What is broken is detailed at <http://cgit.freedesktop.org/libreoffice/core/commit/?id=3bafe5f5f529f6539363c5a291dd13ef1e2cbbde> "Extension shared library components must not use the 'prefix' feature," along with a fix of the problem, for which I also requested backports to libreoffice-4-1 (<https://gerrit.libreoffice.org/#/c/6209/>) and libreoffice-4-1-3 (<https://gerrit.libreoffice.org/#/c/6210/>).
A further reason I'm so panicky about not distributing any broken versions is that there are cooking up changes to the UNO component "prefix" feature that would make it desirable that no non-bundled extension ever used that "prefix" feature.
In the wild, I find:* <http://extensions.libreoffice.org/extension-center/mysql-native-connector-for-libreoffice-4.x> "MySQL Native Connector for LibreOffice 4.x" from an UNKNOWN UPLOADER, which only offers <http://extensions.libreoffice.org/extension-center/mysql-native-connector-for-libreoffice-4.x/releases/1.0/mysql-connector-ooo.oxt> which is apparently too old to be affected.
* <http://extensions.libreoffice.org/extension-center/mysql-native-connector> "MySQL Native Connector" from an UKNOWN UPLOADER which only offers <http://extensions.libreoffice.org/extension-center/mysql-native-connector/releases/1.0/mysql-native-connector-32-bit/view> and <http://extensions.libreoffice.org/extension-center/mysql-native-connector/releases/1.0/mysql-native-connector-64-bit/view> which both are apparently too old to be affected.
* <http://sourceforge.net/projects/lomysqlconnectorextension/> by Alex Thurgood, which /is/ affected. Alex, can you make available a fixed build there, either off master past <http://cgit.freedesktop.org/libreoffice/core/commit/?id=3bafe5f5f529f6539363c5a291dd13ef1e2cbbde> or off libreoffice-4-1 past pending integration of <https://gerrit.libreoffice.org/#/c/6209/>?
Andreas, can you contact the uploaders of the two extensions marked "UNKNOWN UPLOADER" above, to make sure they do not inadvertently upload broken versions?
Thanks, Stephan