--- a/hgext/evolve.py	Mon Sep 10 18:56:44 2012 +0200
+++ b/hgext/evolve.py	Tue Sep 11 11:45:00 2012 +0200
@@ -1232,15 +1232,18 @@
         cmdutil.duplicatecopies(repo, orig.node(), dest.node())
         nodesrc = orig.node()
         destphase = repo[nodesrc].phase()
-        if rebase.rebasenode.func_code.co_argcount == 5:
-            # rebasenode collapse argument was introduced by
-            # d1afbf03e69a (2.3)
-            rebase.rebasenode(repo, orig.node(), dest.node(),
-                              {node.nullrev: node.nullrev}, False)
-        else:
-            rebase.rebasenode(repo, orig.node(), dest.node(),
-                              {node.nullrev: node.nullrev})
         try:
+            if rebase.rebasenode.func_code.co_argcount == 5:
+                # rebasenode collapse argument was introduced by
+                # d1afbf03e69a (2.3)
+                r = rebase.rebasenode(repo, orig.node(), dest.node(),
+                                      {node.nullrev: node.nullrev}, False)
+            else:
+                r = rebase.rebasenode(repo, orig.node(), dest.node(),
+                                     {node.nullrev: node.nullrev})
+            if r[-1]: #some conflict
+                raise util.Abort(
+                        'unresolved merge conflicts (see hg help resolve)')
             nodenew = rebase.concludenode(repo, orig.node(), dest.node(),
                                           node.nullid)
         except util.Abort, exc:

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-stabilize-conflict.t	Tue Sep 11 11:45:00 2012 +0200
@@ -0,0 +1,250 @@
+=================================================================
+This files test the proper behavior of evo during merge conflict.
+=================================================================
+
+Initial setup
+
+  $ cat >> $HGRCPATH <<EOF
+  > [ui]
+  > interactive=false
+  > merge=internal:merge
+  > [defaults]
+  > amend=-d "0 0"
+  > [merge-tools]
+  > touch.checkchanged=true
+  > touch.gui=true
+  > touch.args=babar
+  > [extensions]
+  > hgext.rebase=
+  > EOF
+  $ echo "evolve=$(echo $(dirname $TESTDIR))/hgext/evolve.py" >> $HGRCPATH
+
+
+create a simple repo
+
+  $ hg init repo
+  $ cd repo
+  $ cat << EOF > babar
+  > un
+  > deux
+  > trois
+  > quatre
+  > cinq
+  > EOF
+  $ hg add babar
+  $ hg commit -m "babar count up to five"
+  $ cat << EOF >> babar
+  > six
+  > sept
+  > huit
+  > neuf
+  > dix
+  > EOF
+  $ hg commit -m "babar count up to ten"
+  $ cat << EOF >> babar
+  > onze
+  > douze
+  > treize
+  > quatorze
+  > quinze
+  > EOF
+  $ hg commit -m "babar count up to fifteen"
+
+
+proper behavior without conflict
+----------------------------------
+
+  $ hg gdown
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  [1] babar count up to ten
+  $ sed -i'' 's/huit/height/' babar
+  $ hg diff
+  diff -r 9d5daf8bd956 babar
+  --- a/babar	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/babar	* (glob)
+  @@ -5,6 +5,6 @@
+   cinq
+   six
+   sept
+  -huit
+  +height
+   neuf
+   dix
+  $ hg amend
+  1 new unstable changesets
+  $ hg evolve
+  move:[2] babar count up to fifteen
+  atop:[4] babar count up to ten
+  merging babar
+  $ hg resolve -l
+  $ hg log -G
+  @  changeset:   5:fd62611d0178
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to fifteen
+  |
+  o  changeset:   4:83066dedff55
+  |  parent:      0:29ec1554cfaf
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to ten
+  |
+  o  changeset:   0:29ec1554cfaf
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     babar count up to five
+  
+
+
+proper behavior with conflict using internal:merge
+--------------------------------------------------
+
+  $ hg gdown
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  [4] babar count up to ten
+  $ sed -i'' 's/dix/ten/' babar
+  $ hg diff
+  diff -r 83066dedff55 babar
+  --- a/babar	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/babar	* (glob)
+  @@ -7,4 +7,4 @@
+   sept
+   height
+   neuf
+  -dix
+  +ten
+  $ hg amend
+  1 new unstable changesets
+  $ hg evolve
+  move:[5] babar count up to fifteen
+  atop:[7] babar count up to ten
+  merging babar
+  warning: conflicts during merge.
