update-po: Keep POT's order of translations

[Blipz]

It would be nice (if not the default, as an option) to keep translations in the order they appear in the POT file when executing the update-po command.

This would help translators better understand the context (keep messages close to one another if they originate from the same source file) and make the diffs clearer (for instance, when a source message is changed in the code).

[swissspidy]

Interesting suggestion!

Not sure if the underlying library we use actually supports this. It would require some investigation.

[Blipz]

I think it does. The basic idea would be to replace:

$po_translations->mergeWith(
    $pot_translations,
    Merge::ADD | Merge::REMOVE | Merge::COMMENTS_THEIRS | Merge::EXTRACTED_COMMENTS_THEIRS | Merge::REFERENCES_THEIRS | Merge::DOMAIN_OVERRIDE
);

by something like:

$pot_translations->mergeWith(
    $po_translations,
    Merge::COMMENTS_OURS | Merge::EXTRACTED_COMMENTS_OURS | Merge::REFERENCES_OURS  // not sure about all the flags to pass there
);