--- a/mercurial/pure/base85.py	Sat Oct 05 10:29:34 2019 -0400
+++ b/mercurial/pure/base85.py	Sun Oct 06 09:45:02 2019 -0400
@@ -11,15 +11,19 @@
 
 from .. import pycompat
 
-_b85chars = pycompat.bytestr("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef"
-                             "ghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~")
+_b85chars = pycompat.bytestr(
+    "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef"
+    "ghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"
+)
 _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
 _b85dec = {}
 
+
 def _mkb85dec():
     for i, c in enumerate(_b85chars):
         _b85dec[c] = i
 
+
 def b85encode(text, pad=False):
     """encode text in base85 format"""
     l = len(text)
@@ -27,12 +31,14 @@
     if r:
         text += '\0' * (4 - r)
     longs = len(text) >> 2
-    words = struct.unpack('>%dL' % (longs), text)
+    words = struct.unpack('>%dL' % longs, text)
 
-    out = ''.join(_b85chars[(word // 52200625) % 85] +
-                  _b85chars2[(word // 7225) % 7225] +
-                  _b85chars2[word % 7225]
-                  for word in words)
+    out = ''.join(
+        _b85chars[(word // 52200625) % 85]
+        + _b85chars2[(word // 7225) % 7225]
+        + _b85chars2[word % 7225]
+        for word in words
+    )
 
     if pad:
         return out
@@ -44,6 +50,7 @@
     olen += l // 4 * 5
     return out[:olen]
 
+
 def b85decode(text):
     """decode base85-encoded text"""
     if not _b85dec:
@@ -52,15 +59,16 @@
     l = len(text)
     out = []
     for i in range(0, len(text), 5):
-        chunk = text[i:i + 5]
+        chunk = text[i : i + 5]
         chunk = pycompat.bytestr(chunk)
         acc = 0
         for j, c in enumerate(chunk):
             try:
                 acc = acc * 85 + _b85dec[c]
             except KeyError:
-                raise ValueError('bad base85 character at position %d'
-                                 % (i + j))
+                raise ValueError(
+                    'bad base85 character at position %d' % (i + j)
+                )
         if acc > 4294967295:
             raise ValueError('Base85 overflow in hunk starting at byte %d' % i)
         out.append(acc)
@@ -70,11 +78,11 @@
     if cl:
         acc *= 85 ** (5 - cl)
         if cl > 1:
-            acc += 0xffffff >> (cl - 2) * 8
+            acc += 0xFFFFFF >> (cl - 2) * 8
         out[-1] = acc
 
     out = struct.pack('>%dL' % (len(out)), *out)
     if cl:
-        out = out[:-(5 - cl)]
+        out = out[: -(5 - cl)]
 
     return out