Subject: avoid new gcc warning: ENOTSUP vs EOPNOTSUPP
From: Jim Meyering <[email-masked]>
To: [email-masked]
Date: Sat, 9 May 2015 11:15:07 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Building with very new gcc-from-git, I encountered 3 new warnings.
Here's a patch to address them:

Without this change, very recent gcc (e.g., version 6.0.0 20150509)
would print the following when configured with --enable-gcc-warnings:

  src/copy.c:165:30: error: logical 'or' of equal expressions \
    [-Werror=logical-op]
    && (errno == EOPNOTSUPP || errno == ENOTSUP || errno == ENOSYS))
                           ^
* src/system.h (is_ENOTSUP): New function.
* src/copy.c (punch_hole): Use it.
* src/ls.c (errno_unsupported, gobble_file): Use it.