Fix two crashes on slightly broken font files

The zeros at the end are not needed by our implementation so don't
crash if there are too few.

Always pass an even number of bytes to unhexlify.

lib/matplotlib/type1font.py

@@ -24,6 +24,7 @@
 import binascii
 import enum
 import itertools
+import logging
 import re
 import struct
 
@@ -32,6 +33,7 @@
 from matplotlib.cbook import _format_approx
 from . import _api
 
+_log = logging.getLogger(__name__)
 
 # token types
 _TokenType = enum.Enum('_TokenType',
@@ -129,13 +131,16 @@ def _split(self, data):
                 zeros -= 1
             idx -= 1
         if zeros:
-            raise RuntimeError('Insufficiently many zeros in Type 1 font')
+            # this may have been a problem on old implementations that
+            # used the zeros as necessary padding
+            _log.info('Insufficiently many zeros in Type 1 font')
 
         # Convert encrypted part to binary (if we read a pfb file, we may end
         # up converting binary to hexadecimal to binary again; but if we read
         # a pfa file, this part is already in hex, and I am not quite sure if
         # even the pfb format guarantees that it will be in binary).
-        binary = binascii.unhexlify(data[len1:idx+1])
+        idx1 = len1 + ((idx - len1 + 2) & ~1)  # ensure an even number of bytes
+        binary = binascii.unhexlify(data[len1:idx1])
 
         return data[:len1], binary, data[idx+1:]