Your bug report

#7157: df should default to -P if output is not a tty

which was filed against the coreutils package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 7157@debbugs.gnu.org.

-- 
7157: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=7157
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