histedit: use base for computing renames when folding (issue3729) When a file was renamed in the very first changeset being histedited, the rename was not detected. Consider a history like this: 0 base: add a.txt 1 first: rename a.txt to b.txt 2 last: edit b.txt When 1 and 2 are edited, copies.pathcopies(first, last) correctly returns that nothing was renamed. We must instead use copies.pathcopies(first, last) to detect the initial rename.