Plugin mimetypes XML can crash qtcreator

I faced some cryptic crashed when I'm developing new plugin. I fund that it's cased by a bad mimetypes xml loaded for the plugin.

When you use the same string for mimetype and sub-class the inifinite recursion starts when I open Tools/Preferences.

It is not a really critical issue but I'd expect something like "cannot load plugin" warning instead of real crash:
SIGSEV

0 QBasicAtomicOps<4>::ref<int> qatomic_x86.h 181 0x7fffe3aef2ed
1 QBasicAtomicInteger<int>::ref qbasicatomic.h 135 0x7fffe3aef1ec
2 QtPrivate::RefCount::ref qrefcount.h 63 0x7fffe3aeece8
3 QString::QString qstring.h 815 0x7fffe3aef018
4 Core::MimeType::type mimedatabase.cpp 693 0x7fffe3bc0fe7
5 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2218 0x7fffe3b42c08
6 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
7 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
8 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
9 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
10 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
11 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
12 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
13 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
14 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
15 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
16 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
17 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
18 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
19 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
20 mimeTypeFactoryRecursion<Core::IEditorFactory> editormanager.cpp 2236 0x7fffe3b42dd2
... <More>

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>

... snip ...
<mime-type type="text/x-qorus-qclass">
<sub-class-of type="text/x-qorus-qclass"/> <-- this should be eg. text/plain
<comment>Qorus class</comment>
<glob pattern="*.qclass"/>
</mime-type>

... snip ...

</mime-info>