8 files changed, 97 insertions, 8 deletions
diff --git a/src/qmlcompiler/qqmljsutils.cpp b/src/qmlcompiler/qqmljsutils.cpp
index 229e8f29ad..0ced8254b5 100644
--- a/src/qmlcompiler/qqmljsutils.cpp
+++ b/src/qmlcompiler/qqmljsutils.cpp
@@ -25,17 +25,23 @@ resolveAlias(ScopeForId scopeForId, const QQmlJSMetaProperty &property,
     QQmlJSUtils::ResolvedAlias result {};
     result.owner = owner;
 
-    for (QQmlJSMetaProperty nextProperty = property; nextProperty.isAlias();) {
-
-        // this is a special (seemingly useless) section which is necessary when
-        // we have an alias pointing to an alias. this way we avoid a check
-        // whether a property is an alias at the very end of the loop body
+    // TODO: one could optimize the generated alias code for aliases pointing to aliases
+    //  e.g., if idA.myAlias -> idB.myAlias2 -> idC.myProp, then one could directly generate
+    //  idA.myProp as pointing to idC.myProp.
+    //  This gets complicated when idB.myAlias is in a different Component than where the
+    //  idA.myAlias is defined: scopeForId currently only contains the ids of the current
+    //  component and alias resolution on the ids of a different component fails then.
+    if (QQmlJSMetaProperty nextProperty = property; nextProperty.isAlias()) {
         QQmlJSScope::ConstPtr resultOwner = result.owner;
         result = QQmlJSUtils::ResolvedAlias {};
 
         visitor.reset();
 
         auto aliasExprBits = nextProperty.aliasExpression().split(u'.');
+        // do not crash on invalid aliasexprbits when accessing aliasExprBits[0]
+        if (aliasExprBits.size() < 1)
+            return {};
+
         // resolve id first:
         resultOwner = scopeForId(aliasExprBits[0], resultOwner);
         if (!resultOwner)
@@ -46,8 +52,6 @@ resolveAlias(ScopeForId scopeForId, const QQmlJSMetaProperty &property,
         aliasExprBits.removeFirst(); // Note: for simplicity, remove the <id>
         result.owner = resultOwner;
         result.kind = QQmlJSUtils::AliasTarget_Object;
-        // reset the property to avoid endless loop when aliasExprBits is empty
-        nextProperty = QQmlJSMetaProperty {};
 
         for (const QString &bit : std::as_const(aliasExprBits)) {
             nextProperty = resultOwner->property(bit);
diff --git a/tests/auto/qml/qmltc/QmltcTests/CMakeLists.txt b/tests/auto/qml/qmltc/QmltcTests/CMakeLists.txt
index 7712dcf992..36e4d1413b 100644
--- a/tests/auto/qml/qmltc/QmltcTests/CMakeLists.txt
+++ b/tests/auto/qml/qmltc/QmltcTests/CMakeLists.txt
@@ -101,6 +101,7 @@ set(qml_sources
     appendToQQmlListProperty.qml
     inlineComponents.qml
     repeaterCrash.qml
+    aliases.qml
 
     # support types:
     DefaultPropertySingleChild.qml
@@ -110,6 +111,9 @@ set(qml_sources
     LocalWithOnCompleted.qml
     LocallyImported_context.qml
 #   SingletonThing.qml
+    ComponentWithAlias1.qml
+    ComponentWithAlias2.qml
+    ComponentWithAlias3.qml
 
