bug#55212: GNU Linux "sort -g" can hang indefinitely when run on standard input if NaNs are involved

[Paul Eggert]

Thanks for the bug report. This bug is entertaining, as it comes from 
GCC now being so smart that it optimizes away a memset that cleared 
padding bits. We added the memset in coreutils 8.14 (2011) to try to fix 
the sort -g infinite loop bug (introduced in 1999), but the memset isn't 
guaranteed to fix the bug because the memset can be optimized away.

If the padding bits happen to be clear already sort is OK, but if not 
the results can be inconsistent when you compare two NaNs to each other, 
and inconsistent results can make sort infloop.

The C standard allows this level of intelligence in the compiler, so 
it's a bug in GNU 'sort'.

I installed the attached patch; please give it a try. For now I'll 
boldly close the bug report; we can easily reopen it if this patch 
doesn't actually fix the problem.

0001-sort-fix-sort-g-infloop-again.patch
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