QVariant: fix conversions of string keys to Q_ENUM that are QFlags<>

Since Qt 6.0, QMetaType stores the name obtained from the C++ compiler,
which means we know a type like Qt::Alignment by its proper, full name
of QFlags<Qt::AlignmentFlag>. However, the meta object records only the
bare name of the enumeration, not the full flags.

Pick-to: 6.2 6.3 6.4
Fixes: QTBUG-105932
Fixes: QTBUG-96185
Change-Id: Ic6547f8247454b47baa8fffd170eab977e306377
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 11 insertions, 5 deletions

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index e4ef2f7665..927c258647 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -1871,10 +1871,16 @@ static QMetaEnum metaEnumFromType(QMetaType t)
 {
     if (t.flags() & QMetaType::IsEnumeration) {
         if (const QMetaObject *metaObject = t.metaObject()) {
-            const QByteArray enumName = t.name();
-            const char *lastColon = std::strrchr(enumName, ':');
-            return metaObject->enumerator(metaObject->indexOfEnumerator(
-                    lastColon ? lastColon + 1 : enumName.constData()));
+            QByteArrayView qflagsNamePrefix = "QFlags<";
+            QByteArray enumName = t.name();
+            if (enumName.endsWith('>') && enumName.startsWith(qflagsNamePrefix)) {
+                // extract the template argument
+                enumName.chop(1);
+                enumName = enumName.sliced(qflagsNamePrefix.size());
+            }
+            if (qsizetype lastColon = enumName.lastIndexOf(':'); lastColon != -1)
+                enumName = enumName.sliced(lastColon + 1);
+            return metaObject->enumerator(metaObject->indexOfEnumerator(enumName));
         }
     }
     return QMetaEnum();
@@ -2524,7 +2530,7 @@ bool QMetaType::canConvert(QMetaType fromType, QMetaType toType)
             return true;
     }
     const ConverterFunction * const f =
-        customTypesConversionRegistry()->function(qMakePair(fromTypeId, toTypeId));
+        customTypesConversionRegistry()->function(std::make_pair(fromTypeId, toTypeId));
     if (f)
         return true;