# HG changeset patch
# User Augie Fackler <augie@google.com>
# Date 2018-02-18 19:37:36
# Node ID 3f98634b65729482cbee4275f0137b7727aeddda
# Parent  3ac8b5c1c36c8b35c62ea594abc216d8870d63f5

scmutil: fix requires-file isalnum() check on first byte

Slice instead of subscript to get a bytes from a bytes.

# skip-blame just a py3 slice-instead-of-subscript change

Differential Revision: https://phab.mercurial-scm.org/D2341

diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -887,7 +887,7 @@ def readrequires(opener, supported):
     missings = []
     for r in requirements:
         if r not in supported:
-            if not r or not r[0].isalnum():
+            if not r or not r[0:1].isalnum():
                 raise error.RequirementError(_(".hg/requires file is corrupt"))
             missings.append(r)
     missings.sort()