--- a/hgext/evolve.py	Tue Jun 16 10:19:17 2015 -0700
+++ b/hgext/evolve.py	Tue Jun 16 14:30:43 2015 -0700
@@ -1234,12 +1234,12 @@
         ui.status(_('working directory is now at %s\n') % repo['.'])
 
 def _singlesuccessor(repo, p):
-    """returns p if not obsolete or its unique latest successors
+    """returns p (as rev) if not obsolete or its unique latest successors
 
     fail if there are no such successor"""
 
     if not p.obsolete():
-        return p
+        return p.rev()
     obs = repo[p]
     ui = repo.ui
     newer = obsolete.successorssets(repo, obs.node())

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-evolve-order.t	Tue Jun 16 14:30:43 2015 -0700
@@ -0,0 +1,129 @@
+evolve --rev reordering
+-----------------------
+
+  $ cat >> $HGRCPATH <<EOF
+  > [defaults]
+  > amend=-d "0 0"
+  > fold=-d "0 0"
+  > [web]
+  > push_ssl = false
+  > allow_push = *
+  > [phases]
+  > publish = False
+  > [diff]
+  > git = 1
+  > unified = 0
+  > [ui]
+  > logtemplate = {rev}:{node|short}@{branch}({phase}) {desc|firstline}\n
+  > [extensions]
+  > hgext.graphlog=
+  > EOF
+  $ echo "evolve=$(echo $(dirname $TESTDIR))/hgext/evolve.py" >> $HGRCPATH
+  $ mkcommit() {
+  >    echo "$1" > "$1"
+  >    hg add "$1"
+  >    hg ci -m "add $1"
+  > }
+
+  $ mkstack() {
+  >    # Creates a stack of commit based on $1 with messages from $2, $3 ..
+  >    hg update $1 -C
+  >    shift
+  >    mkcommits $*
+  > }
+
+  $ shaof() {
+  >   hg log -T {node} -r "first(desc($1))"
+  > }
+
+  $ mkcommits() {
+  >   for i in $@; do mkcommit $i ; done
+  > }
+
+Initial setup
+  $ hg init testrevorder
+  $ cd testrevorder
+  $ mkcommits p _a _b _c
+  $ hg phase --public 0
+  $ hg up 'desc(_a)'
+  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  $ echo "aaa" > _a
+  $ hg amend
+  2 new unstable changesets
+  $ hg log -G
+  @  5:12d519679175@default(draft) add _a
+  |
+  | o  3:4d156641b718@default(draft) add _c
+  | |
+  | o  2:4d7242ebb004@default(draft) add _b
+  | |
+  | x  1:2d73fcd7f07d@default(draft) add _a
+  |/
+  o  0:f92638be10c7@default(public) add p
+  
+
+evolve --rev reorders the rev to solve instability, trivial case 2 revs wrong order
+  $ hg evolve --rev 'desc(_c) + desc(_b)'
+  move:[2] add _b
+  atop:[5] add _a
+  move:[3] add _c
+  atop:[6] add _b
+  working directory is now at 52b8f9b04f83
+
+evolve --rev reorders the rev to solve instability. Harder case, obsolescence
+accross three stacks in growing rev numbers.
+  $ hg up "desc(_c)"
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ mkcommit d
+  $ hg up "desc(_a)"
+  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
+  $ hg amend -m "aprime"
+  3 new unstable changesets
+  $ hg evolve --rev "desc(_b)"
+  move:[6] add _b
+  atop:[9] aprime
+  working directory is now at 476c9c052aae
+  $ hg up "desc(_b) - obsolete()"
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg amend -m "bprime"
+  $ hg up "desc(aprime)"
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg amend -m "asecond"
+  1 new unstable changesets
+  $ hg log -G
+  @  12:9a584314f3f3@default(draft) asecond
+  |
+  | o  11:a59c79776f7c@default(draft) bprime
+  | |
+  | x  9:81a687b96d4d@default(draft) aprime
+  |/
+  | o  8:2d86cc7ec3a9@default(draft) add d
+  | |
+  | o  7:52b8f9b04f83@default(draft) add _c
+  | |
+  | x  6:59476c3836ef@default(draft) add _b
+  | |
+  | x  5:12d519679175@default(draft) add _a
+  |/
+  o  0:f92638be10c7@default(public) add p
+  
+  $ hg evolve --rev "unstable()"
+  move:[11] bprime
+  atop:[12] asecond
+  move:[7] add _c
+  atop:[13] bprime
+  move:[8] add d
+  atop:[14] add _c
+  working directory is now at fd447ba1b20b
+  $ hg log -G
+  @  15:fd447ba1b20b@default(draft) add d
+  |
+  o  14:0fc229278e4d@default(draft) add _c
+  |
+  o  13:c3741b9eafae@default(draft) bprime
+  |
+  o  12:9a584314f3f3@default(draft) asecond
+  |
+  o  0:f92638be10c7@default(public) add p
+  
+