     badFile.qml
 )
diff --git a/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias1.qml b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias1.qml
new file mode 100644
index 0000000000..210cf1e159
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias1.qml
@@ -0,0 +1,8 @@
+import QtQuick
+
+Item {
+    property alias setMe: firstComponent.setMe
+    ComponentWithAlias2 {
+        id: firstComponent
+    }
+}
diff --git a/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias2.qml b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias2.qml
new file mode 100644
index 0000000000..818f3a464e
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias2.qml
@@ -0,0 +1,8 @@
+import QtQuick
+
+Item {
+    property alias setMe: firstComponent.setMe
+    ComponentWithAlias3 {
+        id: firstComponent
+    }
+}
diff --git a/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias3.qml b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias3.qml
new file mode 100644
index 0000000000..87b917ad19
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcTests/ComponentWithAlias3.qml
@@ -0,0 +1,5 @@
+import QtQuick
+
+Item {
+    property string setMe: "Set me!"
+}
diff --git a/tests/auto/qml/qmltc/QmltcTests/aliases.qml b/tests/auto/qml/qmltc/QmltcTests/aliases.qml
new file mode 100644
index 0000000000..9f13f7b17a
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcTests/aliases.qml
@@ -0,0 +1,29 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+import QtQuick
+
+Item {
+    property alias aliasToAlias: subItem.aliasToAlias
+    Item {
+        id: subItem
+        property alias aliasToAlias: subsubItem.aliasToAlias
+
+        Item {
+            id: subsubItem
+            property alias aliasToAlias: subsubsubItem.value
+
+                Item {
+                id: subsubsubItem
+                property string value: "Hello World!"
+            }
+        }
+    }
+
+    property alias aliasToOtherFile: inOtherFile.setMe
+
+    ComponentWithAlias1 {
+        id: inOtherFile
+    }
+}
+
diff --git a/tests/auto/qml/qmltc/tst_qmltc.cpp b/tests/auto/qml/qmltc/tst_qmltc.cpp
index 26265fcb46..2c5a164989 100644
--- a/tests/auto/qml/qmltc/tst_qmltc.cpp
+++ b/tests/auto/qml/qmltc/tst_qmltc.cpp
@@ -76,7 +76,7 @@
 #include "appendtoqqmllistproperty.h"
 #include "inlinecomponents.h"
 #include "repeatercrash.h"
-
+#include "aliases.h"
 #include "testprivateproperty.h"
 
 // Qt:
@@ -2930,4 +2930,34 @@ void tst_qmltc::inlineComponents()
     }
 }
 
+void tst_qmltc::aliases()
+{
+    QQmlEngine e;
+    PREPEND_NAMESPACE(aliases) fromQmltc(&e);
+
+    QQmlComponent component(&e);
+    component.loadUrl(QUrl("qrc:/qt/qml/QmltcTests/aliases.qml"));
+    QVERIFY(!component.isError());
+    QScopedPointer<QObject> fromComponent(component.create());
+    const QString testString = u"myTestString"_s;
+
+    QCOMPARE(fromQmltc.aliasToAlias(), u"Hello World!"_s);
+    QCOMPARE(fromComponent->property("aliasToAlias"), u"Hello World!"_s);
+
+    fromQmltc.setAliasToAlias(testString);
+    QVERIFY(fromComponent->setProperty("aliasToAlias", testString));
+
+    QCOMPARE(fromQmltc.aliasToAlias(), testString);
+    QCOMPARE(fromComponent->property("aliasToAlias"), testString);
+
+    QCOMPARE(fromQmltc.aliasToOtherFile(), u"Set me!"_s);
+    QCOMPARE(fromComponent->property("aliasToOtherFile"), u"Set me!"_s);
+
+    fromQmltc.setAliasToOtherFile(testString);
+    QVERIFY(fromComponent->setProperty("aliasToOtherFile", testString));
+
+    QCOMPARE(fromQmltc.aliasToOtherFile(), testString);
+    QCOMPARE(fromComponent->property("aliasToOtherFile"), testString);
+}
+
 QTEST_MAIN(tst_qmltc)
diff --git a/tests/auto/qml/qmltc/tst_qmltc.h b/tests/auto/qml/qmltc/tst_qmltc.h
index 0eea63b0f2..eaa4bed27a 100644
--- a/tests/auto/qml/qmltc/tst_qmltc.h
+++ b/tests/auto/qml/qmltc/tst_qmltc.h
@@ -88,4 +88,5 @@ private slots:
     void generalizedGroupedProperty();
     void appendToQQmlListProperty();
     void inlineComponents();
+    void aliases();
 };