[gentoo-portage-dev] [PATCH] Fix read only filesystem detection logic

[Bertrand Simonnet]

Hi everyone,

I think there is a bug in the read only detection logic: portage will check
the write permission on the system relative to / and not relative to ROOT.

I found this when emerging a package with --root=/usr/local on my system
with:
* / read only
* /usr/local read-write

Note, the error message was also wrong as it indicated that /usr/local was
read only when it actually detected / as read only and prefixed it with
ROOT in the message.

I attached a patch that fix the detection logic and the error message.

Bertrand Simonnet