store: slice over a bytestring to get characters instead of ascii values

On Python 2,

>>> a = b'abc'
>>> a[1]
'b'

Whereas on python 3,

>>> a = b'abc'
>>> a[1]
98
>>> a[1:2]
b'b'

This does not change behaviour on python 2.

mercurial/store.py

@@ -101,7 +101,7 b' def _buildencodefun():'
     e = '_'
     if pycompat.ispy3:
         xchr = lambda x: bytes([x])
-        asciistr = [bytes(a) for a in range(127)]
+        asciistr = [bytes([a]) for a in range(127)]
     else:
         xchr = chr
         asciistr = map(chr, xrange(127))
@@ -128,7 +128,7 b' def _buildencodefun():'
                     pass
             else:
                 raise KeyError
-    return (lambda s: ''.join([cmap[c] for c in s]),
+    return (lambda s: ''.join([cmap[s[c:c + 1]] for c in xrange(len(s))]),
             lambda s: ''.join(list(decode(s))))
 
 _encodefname, _decodefname = _buildencodefun()