Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
later.
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].
A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)
This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).
[0]: http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man3/calloc.3
This is a particularly interesting program.
I managed to implement everything according to POSIX except how
octal escapes are specified in the standard, which is yet another
format compared to the one demanded for tr(1).
This not only confuses people, it also adds unnecessary cruft
for no real gain.
So in order to be able to use unescape() easily and for consistency,
I used our initial format \o[oo] instead of \0[ooo].
Marked as optional is UTF-8 support for %c in the POSIX specification.
Given how well-developed libutf has become, doing this here was more
or less trivial, putting us yet again ahead of the competition.
