Strip out nonprintable characters from xml (#670)

Some test somewhere is generating an error message
with ANSI codes: ^[[91mpermission denied. This is
making Jenkins choke with invalid XML.

Strip off chars not in ``string.printable`` in production of the XML
data.  The autotest and client logs preserve the erroneous output
if inspecting it later is needed.  This is just about getting the
XML correct.

Signed-off-by: Ed Santiago <[email protected]>

Author: edsantiago

results2junit

@@ -10,6 +10,7 @@ file suitable by Jenkins.
 import argparse
 import os
 import re
+import string
 import sys
 import time
 
@@ -39,7 +40,9 @@ def xml_escape(input_string):
     s_out = s_out.replace('<', '&lt;')
     s_out = s_out.replace('>', '&gt;')
     s_out = s_out.replace('"', '&quot;')
-    return s_out
+
+    # Strip out nonprintable characters, e.g. escape sequences.
+    return ''.join(c for c in s_out if c in string.printable)
 
 
 class TestSuite(object):