leoPy.leo contains the following script. I have just renamed it to "script: diff-branches/revs (one file)":
import leo.commands.editFileCommands as efc
efc.GitDiffController(c).diff_two_branches(
branch1='bc24e607a5', # old branch/rev
branch2='devel', # new branch/rev
fn='leo/plugins/free_layout.py',
directory=None,
)
Previously, I had assumed that only branch names could be used, but then I thought that git generally allows many kind of specifiers, as shown above. This is very convenient and is way, way,
way easier to understand than using gitk.