rebase: write series file without removed mq patches Rebase will remove empty changesets and will also completely remove the mq patch file for rebased empty patches. Starting with b28004513977 (1.9) it would preserve guards by writing the old series file back. That would however also reintroduce removed patch files in the series file and the inconsistency would make qpop + qpush fail. This patch backs out most of b28004513977 and makes sure guards are preserved without reintroducing removed patches.