SdMiscTest::testTdf119956 failing on Windows

[Stephan Bergmann]

Does anybody happen to have an idea why making 
`CppunitTest_sd_misc_tests CPPUNIT_TEST_NAME=SdMiscTest::testTdf119956` 
reliably keeps failing on my Windows build with

> [_RUN_____] SdMiscTest::testTdf119956
> warn:sfx.appl:12952:11096:sfx2/source/appl/app.cxx:148: No DDE-Service possible. Error: 16399
> warn:vcl:12952:11096:vcl/win/window/salframe.cxx:1110: WinSalFrame::SetIcon(): Could not load large icon !
> warn:vcl:12952:11096:vcl/win/window/salframe.cxx:1111: WinSalFrame::SetIcon(): Could not load small icon !
> warn:basic:12952:11096:basic/source/uno/namecont.cxx:930: Cannot access extensions!
> warn:basic:12952:11096:basic/source/uno/namecont.cxx:930: Cannot access extensions!
> Dialog "Insert Layer" cancelled in silent mode
> C:/lo/core/sd/qa/unit/misc-tests.cxx:757:SdMiscTest::testTdf119956
> equality assertion failed
> - Expected: 3
> - Actual  : 0

(No idea whether any of the leading diagnostics might be relevant, 
though, just notice that at least on my Linux builds none of that is 
present, and the "Dialog ... cancelled in silent mode" message looks 
somewhat suspicious.  And no idea when this would actually have started 
to fail.)