Warning from flockfile

[glebm]

Getting a compilation warning:

fmt/format-inl.h:1456:50: warning: argument 1 null where non-null expected [-Wnonnull]
 1456 | struct has_flockfile<F, void_t<decltype(flockfile(static_cast<F*>(nullptr)))>>
      |                                         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/13/cstdio:42,
                 from /usr/include/c++/13/ext/string_conversions.h:45,
                 from /usr/include/c++/13/bits/basic_string.h:4109,
                 from /usr/include/c++/13/string:54,
                 from /usr/include/c++/13/bits/locale_classes.h:40,
                 from /usr/include/c++/13/locale:41,
                 from /home/gleb/devilutionX/build/_deps/libfmt-src/include/fmt/format-inl.h:19:
/usr/include/stdio.h:941:13: note: in a call to function ‘void flockfile(FILE*)’ declared ‘nonnull’
  941 | extern void flockfile (FILE *__stream) __THROW __nonnull ((1));

The warning is spurious since this is in decltype. Maybe this should be considered a bug in GCC actually.

[vitaut]

This is a false positive because the call is in an unevaluated context. Please report to gcc.

[vitaut]

In any case, the warning should be suppressed in 92227c7.