6a8fd4c7 claims that RescheduleDuringAcquire is
necessary to prevent deadlocks, but fails to explain what those deadlocks look
like (and the cited HH internal issue 163542 is not available for inspection).
It does lead to code erroneously being called with unlocked solar mutex, leading
to crashes like

Thread 1:
 0  in com::sun::star::uno::BaseReference::is at solver/unxlngx6/inc/com/sun/star/uno/Reference.h:103
 1  in sdr::contact::ControlHolder::is at svx/source/sdr/contact/viewobjectcontactofunocontrol.cxx:204
 2  in sdr::contact::ViewObjectContactOfUnoControl_Impl::hasControl at svx/source/sdr/contact/viewobjectcontactofunocontrol.cxx:642
 3  in sdr::contact::ViewObjectContactOfUnoControl::isPrimitiveVisible at svx/source/sdr/contact/viewobjectcontactofunocontrol.cxx:1815
 4  in sdr::contact::ViewObjectContact::getPrimitive2DSequenceHierarchy at svx/source/sdr/contact/viewobjectcontact.cxx:396
 5  in sdr::contact::ViewObjectContact::getPrimitive2DSequenceSubHierarchy at svx/source/sdr/contact/viewobjectcontact.cxx:428
 6  in sdr::contact::ViewObjectContactOfPageHierarchy::getPrimitive2DSequenceHierarchy at svx/source/sdr/contact/viewobjectcontactofsdrpage.cxx:450
 7  in sdr::contact::ViewObjectContact::getPrimitive2DSequenceSubHierarchy at svx/source/sdr/contact/viewobjectcontact.cxx:428
 8  in sdr::contact::ViewObjectContactOfSdrPage::getPrimitive2DSequenceHierarchy at svx/source/sdr/contact/viewobjectcontactofsdrpage.cxx:699
 9  in sdr::contact::ObjectContactOfPageView::DoProcessDisplay at svx/source/sdr/contact/objectcontactofpageview.cxx:248
 10 in sdr::contact::ObjectContactOfPageView::ProcessDisplay at svx/source/sdr/contact/objectcontactofpageview.cxx:132
 11 in SdrPageWindow::RedrawLayer at svx/source/svdraw/sdrpagewindow.cxx:391
 12 in SdrPageView::DrawLayer at svx/source/svdraw/svdpagv.cxx:398
 13 in SwViewImp::PaintLayer at sw/source/core/view/vdraw.cxx:148
 14 in SwRootFrm::Paint at sw/source/core/layout/paintfrm.cxx:2976
 15 in ViewShell::Paint at sw/source/core/view/viewsh.cxx:1678
 16 in SwCrsrShell::Paint at sw/source/core/crsr/crsrsh.cxx:1165
 17 in SwEditWin::Paint at sw/source/ui/docvw/edtwin2.cxx:535
 18 in Window::ImplCallPaint at vcl/source/window/window.cxx:2417
 19 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 20 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 21 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 22 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 23 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 24 in Window::ImplCallPaint at vcl/source/window/window.cxx:2441
 25 in Window::ImplCallOverlapPaint at vcl/source/window/window.cxx:2477
 26 in Window::ImplHandlePaintHdl at vcl/source/window/window.cxx:2497
 27 in Window::LinkStubImplHandlePaintHdl at vcl/source/window/window.cxx:2491
 28 in Link::Call at solver/unxlngx6/inc/tools/link.hxx:140
 29 in Timer::Timeout at vcl/source/app/timer.cxx:256
 30 in Timer::ImplTimerCallbackProc at vcl/source/app/timer.cxx:144
 31 in SalTimer::CallCallback at vcl/inc/saltimer.hxx:66
 32 in SvpSalInstance::CheckTimeout at vcl/headless/svpinst.cxx:199
 33 in SvpSalInstance::Yield at vcl/headless/svpinst.cxx:310
 34 in ImplYield at vcl/source/app/svapp.cxx:455
 35 in Application::Reschedule at vcl/source/app/svapp.cxx:482
 36 in SolarMutexReleaser::~SolarMutexReleaser at solver/unxlngx6/inc/vcl/svapp.hxx:551
 37 in VCLXWindowImpl::OnProcessCallbacks at toolkit/source/awt/vclxwindow.cxx:320
 38 in VCLXWindowImpl::LinkStubOnProcessCallbacks at toolkit/source/awt/vclxwindow.cxx:291
 39 in Link::Call at solver/unxlngx6/inc/tools/link.hxx:140
 40 in ImplHandleUserEvent at vcl/source/window/winproc.cxx:1999
 41 in ImplWindowFrameProc at vcl/source/window/winproc.cxx:2571
 42 in SalFrame::CallCallback at vcl/inc/salframe.hxx:294
 43 in SvpSalInstance::Yield at vcl/headless/svpinst.cxx:299
 44 in ImplYield at vcl/source/app/svapp.cxx:455
 45 in Application::Yield at vcl/source/app/svapp.cxx:489
 46 in Application::Execute at vcl/source/app/svapp.cxx:432
 47 in desktop::Desktop::Main at desktop/source/app/app.cxx:1824
 48 in ImplSVMain at vcl/source/app/svmain.cxx:178
 49 in SVMain at vcl/source/app/svmain.cxx:215
 50 in soffice_main at desktop/source/app/sofficemain.cxx:67
 51 in sal_main at desktop/source/app/main.c:34
 52 in main at desktop/source/app/main.c:33

Thread 2:
 0  __lll_unlock_wake at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:373
 1  in _L_unlock_657 from /lib64/libpthread-2.12.so
 2  in __pthread_mutex_unlock_usercnt at pthread_mutex_unlock.c:52
 3  __pthread_mutex_unlock at pthread_mutex_unlock.c:290
 4  in osl_releaseMutex at sal/osl/unx/mutex.c:179
 5  in vcl::SolarMutexObject::release at vcl/source/app/solarmutex.cxx:54
 6  in SalYieldMutex::release at vcl/generic/app/geninst.cxx:73
 7  in SolarMutexGuard::~SolarMutexGuard at solver/unxlngx6/inc/vcl/svapp.hxx:436
 8  in SfxBaseModel::close at sfx2/source/doc/sfxbasemodel.cxx:1500
 9  in SwXTextDocument::close at sw/source/ui/uno/unotxdoc.cxx:574
 10 in callVirtualMethod at bridges/source/cpp_uno/gcc3_linux_x86-64/uno2cpp.cxx:155
 11 in cpp_call at bridges/source/cpp_uno/gcc3_linux_x86-64/uno2cpp.cxx:392
 12 in bridges::cpp_uno::shared::unoInterfaceProxyDispatch at bridges/source/cpp_uno/gcc3_linux_x86-64/uno2cpp.cxx:586
 13 in binaryurp::IncomingRequest::execute_throw at binaryurp/source/incomingrequest.cxx:263
 14 in binaryurp::IncomingRequest::execute at binaryurp/source/incomingrequest.cxx:89
 15 in binaryurp::(anonymous namespace)::request at binaryurp/source/reader.cxx:107
 16 in cppu_threadpool::JobQueue::enter at cppu/source/threadpool/jobqueue.cxx:121
 17 in cppu_threadpool::ORequestThread::run at cppu/source/threadpool/thread.cxx:222
 18 in cppu_requestThreadWorker at cppu/source/threadpool/thread.cxx:57
 19 in osl_thread_start_Impl at sal/osl/unx/thread.c:292
 20 in start_thread at pthread_create.c:301
 21 in clone at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Looks best to remove that strange feature again and, if deadlocks should
resurface, how to fix them cleanly.