Comment 2 for bug 1621002

This is looking like a case of the code being miscompiled under optimisation. To reproduce, build mediascanner2 using the "RelWithDebInfo" build type and then run:

    ./test/test_dbus --gtest_filter=*filter_codec

The test program segfaults when calling Variant::as<std::string>() on a variant that should have been initialised by reading out of a Message::Reader.

When compiling with the "Debug" build type, the test program completes without error.

I can probably solve the immediate problem in mediascanner2 by disabling optimisation for the affected file.