base-files: remove ending colon from default $PATH for root user
now the PATH for root user defined in a problematic way
PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin:
from eglibc:
/* Two adjacent colons, or a colon at the beginning or the end
of `PATH' means to search the current directory. */
that means current directory is always searched as the last path,
which could generate undesired behavior.
One example is found in LTP cron_deny01 test, which always complains
"sh: cron_deny01 not found"
cron_deny01 is a shell script which setups the initial test preparation
and then invokes itself for real test under a different user:
su $TEST_USER1 -c "$0"
'su' doesn't inherit PATH into the sub-shell, and thus $0 has to
be an absolute path to have right script found.
ltp appends the path of cron_deny01 to $PATH before running the test:
export PATH="${PATH}:${LTPROOT}/testcases/bin"
In ideal way "${LTPROOT}/testcases/bin/cron_deny01" is found and becomes
$0, which works well.
However due to the ending colon in original PATH:
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin::${LTPROOT}/testcases/bin
$0 becomes 'cron_deny01' w/o leading path which makes sub-shell under 'su'
failed to locate cron_deny01.
