wrap: be more robust with locale

On (some?) MacOS systems there is no C.UTF-8 locale available. Instead
there is a non-standard "UTF-8" (encoding only) replacement. Running
wrap on MacOS results in an error:

  error: failed to set locale: Bad file descriptor

Instead of expecting that C.UTF-8 will always be available, try to use
the user set locale (either from the $LC_ALL or $LANG environment
variables). If these variables are unset or if they are set to an
invalid/non-existent locale, fallback on C.UTF-8. If C.UTF-8 is not
available, make one last desperate attempt for this UTF-8 non-standard
locale (MacOS only).

aerc will always send UTF-8 encoded text to the filter commands, If the
locale that we managed to load does not use the UTF-8 character
encoding, exit with an explicit error instead of risking undefined
behaviour.

Reported-by: Ben Cohen <ben@bencohen.net>
Signed-off-by: Robin Jarry <robin@jarry.cc>

0 files changed, 0 insertions, 0 deletions