undo-files: cleanup legacy files when applicable
The "journal" code is much more compact in 6.4, and so is the "undo" files as a
result. However the previous version were much noisier, so let us cleanup undo
files from older version too.
# extension to emulate interrupting filemerge._filemerge
from mercurial import (
error,
extensions,
filemerge,
)
def failfilemerge(*args, **kwargs):
raise error.Abort(b"^C")
def extsetup(ui):
extensions.wrapfunction(filemerge, 'filemerge', failfilemerge)