On Tue, Jun 29, 2021 at 5:50 AM Derrick Stolee <stolee@xxxxxxxxx> wrote:
>
> On 6/26/2021 1:05 PM, Elijah Newren via GitGitGadget wrote:
> > From: Elijah Newren <newren@xxxxxxxxx>
> >
> > Directory rename detection can cause transitive renames, e.g. if the two
> > different sides of history each do one half of:
> > A/file -> B/file
> > B/ -> C/
> > then directory rename detection transitively renames to give us C/file.
> > Since the default for merge.directoryRenames is conflict, this results
> > in an error message saying it is unclear whether the file should be
> > placed at B/file or C/file.
> >
> > What if C/ is A/, though?
>
> This case seems interesting, but somehow missing from the test cases
> below. Each of those cases include renaming up or down the directory
> hierarchy instead of doing a sideways rename.
>
> > +# Testcase 12i, Directory rename causes rename-to-self
> > +# Commit O: source/{subdir/foo, bar, baz_1}
> > +# Commit A: source/{foo, bar, baz_1}
> > +# Commit B: source/{subdir/{foo, bar}, baz_2}
> > +# Expected: source/{foo, bar, baz_2}, with conflicts on
> > +# source/bar vs. source/subdir/bar
>
> This test goes deeper.
>
> > +# Testcase 12j, Directory rename to root causes rename-to-self
> > +# Commit O: {subdir/foo, bar, baz_1}
> > +# Commit A: {foo, bar, baz_1}
> > +# Commit B: {subdir/{foo, bar}, baz_2}
> > +# Expected: {foo, bar, baz_2}, with conflicts on bar vs. subdir/bar
>
> This test goes higher.
>
> Does the problematic case not hit when going out to the side, such
> as "with conflicts on subdir/bar vs otherdir/bar"?
>
> If so, then _maybe_ the commit message could indicate this is an
> omission on purpose. If not, then maybe a third test should be
> added?
The only special case in the code is renaming to the root directory,
so I didn't think of extending beyond two cases. However, while
adding more testcases doesn't exercise the current incarnation of the
code further, it's pretty easy to add another and it certainly doesn't
hurt. I'll resubmit with a third testcase.
