[Debian-med-packaging] Bug#907624: Help for SIGSEGV in test suite needed when built with gcc 8.2 what works nicely with gcc 6.3

[Yavor Doganov]

On Wed, 09 Jan 2019 22:42:43 +0200,
Andreas Tille wrote:
> The values of the structure are set in line 350[3] and are OK there.

What looks suspicious to me is that an unsigned long long value is
assigned to struct members of type size_t.  In the previous upstream
release that worked, the return value of ffparse_ulong was used which
was unsigned long.

I doubt this is the culprit but may be something worth looking at.

> I admit I fail to see why the code works under stretch with gcc 6.3
> but fails with gcc 8.2.

If the code works with an old compiler but fails with a modern one, in
99.99% of the cases it's a bug in the code.  These bugs are revealed
due to new and more aggressive optimization techniques/algorithms that
assume undefined behavior.  IOW, the code was/is buggy by definition
but you got away with it somehow.  The remaining 0.01% is due to
compiler bugs but I bet that's not the case here.