Correct two more corner case problems with #1486: 1) single-page streams will have no bisection; handle the special case explicitly 2) if the bisection fails without ever successfully grabbing a page, the first-page-special-case check is unprotected and will look at uninitialized memory.
Correct two more corner case problems with #1486:
1) single-page streams will have no bisection; handle the special case explicitly
2) if the bisection fails without ever successfully grabbing a page, the first-page-special-case check is unprotected and will look at uninitialized memory.


svn path=/trunk/vorbis/; revision=19171

nicolaichuk/vorbis,youfearm3/vorbis,erikd/vorbis,eidy/vorbis,felipebetancur/vorbis,ShiftMediaProject/vorbis,eidy/vorbis,nicolaichuk/vorbis,erikd/vorbis,ShiftMediaProject/vorbis,emscripten-ports/Vorbis,emscripten-ports/Vorbis,youfearm3/vorbis,ShiftMediaProject/vorbis,nicolaichuk/vorbis,eidy/vorbis,mwgoldsmith/vorbis,emscripten-ports/Vorbis,mwgoldsmith/vorbis,eidy/vorbis,ShiftMediaProject/vorbis,mwgoldsmith/vorbis,youfearm3/vorbis,youfearm3/vorbis,ShiftMediaProject/vorbis,mwgoldsmith/vorbis,erikd/vorbis,ShiftMediaProject/vorbis,felipebetancur/vorbis,erikd/vorbis,ksophocleous/vorbis,emscripten-ports/Vorbis,ksophocleous/vorbis,felipebetancur/vorbis,felipebetancur/vorbis,ksophocleous/vorbis,ksophocleous/vorbis,nicolaichuk/vorbis