion != -1 &&
+                    (singletonMajorVersion > importMajorVersion || (singletonMajorVersion == importMajorVersion && singletonMinorVersion > importMinorVersion));
+        };
+
         ConstIterator cend = components.constEnd();
         for (ConstIterator cit = components.constBegin(); cit != cend; ++cit) {
             if (cit->singleton && excludeBaseUrl(import->url, cit->fileName, baseUrl.toString())) {
+                if (shouldSkipSingleton(cit->majorVersion, cit->minorVersion))
+                    continue;
                 QQmlImports::CompositeSingletonReference ref;
                 ref.typeName = cit->typeName;
                 ref.prefix = set.prefix;
@@ -478,7 +487,9 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
         }
 
         if (QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion)) {
-            module->walkCompositeSingletons([&resultList, &set](const QQmlType &singleton) {
+            module->walkCompositeSingletons([&resultList, &set, &shouldSkipSingleton](const QQmlType &singleton) {
+                if (shouldSkipSingleton(singleton.majorVersion(), singleton.minorVersion()))
+                    return;
                 QQmlImports::CompositeSingletonReference ref;
                 ref.typeName = singleton.elementName();
                 ref.prefix = set.prefix;
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_0_9.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_0_9.qml
new file mode 100644
index 0000000000..a63e2d121c
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_0_9.qml
@@ -0,0 +1,14 @@
+import QtQuick 2.0
+
+Rectangle {
+    width: 50
+    height: 50
+
+    color: "yellow"
+
+    Text {
+        anchors.centerIn: parent
+        text: "0.9"
+
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_1_0.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_1_0.qml
new file mode 100644
index 0000000000..d9cff582bb
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MyComponent_1_0.qml
@@ -0,0 +1,15 @@
+
+import QtQuick 2.0
+
+Rectangle {
+    width: 50
+    height: 50
+
+    color: "orange"
+
+    Text {
+        anchors.centerIn: parent
+        text: "1.0"
+
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MySettings_1_0.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MySettings_1_0.qml
new file mode 100644
index 0000000000..63ad6ba1a5
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/MySettings_1_0.qml
@@ -0,0 +1,7 @@
+pragma Singleton
+
+import QtQuick 2.0
+
+Item {
+    property int baseWidth: 50
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/qmldir b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/qmldir
new file mode 100644
index 0000000000..57b8c55f81
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/imports/MyPlugin/qmldir
@@ -0,0 +1,6 @@
+module MyPlugin
+
+MyComponent 0.9 MyComponent_0_9.qml
+
+MyComponent 1.0 MyComponent_1_0.qml
+singleton MySettings 1.0 MySettings_1_0.qml
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.fail.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.fail.qml
new file mode 100644
index 0000000000..0fbcec607a
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.fail.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.12
+import MyPlugin 0.9
+
+Item {
+    width: MySettings.baseWidth
+    height: 100
+
+    MyComponent {
+        anchors.centerIn: parent
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.qml
new file mode 100644
index 0000000000..53fc25699c
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.0.9.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.12
+import MyPlugin 0.9
+
+Item {
+    width: 100
+    height: 100
+
+    MyComponent {
+        anchors.centerIn: parent
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.1.0.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.1.0.qml
new file mode 100644
index 0000000000..1f6244068b
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.1.0.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.12
+import MyPlugin 1.0
+
+Item {
+    width: MySettings.baseWidth
+    height: 100
+
+    MyComponent {
+        anchors.centerIn: parent
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.nonumber.qml b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.nonumber.qml
new file mode 100644
index 0000000000..dea00c0163
--- /dev/null
+++ b/tests/auto/qml/qqmlimport/data/QTBUG-77102/main.nonumber.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.12
+import "imports/MyPlugin"
+
+Item {
+    width: MySettings.baseWidth
+    height: 100
+
+    MyComponent {
+        anchors.centerIn: parent
+    }
+}
diff --git a/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp b/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
index a3cb68fdcb..a9657eba1d 100644
--- a/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
+++ b/tests/auto/qml/qqmlimport/tst_qqmlimport.cpp
@@ -45,6 +45,7 @@ private slots:
     void completeQmldirPaths_data();
     void completeQmldirPaths();
     void interceptQmldir();
+    void singletonVersionResolution();
     void cleanup();
 };
 
@@ -212,6 +213,50 @@ void tst_QQmlImport::interceptQmldir()
     QVERIFY(!obj.isNull());
 }
 
+// QTBUG-77102
+void tst_QQmlImport::singletonVersionResolution()
+{
+    QQmlEngine engine;
+    engine.addImportPath(testFile("QTBUG-77102/imports"));
+    {
+        // Singleton with higher version is simply ignored when importing lower version of plugin
+        QQmlComponent component(&engine);
+        component.loadUrl(testFileUrl("QTBUG-77102/main.0.9.qml"));
+        QVERIFY(component.isReady());
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+    }
+    {
+        // but the singleton is not accessible
+        QQmlComponent component(&engine);
+        QTest::ignoreMessage(QtMsgType::QtWarningMsg, QRegularExpression {".*ReferenceError: MySettings is not defined$"} );
+        component.loadUrl(testFileUrl("QTBUG-77102/main.0.9.fail.qml"));
+        QVERIFY(component.isReady());
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+    }
+    {
+        // unless a version which is high enough is imported
+        QQmlComponent component(&engine);
+        component.loadUrl(testFileUrl("QTBUG-77102/main.1.0.qml"));
+        QVERIFY(component.isReady());
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        auto item = qobject_cast<QQuickItem*>(obj.get());
+        QCOMPARE(item->width(), 50);
+    }
+    {
+        // or when there is no number because we are importing from a path
+        QQmlComponent component(&engine);
+        component.loadUrl(testFileUrl("QTBUG-77102/main.nonumber.qml"));
+        QVERIFY(component.isReady());
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        auto item = qobject_cast<QQuickItem*>(obj.get());
+        QCOMPARE(item->width(), 50);
+    }
+}
+
 
 QTEST_MAIN(tst_QQmlImport)