Merge branch 'pw/rebase-skip-final-fix' into maint

Checking out all the paths from HEAD during the last conflicted step in "git rebase" and continuing would cause the step to be skipped (which is expected), but leaves MERGE_MSG file behind in $GIT_DIR and confuses the next "git commit", which has been corrected. * pw/rebase-skip-final-fix: rebase --continue: remove .git/MERGE_MSG rebase --apply: restore some tests t3403: fix commit authorship