L10N contributors using mercurial tools have to compare source tree files with their locale files. Then copy any missing strings as reported by compare-locale before translating. This process is captured in this screencast: http://aalam.fedorapeople.org/firefox_translation/firefox_translation_with_hg.webm Few possible solutions: It would good to automate this process on Mozilla Infrastructure. Perhaps someone could write a script that could compares two repo and do a merge. This is would be the best, as L10N contributors would only need to do 'hg update' and continue translations. A workaround would be to give tool/program that compares remote en-US locale and add missing strings to their local repo.

This isn't really "Mozilla Infrastructure". Editors can be extended to support string copies, or even just be helpful in doing this manually. If you, for example, install cloud9 locally to edit, and have both en-US and l10n in your workspace, you can rather easily open both en-US and l10n browser.dtd, and then copy over. Mass-copying over is evil, as it ends up modifying files with text content that the localizer didn't ever look at. Resolving INVALID as it's contradicting the tools vision. Aisle will do the right thing, btw, which is different from what this bug asks for, but addresses the underlying problem.