extdiff: prevent exception on double-translation
The docstring is translated twice: once when used as a format string,
and once on display. The second translation fails when the first
translation introduces non-ASCII characters in the string.
The problem is that the gettext module calls unicode(message) on the
string, i.e., it decodes it to a Unicode string using the ASCII
encoding (the default encoding). By translating it into a Unicode
string here, the unicode() call becomes a noop.
% basic
% unknown
alias 'unknown' resolves to unknown command 'bargle'
% ambiguous
alias 'ambiguous' resolves to ambiguous command 's'
% recursive
alias 'recursive' resolves to unknown command 'recursive'
% no definition
no definition for alias 'nodefinition'
adding foo
% with opts
C foo
% with opts and whitespace
0 e63c23eaa88a | 1970-01-01 00:00 +0000
% interaction with defaults
0:e63c23eaa88a
-1:000000000000
% properly recursive
changeset: -1:0000000000000000000000000000000000000000
parent: -1:0000000000000000000000000000000000000000
parent: -1:0000000000000000000000000000000000000000
manifest: -1:0000000000000000000000000000000000000000
user:
date: Thu Jan 01 00:00:00 1970 +0000
extra: branch=default