Fix a crash bug when using automatic authentication protocols such as SSPI.
Fix a crash bug when using automatic authentication protocols such as SSPI.

Neon automatically tries some auth protocols and bumps the attempt
count without using Subversion's callbacks, so we can't depend
on attempt == 0 the first time we are called.

Patch by: Stefan Kung <tortoisesvn@gmail.com>

* subversion/libsvn_ra_dav/session.c
  (request_auth): Don't depend on the attempt parameter being zero for
  the first auth callback we get from neon, just check the auth state itself.



git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@862514 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion