shiboken6: Fix inheriting template fields

562edc619787d83b2d4418fa7a69c597a7b6945c changing
AbstractMetaClass::fields() to return const-ref
introduced a bug causing inherited fields of the same name
to be rejected since they were added to the list.
Take a copy of the field list to fix this,
similar to d72f0e35f22f3f9460d12e40f8f5676bf5a7f0d1
for functions.

Change-Id: I4c7c4938dc4b3515a51ed0a161b4fc8c95d4f141
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 3 insertions, 2 deletions

diff --git a/sources/shiboken6/ApiExtractor/abstractmetabuilder.cpp b/sources/shiboken6/ApiExtractor/abstractmetabuilder.cpp
index f7c7f1292..96316b128 100644
--- a/sources/shiboken6/ApiExtractor/abstractmetabuilder.cpp
+++ b/sources/shiboken6/ApiExtractor/abstractmetabuilder.cpp
@@ -2709,14 +2709,15 @@ void AbstractMetaBuilderPrivate::inheritTemplateFunctions(AbstractMetaClass *sub
         subclass->addFunction(f.take());
     }
 
-    const AbstractMetaFieldList &subClassFields = subclass->fields();
+     // Take copy
+    const AbstractMetaFieldList existingSubclassFields = subclass->fields();
     const AbstractMetaFieldList &templateClassFields = templateClass->fields();
     for (const AbstractMetaField *field : templateClassFields) {
         // If the field is modified or the instantiation has a field named
         // the same as an existing field we have shadowing, so we need to skip it.
         if (field->isModifiedRemoved(TypeSystem::All)
             || field->attributes().testFlag(AbstractMetaAttributes::Static)
-            || AbstractMetaField::find(subClassFields, field->name()) != nullptr) {
+            || AbstractMetaField::find(existingSubclassFields, field->name()) != nullptr) {
             continue;
         }