Buffer problem

[Hans Aberg]

I have a buffer problem with the scan-skel lexer that comes with Bison 2.0.
I use a special tweak, so it may have nothing to do with that program. After
scanning a little less than 8 kB, the scanner first ends up at end of buffer
EOB_ACT_LAST_MATCH, after which it rescans, scans a few character of the
current rule, the rescans, ending up end of buffer EOB_ACT_END_OF_FILE, then
terminating. Then number of character it dies at is always the same, even if
I change the input file. So it seems like a buffer problem. What might cause
it?