msautotest compare_result() function in testlib.py run the perceptualdiff command eventhough this is not an image file

[nsavard]

The perceptualdiff comparison in the compare_result() function of the msautotest (in testlib.py), occurs even though this is not an image file. I propose to add the following test to overcome this issue:

   result = open(result_file, "rb").read()

    #If PerceptualDiff is installed and this is an image file
    if have_pdiff != 'false' and \
       ('\x49\x49\x2A\x00' in result \
       or '\x49\x49\x00\x2A' in result \
       or '\x89\x50\x4e\x47\x0d\x0a\x1a\x0a' in result):

The complete code concerning the perceptualdiff comparison is shown below.

    ###################################################################
    # Test with perceptualdiff.  If we discover we don't have it, then
    # set have_pdiff to 'false' so we will know.
    
    global have_pdiff

    result = open(result_file, "rb").read()

    #If PerceptualDiff is installed and this is an image file
    if have_pdiff != 'false' and \
       ('\x49\x49\x2A\x00' in result \
       or '\x49\x49\x00\x2A' in result \
       or '\x89\x50\x4e\x47\x0d\x0a\x1a\x0a' in result):
 
        try:
            cmd = 'perceptualdiff %s %s > pd.out' % (result_file,expected_file)
            os.system( cmd )
            pdout = open('pd.out').read()
            os.remove( 'pd.out' )
            
            if string.find(pdout,'PASS:') != -1 \
               and string.find(pdout,'binary identical') != -1:
                return 'files_differ_image_match'
        
            if string.find(pdout,'PASS:') != -1 \
               and string.find(pdout,'indistinguishable') != -1:
                return 'files_differ_image_nearly_match'

            if string.find(pdout,'PASS:') == -1 \
               and string.find(pdout,'FAIL:') == -1:
                have_pdiff = 'false'

        except:
            pass
        
    return 'nomatch'

[warmerdam]

Normand,

Good approach! Applied in trunk in time for 5.6 (r9439).