Bug 1037809

Description of problem:
With the fixes to the default user file-creation mask introduced by bug 1024526, the rhq-agent.sh or rhq-agent-wrapper.sh now produce undesired and possibly confusing output in the event that RHQ_AGENT_UMASK is not set/defined.

Version-Release number of selected component (if applicable):
3.2.0

How reproducible:
Always

Steps to Reproduce:
1. Install JBoss ON system
2. Update rhq-agent-env.sh to remove RHQ_AGENT_UMASK
   Alternatively, it can be changed from:
       RHQ_AGENT_UMASK=007
   To:
       RHQ_AGENT_UMASK=
3. Start agent.

Actual results:
        0002
        Starting RHQ Agent...

Expected results:
        Starting RHQ Agent...

Additional info:
This is because the command `umask` without parameters prints the current effective user file-creation mask.

As with any user definable value, basic data validation should be performed to ensure that this value can be used. A more suitable change may be something like:

# set a default if not already set
[ -z "${RHQ_AGENT_UMASK}" ] && RHQ_AGENT_UMASK=007

# when we actually go to use it, make sure it is actually set
[ ! -z "${RHQ_AGENT_UMASK}" ] && umask ${RHQ_AGENT_UMASK}

An even better option would be something like:

# set a default if not already set
[ -z "${RHQ_AGENT_UMASK}" ] && RHQ_AGENT_UMASK=007
umask ${RHQ_AGENT_UMASK} >/dev/null || {
    echo >&2 "RHQ_AGENT_UMASK contains an invalid umask value of [${RHQ_AGENT_UMASK}]"
}