diff -r 57875cf423c9 -r 2372284d9457 mercurial/revlogutils/sidedata.py
--- a/mercurial/revlogutils/sidedata.py	Sat Oct 05 10:29:34 2019 -0400
+++ b/mercurial/revlogutils/sidedata.py	Sun Oct 06 09:45:02 2019 -0400
@@ -52,6 +52,7 @@
 SIDEDATA_HEADER = struct.Struct(r'>H')
 SIDEDATA_ENTRY = struct.Struct(r'>HL20s')
 
+
 def sidedatawriteprocessor(rl, text, sidedata):
     sidedata = list(sidedata.items())
     sidedata.sort()
@@ -64,10 +65,11 @@
     rawtext.append(bytes(text))
     return ''.join(rawtext), False
 
+
 def sidedatareadprocessor(rl, text):
     sidedata = {}
     offset = 0
-    nbentry, = SIDEDATA_HEADER.unpack(text[:SIDEDATA_HEADER.size])
+    (nbentry,) = SIDEDATA_HEADER.unpack(text[: SIDEDATA_HEADER.size])
     offset += SIDEDATA_HEADER.size
     dataoffset = SIDEDATA_HEADER.size + (SIDEDATA_ENTRY.size * nbentry)
     for i in range(nbentry):
@@ -85,10 +87,12 @@
     text = text[dataoffset:]
     return text, True, sidedata
 
+
 def sidedatarawprocessor(rl, text):
     # side data modifies rawtext and prevent rawtext hash validation
     return False
 
+
 processors = (
     sidedatareadprocessor,
     sidedatawriteprocessor,