# HG changeset patch
# User Denis Laxalde <denis.laxalde@logilab.fr>
# Date 1571920284 -7200
# Node ID 866bd2cf764b58f706e91c117b11e6ffb3ff8cbb
# Parent  84c15836a2d72f5d3f81eab15361b9d371088f63
mail: catch LookupError in headdecode()

We already catch this exception in _encode() (called by headencode()).
It gets raised when running test-notify.t with Python 3.

diff -r 84c15836a2d7 -r 866bd2cf764b mercurial/mail.py
--- a/mercurial/mail.py	Thu Oct 24 16:56:36 2019 +0200
+++ b/mercurial/mail.py	Thu Oct 24 14:31:24 2019 +0200
@@ -458,7 +458,7 @@
             try:
                 uparts.append(part.decode(charset))
                 continue
-            except UnicodeDecodeError:
+            except (UnicodeDecodeError, LookupError):
                 pass
         # On Python 3, decode_header() may return either bytes or unicode
         # depending on whether the header has =?<charset>? or not