Hi, the attached patch adds two lines to ${FILESDIR}/50po-mode-gentoo.el which are taken from gettext manual and cause the encoding in which to save the buffer (the po file) to be guessed directly from a field which is mandatory in the po file and specifies the encoding. (without this, one has to specify the encoding manually before saving).
Created attachment 79470 [details, diff] gettext po-mode site-gentoo.el patch I forgot to mention specifically that this relates to sys-devel/gettext.
Thanks for the bug report. I applied the improvement to portage CVS.