Deal with iLO bugs that cause non-ascii data in XML

The data returned by the iLO must be ascii-only, with non-ascii
characters replaced with xml charrefs. Unfortunately, this is not done
consistently. FOr example, the serial number is not escaped, but put in
raw, so if the serialnumber is broken (I've had reports of it being set
to U+0090), the XML is broken. Work around this by detecting non-ascii
data, replacing that data and warning if we do so.

hpilo.py

@@ -3,6 +3,7 @@
 
 __version__ = "3.7"
 
+import codecs
 import os
 import errno
 import platform
@@ -111,6 +112,22 @@ def _write(self, file, node, encoding, namespaces):
 else:
     raise RuntimeError("Don't know how to monkeypatch XML serializer workarounds. Please report a bug at https://github.com/seveas/python-hpilo")
 
+# We handle non-ascii characters in the returned XML by replacing them with XML
+# character references. This likely results in bogus data, but avoids crashes.
+# The iLO should never do this, but firmware bugs may cause it to do so.
+def iloxml_replace(error):
+    ret = ""
+    for pos in range(error.start, len(error.object)):
+        b = error.object[pos]
+        if not isinstance(b, int):
+            b = ord(b)
+        if b < 128:
+            break
+        ret += u'?'
+    warnings.warn("Invalid ascii data found: %s, replaced with %s" % (repr(error.object[error.start:pos]), ret), IloWarning)
+    return (ret, pos)
+codecs.register_error('iloxml_replace', iloxml_replace)
+
 # Which protocol to use
 ILO_RAW  = 1
 ILO_HTTP = 2
@@ -222,7 +239,7 @@ def __str__(self):
 
     def _debug(self, level, message):
         if message.__class__.__name__ == 'bytes':
-            message = message.decode('latin-1')
+            message = message.decode('ascii')
         if self.debug >= level:
             if self._protect_passwords:
                 message = re.sub(r'PASSWORD=".*?"', 'PASSWORD="********"', message)
@@ -319,7 +336,7 @@ def _upload_file(self, filename, progress):
         try:
             while True:
                 d = sock.read()
-                data += d.decode('latin-1')
+                data += d.decode('ascii')
                 if not d:
                     break
         except socket.sslerror: # Connection closed
@@ -454,7 +471,7 @@ def _communicate(self, xml, protocol, progress=None, save=True):
         data = ''
         try:
             while True:
-                d = sock.read().decode('latin-1')
+                d = sock.read().decode('ascii', 'iloxml_replace')
                 data += d
                 if not d:
                     break
@@ -1889,7 +1906,7 @@ def xmldata(self, item='all'):
                 opener = urllib2.build_opener(urllib2.ProxyHandler({}))
             req = opener.open(url, None, self.timeout)
             data = req.read()
-            self._debug(1, str(req.headers).rstrip() + "\n\n" + data.decode('utf-8', 'replace'))
+            self._debug(1, str(req.headers).rstrip() + "\n\n" + data.decode('ascii', 'iloxml_replace'))
         if self.save_response:
             fd = open(self.save_response, 'a')
             fd.write(data)