bug#18580: [PATCH] dfa: check end of an input buffer after a transition in non-UTF8 multibyte locales

[Paul Eggert]

Thanks for catching that.  Obviously the patch should go in, but I'm mystified 
as to why we need two bytes' worth of sentinels after the buffer.  I suspect 
there's another bug lurking in there, related to the bugs earlier in this report.

That is, the two-byte trailing sentinel seems to be related to the problem that 
the code that calls transit_state_singlebyte can jump over two bytes when it 
should jump past just one.  The whole area is a bit of a mess.  (For example, 
transit_state_singlebyte always returns the same value -- what's up with that!?)