The bug was fixed, the reasone of crash is following. The Core Flow view
contain another GL context and will not care about restoring a previous.
I restore context manually.
This path also contain a minor changes in another files.

All changes described here.

Сhange's for fix current bug.
indra/llwindow/llwindow.h
indra/llwindow/llwindowheadless.h
indra/llwindow/llwindowmacosx.h
indra/llwindow/llwindowsdl.h
indra/llwindow/llwindowwin32.h
indra/newview/lllocalbitmaps.cpp
indra/newview/llviewerdisplay.cpp
indra/newview/llviewerdisplay.h

Twice mUsage initialization (replace to forward initialization).
indra/llcharacter/lljointstate.h

Looks like condition should be befor memcopy call, otherwise - possible CRASH.
indra/llcommon/llmd5.cpp

Unused condition and variables.
indra/llmath/llsphere.cpp

Looks like should be under if otherwise - possible CRASH
indra\llprimitive\llmodel.cpp

Useless assert's.
indra/llrender/llrender.cpp
indra/newview/lldaycyclemanager.cpp