graft: add test for xdir graft of current commit

Summary: Add a failing test where the src and dst of the graft are the same commit. This should be allowed since the path mappings cause the src and dst to become different during the merge operation.

Reviewed By: sggutier

Differential Revision: D60027031

fbshipit-source-id: 6004b7dd90be08bc26967ae55597cc39b8ddf519

eden/scm/tests/test-graft-xdir.t

@@ -320,3 +320,26 @@ Can do multiple mappings in a single graft:
   @@ -1,1 +1,1 @@
   -A
   +AA
+
+
+Multiple mappings can all follow renames:
+  $ newclientrepo
+  $ drawdag <<EOS
+  > G  # G/dir/rename = AA\n
+  > |
+  > F  # F/dir/rename = A\n (renamed from dir/file)
+  > |
+  > E  # E/dir3/rename3 = A\n (renamed from dir3/file)
+  > |
+  > D  # D/dir3/file = A\n
+  > |
+  > C  # C/dir2/rename2 = A\n (renamed from dir2/file)
+  > |
+  > B  # B/dir2/file = A\n
+  > |
+  > A  # A/dir/file = A\n
+  > EOS
+  $ hg go -q $G
+  $ hg graft -qr $G --from-path dir --to-path dir2 --from-path dir --to-path dir3
+  skipping ancestor revision 301f396cc76c
+  [255]