Subject: [PATCH 0/1] tty: do not provide conflicting information
From: Christian Brauner <[email-masked]>
To: [email-masked], [email-masked], [email-masked], [email-masked]
Cc: Christian Brauner <[email-masked]>
Date: Wed, 5 Apr 2017 16:44:40 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

Hi guys,

In case the current file descriptor is a tty but ttyname{_r}() fails to retrieve
the device path tty would falsely report "not a tty" but return EXIT_SUCCESS.
This is confusing. Instead, let's first check whether the fd refers to a tty and
if not report "not a tty" and exit with error. In all other cases, we should
report "is a tty but failed to determine the device path" and exit with success.
This is much clearer. Depending on the platform the user can then decide how to
proceed, e.g. by looking at /proc/self/fd/0 for Linux or somewhere else on other
platforms.

This becomes especially important when we deal with Linux namespaces where this
case can regularly happen should a new devpts instance be mounted in the
namespace but the fd still refers to a pts device from another devpts instance
in another mount namespace.

I added Signed-off-by line but I'm not completely sure if this is used in
cureutils. If not, just drop it. :)

Christian

Christian Brauner (1):
  tty: do not provide conflicting information

 src/tty.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

-- 
2.11.0