Fix memory corruption with type trimming

When creating a composite type, we register the meta-type in the qml
loader thread. However we would require linking of the compilation unit
to the QML/engine thread before we would be able to also undo that
registration in unlink(), because we require the engine member to be
set. If that did not happen, i.e. a qml type was loaded and trimmed from
the cache before it was ever linked, we would end up with a dangling
pointer in m_compositeTypes.

Let's handle the case of CompilationUnit referring to a QML composite
type separately from it being a compilation unit resulting from a .js
file or in a plain QJSEngine environment.

Task-number: QTBUG-62630
Change-Id: Ia68cc46f05345702bd9ba0378f61118f1964d141
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index efa4ed2f79..84410875ab 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -2295,7 +2295,7 @@ void QQmlTypeData::done()
             }
         }
 
-        m_compiledData->finalize(enginePrivate);
+        m_compiledData->finalizeCompositeType(enginePrivate);
     }
 
     {