Disallow registration of types beginning with lowercase letters

Allowing types with lowercase names causes ambiguity, as can be seen in
QTBUG-43567 and the comment in IRBuilder::visit(), which explains that
"the grammar can't distinguish between two different definitions" whose
only difference is casing of the first letter.

- Prevent registration (return -1 with e.g. qmlRegisterType()) when a
  type name doesn't begin with an uppercase letter.
- Document the uppercase type name rule in more places.

Change-Id: I4e522c65990f418eaafa45a256e3cb07a3e01ba4
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 803bf0c468..83151fb6e2 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -271,6 +271,8 @@ private slots:
 
     void accessDeletedObject();
 
+    void lowercaseTypeNames();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -4596,6 +4598,12 @@ void tst_qqmllanguage::accessDeletedObject()
     QVERIFY(!o.isNull());
 }
 
+void tst_qqmllanguage::lowercaseTypeNames()
+{
+    QCOMPARE(qmlRegisterType<QObject>("Test", 1, 0, "lowerCaseTypeName"), -1);
+    QCOMPARE(qmlRegisterSingletonType<QObject>("Test", 1, 0, "lowerCaseTypeName", nullptr), -1);
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"