[pdf-devel] more notes on pdf-stm-f-a85.c

[Cirilo Bernardo]

Yet more comments on the ASCII85 decoder:

1.  There is no overflow check (maximum 5-tuple should be 's8W-!', but
there are more efficient means of checking for an overflow as the
result is calculated).

2.  The memory handling is insufficient; in the current implementation
it is trivial to overflow the allocated memory - for example, just
make the input "zzz~>" - a perfectly valid stream.

- Cirilo