sw: fix use-after-free in SwAccessibleMap::FireEvents()
As seen when running JunitTest_sw_unoapi_3 against "make debugrun",
the damn thing can call itself recursively via an odd corner case in
GetContext():
0 in SwAccessibleEventList_Impl::~SwAccessibleEventList_Impl() (this=0x9a6a170, __in_chrg=<optimized out>) at sw/source/core/access/accmap.cxx:498
1 in SwAccessibleMap::FireEvents() (this=0x8198bb0) at sw/source/core/access/accmap.cxx:3023
2 in SwAccessibleMap::InvalidateCursorPosition(com::sun::star::uno::Reference<com::sun::star::accessibility::XAccessible> const&) (this=0x8198bb0, rAcc=uno::Reference to (SwAccessibleParagraph *) 0x9a439d8) at sw/source/core/access/accmap.cxx:1069
3 in SwAccessibleMap::GetContext(SwFrame const*, bool) (this=0x8198bb0, pFrame=0x825ca10, bCreate=true) at sw/source/core/access/accmap.cxx:1925
4 in SwAccessibleMap::GetContextImpl(SwFrame const*, bool) (this=0x8198bb0, pFrame=0x825ca10, bCreate=true) at sw/source/core/access/accmap.cxx:1936
5 in SwAccessibleContext::InvalidateChildPosOrSize(sw::access::SwAccessibleChild const&, SwRect const&) (this=0x405a350, rChildFrameOrObj=..., rOldFrame=SwRect = {...}) at sw/source/core/access/acccontext.cxx:1196
6 in SwAccessibleMap::FireEvent(SwAccessibleEvent_Impl const&) (this=0x8198bb0, rEvent=...) at sw/source/core/access/accmap.cxx:898
7 in SwAccessibleMap::FireEvents() (this=0x8198bb0) at sw/source/core/access/accmap.cxx:3018
8 in SwViewShellImp::FireAccessibleEvents() (this=0x7744dc0) at sw/source/core/view/viewimp.cxx:460
9 in SwLayIdle::SwLayIdle(SwRootFrame*, SwViewShellImp*) (this=0x7ffc63395e30, pRt=0x7745120, pI=0x7744dc0) at sw/source/core/layout/layact.cxx:2267
Presumably all of mpEvents, mpEventMap and mpShapes must live until
the outermost FireEvents() completes.
Change-Id: I4e5a053035bf7fc12d9407913437d721889950ae
diff --git a/sw/source/core/access/accmap.cxx b/sw/source/core/access/accmap.cxx
index 3c328fd..0a033792 100644
--- a/sw/source/core/access/accmap.cxx
+++ b/sw/source/core/access/accmap.cxx
@@ -3010,6 +3010,11 @@ void SwAccessibleMap::FireEvents()
osl::MutexGuard aGuard( maEventMutex );
if( mpEvents )
{
if (mpEvents->IsFiring())
{
return; // prevent recursive FireEvents()
}
mpEvents->SetFiring();
mpEvents->MoveMissingXAccToEnd();
for( auto const& aEvent : *mpEvents )
