Undefined behavior or sanitizer bug ?

[rockdaboot]

oss-fuzz reports an undefined behavior in nettle, a dependency of gnutls:

SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
/src/libfuzzer/FuzzerSHA1.cpp:132:14 in
        sec-tabselect.c:58:24: runtime error: negation of 1 cannot be represented in type 'mp_limb_t' (aka 'unsigned long')

The corresponding C line is

mp_limb_t mask = - (mp_limb_t) (k == 0);

The author of nettle, Niels Möller, arguments against fixing, saying this is not UB.
Please check out his arguments to see if this is indeed UB or a bug in clang's sanitizer.
http://lists.lysator.liu.se/pipermail/nettle-bugs/2017/003387.html

[kcc]

negation of unsigned integer 1 is clearly defined and is not a bug (unless you want to treat it as such).
What's the bug report where this happens?

[rockdaboot]

Last week under 'All current crashes' I was displayed 4-5 pages of fixed and unfixed issues (many had no issue number btw). Today, I see one page and the above mentioned one is missing.

Maybe this was just a glitch or remnants from some tests on oss-fuzz' side. That SUMMARY line mentioned above is copied from that bug report.

Anyways, I close this issue since it seems to be irrelevant currently.
Thanks for taking a look.