How to merge po files

This page is created after the mail from Mişu Moldovan about merge issues (http://foo-projects.org/pipermail/xfce-i18n/2007-November/006292.html).

The idea is to keep the po directories in sync. Take the case where you update the stable branch, and you fix/correct sentences, then you want these to be corrected aswell in the trunk for later versions. The command line tool msgmerge does this job, and works as follows:

msgmerge the-most-recent-po the-po-to-sync > output.po

The result in output.po contains the-po-to-sync with the new translated strings from the-most-recent-po. You can check the diff between the-po-to-sync and output.po with a diff tool like meld or gvimdiff.

This gives you two possibilities:

You update the trunk, in that case you can merge against the branches (the stable branch in most cases)
You update a branch, in that case you merge against the trunk (and/or other branches…)

Example

As example, we say that xfce-mcs-manager/branches/xfce4_4/po/es.po has been updated, but trunk remains unchanged.

cd xfce-mcs-manager
msgmerge branches/xfce4_4/po/es.po trunk/po/es.po > trunk/po/es.po.new
meld trunk/po/es.po trunk/po/es.po.new
# Changes are OK
mv trunk/po/es.po.new trunk/po/es.po

Note: you can’t move the output from msgmerge directly over trunk/po/es.po because it will comment everything inside the output. Instead you can pipe the output to cat and redirect its output like:

msgmerge branches/xfce4_4/po/es.po trunk/po/es.po | cat > trunk/po/es.po