t6423: rename file within directory that other side renamed

Add a new testcase where one side of history renames:
   olddir/ -> newdir/
and the other side of history renames:
   olddir/a -> olddir/alpha

When using merge.directoryRenames=true, it seems logical to expect the
file to end up at newdir/alpha.  Unfortunately, both merge-recursive and
merge-ort currently see this as a rename/rename conflict:

   olddir/a -> newdir/a
vs.
   olddir/a -> newdir/alpha

Suggesting that there's some extra logic we probably want to add
somewhere to allow this case to run without triggering a conflict.  For
now simply document this known issue.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t6423-merge-rename-directories.sh b/t/t6423-merge-rename-directories.sh
index 4c3d0b95dc5c6f6f73a709e7a92aa0db10f072cd..3037c5c9bf479fdb27168b76c8538beb1135c715 100755 (executable)
--- a/t/t6423-merge-rename-directories.sh
+++ b/t/t6423-merge-rename-directories.sh
@@ -4966,6 +4966,64 @@ test_expect_success '12g: Testcase with two kinds of "relevant" renames' '
        )
 '
 
+# Testcase 12h, Testcase with two kinds of "relevant" renames
+#   Commit O: olddir/{a_1, b}
+#   Commit A: newdir/{a_2, b}
+#   Commit B: olddir/{alpha_1, b}
+#   Expected: newdir/{alpha_2, b}
+
+test_setup_12h () {
+       test_create_repo 12h &&
+       (
+               cd 12h &&
+
+               mkdir olddir &&
+               test_seq 3 8 >olddir/a &&
+               >olddir/b &&
+               git add olddir &&
+               git commit -m orig &&
+
+               git branch O &&
+               git branch A &&
+               git branch B &&
+
+               git switch A &&
+               test_seq 3 10 >olddir/a &&
+               git add olddir/a &&
+               git mv olddir newdir &&
+               git commit -m A &&
+
+               git switch B &&
+
+               git mv olddir/a olddir/alpha &&
+               git commit -m B
+       )
+}
+
+test_expect_failure '12h: renaming a file within a renamed directory' '
+       test_setup_12h &&
+       (
+               cd 12h &&
+
+               git checkout A^0 &&
+
+               test_might_fail git -c merge.directoryRenames=true merge -s recursive B^0 &&
+
+               git ls-files >tracked &&
+               test_line_count = 2 tracked &&
+
+               test_path_is_missing olddir/a &&
+               test_path_is_file newdir/alpha &&
+               test_path_is_file newdir/b &&
+
+               git rev-parse >actual \
+                       HEAD:newdir/alpha  HEAD:newdir/b &&
+               git rev-parse >expect \
+                       A:newdir/a         O:oldir/b &&
+               test_cmp expect actual
+       )
+'
+
 ###########################################################################
 # SECTION 13: Checking informational and conflict messages
 #