Before commit 7dc24868, when process.env was nil, prepareEnv
returned a flag telling HOME is not set, and it was added.
Commit 7dc24868 moved the functionality of adding HOME into
prepareEnv but did not properly handle nil case. As a result,
runc exec -p with process.json having no env set resulted in
an exec with no HOME set.
Fix this, and add unit and integration tests.
Fixes: 7dc24868 ("libct: switch to numeric UID/GID/groups")
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
All existing tests check runc run, and there is no single runc exec
environment test except for one in exec.bats.
Add it (no new issues found).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>