Subject: bug#25223: chmod +w does not work

From: Paul Eggert <[email-masked]>
Date: Sun, 18 Dec 2016 11:15:21 -0800

Eugen Dedu wrote:
> Is there a rationale for this, i.e. chmod to use umask?

It's specified by POSIX. I expect the idea was to make it a bit harder to grant 
permissions that the user didn't intend.