Description of problem:

   When I start yumex, I get the error:  Yum Extender is already started"
   when it is provably NOT running.  I don't always get this immediately after
   logging in, but once I start getting it, I always get it.

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

   yumex-3.0.12-1.fc19.noarch

How reproducible:

   100% once it occurs

Steps to Reproduce:
1.Try to run yumex as myself (not as root).  I haven't tried running as root.
2.
3.

Actual results:

    Yumex doesn't run

Expected results:

    Yumex runs

Additional info:

I looked at the code and did some experimentation.  The problem is a false positive.  Yumex runs this code:

    ps = subprocess.Popen("ps -eaf | grep yumex", shell=True, stdout=subprocess.PIPE)
 
When I get this error, yumex gets two lines with the string "yumex" from the ps -eaf line.  One from the yumex invocation and one from the "grep yumex" request.  The second ilne should be ruled out by this check later in the function:

   for line in output.split('\n'):
        if '/usr/bin/yumex' in line or 'yumex.py' in line:
            cnt += 1
  
however, the "grep yumex" line contains the environment variable _=/usr/bin/yumex which gives a false positive match to the "if".  It appears the _ environment variable contains the name of the previous program that was run.

If I just add a single blank in front of the string '/usr/bin/yumex' (in line 39 of /usr/bin/yumex) then the false positive is avoided and yumex runs.  Whether bash is providing the wrong value for _ or not, this change is logical, correct, and avoids the false positive.  In the "ps -eaf" output, there will always be a blank before a valid instance of /usr/bin/yumex.

Here is the complete function (for context), with only one line changed:


def check_yumex_is_running():
    '''
    Check if other instances of yum is running
    '''
    ps = subprocess.Popen("ps -eaf | grep yumex", shell=True, stdout=subprocess.PIPE)
    output = ps.stdout.read()
    ps.stdout.close()
    ps.wait()
    cnt = 0
    for line in output.split('\n'):
        if ' /usr/bin/yumex' in line or 'yumex.py' in line:
            cnt += 1
    return cnt > 1