During an interactive rebase, Git sometimes opens your editor to amend a commit message (e.g. after resolving a merge conflict). Unfortunately, as rerebase has overridden your editor, it takes over and strips newlines after you've written your nice commit message. I would think it also tries to insert diffs into your commit message, but thankfully this fails. This can be easily worked around by just never resuming a rebase with rerebase in effect, but this is a bit hacky. The obvious solution here is to mimic Git more faithfully and only strip comments, not blank lines as well.
During an interactive rebase, Git sometimes opens your editor to amend a commit message (e.g. after resolving a merge conflict). Unfortunately, as rerebase has overridden your editor, it takes over and strips newlines after you've written your nice commit message. I would think it also tries to insert diffs into your commit message, but thankfully this fails. This can be easily worked around by just never resuming a rebase with rerebase in effect, but this is a bit hacky. The obvious solution here is to mimic Git more faithfully and only strip comments, not blank lines as well.