This crash was discovered by Dalai and this happened because of
unset current context (as result of call wglMakeCurrent(NULL, NULL)).
In this case glGetString(GL_VENDOR) returns NULL. Rather than add check
for vendor != NULL before string comparison, I've changed a bit logic of
context creation:
- Create context and set it as current
- If it's crappy Intel card -- delete this context and
share the only one context between all Windows
- Otherwise, use initial logic (with sharing lists and so on)
This could also fix crash when opening userprefs from a menu with Intel card.
e210d82f17