diff -r b54524ae77c0 -r 0b714c4ad9ff tests/test-stabilize-order.t
--- a/tests/test-stabilize-order.t	Tue Jun 23 13:20:00 2015 -0700
+++ b/tests/test-stabilize-order.t	Mon Jun 22 19:24:21 2015 -0700
@@ -182,3 +182,66 @@
   $ hg evolve --any -v
   no unstable changesets to evolve
   [1]
+
+Ambiguous evolution
+  $ echo a > k
+  $ hg add k
+  $ hg ci -m firstambiguous
+  $ hg up .^
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ echo a > l
+  $ hg add l
+  $ hg ci -m secondambiguous
+  created new head
+  $ hg up .^
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg commit --amend -m "newmessage"
+  2 new unstable changesets
+  $ hg log -G
+  @  changeset:   15:49773ccde390
+  |  tag:         tip
+  |  parent:      11:036cf654e942
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     newmessage
+  |
+  | o  changeset:   14:a9892777b519
+  | |  parent:      12:e99ecf51c867
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     secondambiguous
+  | |
+  | | o  changeset:   13:0b6e26b2472d
+  | |/   user:        test
+  | |    date:        Thu Jan 01 00:00:00 1970 +0000
+  | |    summary:     firstambiguous
+  | |
+  | x  changeset:   12:e99ecf51c867
+  |/   user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     addc
+  |
+  o  changeset:   11:036cf654e942
+  |  parent:      7:005fe5914f78
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     addb
+  |
+  o  changeset:   7:005fe5914f78
+  |  parent:      0:c471ef929e6a
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     adda
+  |
+  o  changeset:   0:c471ef929e6a
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     addroot
+  
+  $ hg evolve
+  abort: multiple evolve candidates
+  (select one of *, * with --rev) (glob)
+  [255]
+
+
+