Fix crash when using aliases and variants

Right now, the parser crash when using id.variant.property for an alias.
The current patch fix the crash, and it displays an error message in
the console now (like QtQuick 2).

Task-number: QTBUG-25341
Change-Id: I5e2c13f487655fd2b90129c5693f5daf3f77984b
Reviewed-by: Matthew Vogt <matthew.vogt@nokia.com>

4 files changed, 12 insertions, 1 deletions

diff --git a/src/declarative/qml/qdeclarativevaluetype_p.h b/src/declarative/qml/qdeclarativevaluetype_p.h
index 5c2cda7..6666532 100644
--- a/src/declarative/qml/qdeclarativevaluetype_p.h
+++ b/src/declarative/qml/qdeclarativevaluetype_p.h
@@ -92,7 +92,7 @@ public:
     static void registerValueTypes();
 
     QDeclarativeValueType *operator[](int idx) const {
-        if (idx >= (int)QVariant::UserType) return 0;
+        if (idx < 0 || idx >= (int)QVariant::UserType) return 0;
         else return valueTypes[idx];
     }
 
diff --git a/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.errors.txt b/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.errors.txt
new file mode 100644
index 0000000..b94e92c
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.errors.txt
@@ -0,0 +1 @@
+8:25:Invalid alias location
diff --git a/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.qml b/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.qml
new file mode 100644
index 0000000..25efe28
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativelanguage/data/invalidAlias.11.qml
@@ -0,0 +1,9 @@
+import QtQuick 1.0
+
+QtObject {
+    id: main
+    property variant v: Text{
+        text: "variant text"
+    }
+    property alias foo: main.v.text
+}
diff --git a/tests/auto/declarative/qdeclarativelanguage/tst_qdeclarativelanguage.cpp b/tests/auto/declarative/qdeclarativelanguage/tst_qdeclarativelanguage.cpp
index bfc0a5f..c8f26d5 100644
--- a/tests/auto/declarative/qdeclarativelanguage/tst_qdeclarativelanguage.cpp
+++ b/tests/auto/declarative/qdeclarativelanguage/tst_qdeclarativelanguage.cpp
@@ -385,6 +385,7 @@ void tst_qdeclarativelanguage::errors_data()
     QTest::newRow("invalidAlias.8") << "invalidAlias.8.qml" << "invalidAlias.8.errors.txt" << false;
     QTest::newRow("invalidAlias.9") << "invalidAlias.9.qml" << "invalidAlias.9.errors.txt" << false;
     QTest::newRow("invalidAlias.10") << "invalidAlias.10.qml" << "invalidAlias.10.errors.txt" << false;
+    QTest::newRow("invalidAlias.11") << "invalidAlias.11.qml" << "invalidAlias.11.errors.txt" << false;
 
     QTest::newRow("invalidAttachedProperty.1") << "invalidAttachedProperty.1.qml" << "invalidAttachedProperty.1.errors.txt" << false;
     QTest::newRow("invalidAttachedProperty.2") << "invalidAttachedProperty.2.qml" << "invalidAttachedProperty.2.errors.txt" << false;