+  merging babar incomplete! (edit conflicts, then use 'hg resolve --mark')
+  evolve failed!
+  fix conflict and run "hg evolve --continue"
+  abort: unresolved merge conflicts (see hg help resolve)
+  [255]
+  $ hg resolve -l
+  U babar
+  $ hg log -G
+  @  changeset:   7:cc96f75eae0b
+  |  tag:         tip
+  |  parent:      0:29ec1554cfaf
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to ten
+  |
+  | @  changeset:   5:fd62611d0178
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     babar count up to fifteen
+  | |
+  | x  changeset:   4:83066dedff55
+  |/   parent:      0:29ec1554cfaf
+  |    user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     babar count up to ten
+  |
+  o  changeset:   0:29ec1554cfaf
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     babar count up to five
+  
+(fix the conflict and continue)
+
+  $ hg revert -r 5 --all
+  reverting babar
+  $ sed -i'' 's/dix/ten/' babar
+  $ hg resolve --all -m
+  $ hg evolve --continue
+  grafting revision 5
+  $ hg resolve -l
+  $ hg log -G
+  @  changeset:   8:ce7ee8fecf30
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to fifteen
+  |
+  o  changeset:   7:cc96f75eae0b
+  |  parent:      0:29ec1554cfaf
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to ten
+  |
+  o  changeset:   0:29ec1554cfaf
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     babar count up to five
+  
+proper behavior with conflict using an external merge tools
+-----------------------------------------------------------
+
+  $ sed -i'' 's/merge=.*/merge=touch/' $HGRCPATH
+  $ sed -i'' 's/touch.gui=.*/touch.gui=false/' $HGRCPATH
+  $ hg gdown
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  [7] babar count up to ten
+  $ sed -i'' 's/ten/zehn/' babar
+  $ hg diff
+  diff -r cc96f75eae0b babar
+  --- a/babar	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/babar	* (glob)
+  @@ -7,4 +7,4 @@
+   sept
+   height
+   neuf
+  -ten
+  +zehn
+  $ hg amend
+  1 new unstable changesets
+  $ sed -i'' 's/interactive=.*/interactive=true/' $HGRCPATH
+  $ yes n 2> ../shutup | HGMERGE=touch hg evolve
+  move:[8] babar count up to fifteen
+  atop:[10] babar count up to ten
+  merging babar
+   output file babar appears unchanged
+  was merge successful (yn)? merging babar failed!
+  evolve failed!
+  fix conflict and run "hg evolve --continue"
+  abort: unresolved merge conflicts (see hg help resolve)
+  [255]
+  $ hg resolve -l
+  U babar
+  $ hg log -G
+  @  changeset:   10:02c637e61375
+  |  tag:         tip
+  |  parent:      0:29ec1554cfaf
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     babar count up to ten
+  |
+  | @  changeset:   8:ce7ee8fecf30
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     babar count up to fifteen
+  | |
+  | x  changeset:   7:cc96f75eae0b
+  |/   parent:      0:29ec1554cfaf
+  |    user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     babar count up to ten
+  |
+  o  changeset:   0:29ec1554cfaf
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     babar count up to five
+  
+  $ cat babar
+  un
+  deux
+  trois
+  quatre
+  cinq
+  six
+  sept
+  height
+  neuf
+  zehn