The .in.in file was added to the repo in 8bdfa6a4e56f. Then Gary added the .in file to POTFILES.in in 1d98555... but I think it should actually be the .in.in file, right?
/* Getopt for GNU.
NOTE: getopt is now part of the C library, so if you don't know what
"Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
before changing it!
Pidgin is the legal property of its developers, whose names are too numerous
to list here. Please refer to the COPYRIGHT file distributed with this
source distribution.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* NOTE!!! AIX requires this to be the first thing in the file.