--- a/mercurial/pure/base85.py	Mon Sep 30 19:40:14 2024 -0400
+++ b/mercurial/pure/base85.py	Fri Oct 04 23:09:56 2024 -0400
@@ -58,6 +58,8 @@
 
     l = len(text)
     out = []
+    acc = 0
+
     for i in range(0, len(text), 5):
         chunk = text[i : i + 5]
         chunk = pycompat.bytestr(chunk)