set QTC_LOOKUPCONTEXT_DEBUG=1

Run qtcreator -test CppTools,test_completion:direct_nested_template_type_access

It crashes.

The problem is that in ResolveExpression::visit(SimpleNameAST *ast) a temporary document is created, and when it is destroyed with its control, the template name that was stored in the binding is destroyed with it, leaving a dangling pointer.

This might affect other use-cases even when debugging is disabled, since this name is stored in ClassOrNamespace::_templateId.