# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 2015-05-14 21:28:28
# Node ID d1bd0fd07ee6adf4ab3be2b0a0a7c0df54d55abf
# Parent  0021ad4c2309e1451f327ec544c525cb1e419584
# Parent  bd98d073a34fcf9651a77a9265878db1f7c88044

merge with stable

diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -839,16 +839,21 @@ def restorestatus(repo):
             raise
         raise util.Abort(_('no rebase in progress'))
 
-def inrebase(repo, originalwd, state):
-    '''check whether the working dir is in an interrupted rebase'''
+def needupdate(repo, state):
+    '''check whether we should `update --clean` away from a merge, or if
+    somehow the working dir got forcibly updated, e.g. by older hg'''
     parents = [p.rev() for p in repo.parents()]
-    if originalwd in parents:
+
+    # Are we in a merge state at all?
+    if len(parents) < 2:
+        return False
+
+    # We should be standing on the first as-of-yet unrebased commit.
+    firstunrebased = min([old for old, new in state.iteritems()
+                          if new == nullrev])
+    if firstunrebased in parents:
         return True
 
-    for newrev in state.itervalues():
-        if newrev in parents:
-            return True
-
     return False
 
 def abort(repo, originalwd, target, state, activebookmark=None):
@@ -875,7 +880,7 @@ def abort(repo, originalwd, target, stat
 
     if cleanup:
         # Update away from the rebase if necessary
-        if inrebase(repo, originalwd, state):
+        if needupdate(repo, state):
             merge.update(repo, originalwd, False, True, False)
 
         # Strip from the first rebased revision
diff --git a/tests/test-rebase-abort.t b/tests/test-rebase-abort.t
--- a/tests/test-rebase-abort.t
+++ b/tests/test-rebase-abort.t
@@ -241,3 +241,83 @@ rebase abort should not leave working co
   o  0 a
   
   $ cd ..
+
+Make sure we don't clobber changes in the working directory when the
+user has somehow managed to update to a different revision (issue4009)
+
+  $ hg init noupdate
+  $ cd noupdate
+  $ hg book @
+  $ echo original > a
+  $ hg add a
+  $ hg commit -m a
+  $ echo x > b
+  $ hg add b
+  $ hg commit -m b1
+  $ hg up 0
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  (leaving bookmark @)
+  $ hg book foo
+  $ echo y > b
+  $ hg add b
+  $ hg commit -m b2
+  created new head
+
+  $ hg rebase -d @ -b foo --tool=internal:fail
+  rebasing 2:070cf4580bb5 "b2" (tip foo)
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+
+  $ mv .hg/rebasestate ./ # so we're allowed to hg up like in mercurial <2.6.3
+  $ hg up -C 0            # user does other stuff in the repo
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+
+  $ mv rebasestate .hg/   # user upgrades to 2.7
+
+  $ echo new > a
+  $ hg up 1               # user gets an error saying to run hg rebase --abort
+  abort: rebase in progress
+  (use 'hg rebase --continue' or 'hg rebase --abort')
+  [255]
+
+  $ cat a
+  new
+  $ hg rebase --abort
+  rebase aborted
+  $ cat a
+  new
+
+  $ cd ..
+
+On the other hand, make sure we *do* clobber changes whenever we
+haven't somehow managed to update the repo to a different revision
+during a rebase (issue4661)
+
+  $ hg ini yesupdate
+  $ cd yesupdate
+  $ echo "initial data" > foo.txt
+  $ hg add
+  adding foo.txt
+  $ hg ci -m "initial checkin"
+  $ echo "change 1" > foo.txt
+  $ hg ci -m "change 1"
+  $ hg up 0
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ echo "conflicting change 1" > foo.txt
+  $ hg ci -m "conflicting 1"
+  created new head
+  $ echo "conflicting change 2" > foo.txt
+  $ hg ci -m "conflicting 2"
+
+  $ hg rebase -d 1 --tool 'internal:fail'
+  rebasing 2:e4ea5cdc9789 "conflicting 1"
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --abort
+  rebase aborted
+  $ hg summary
+  parent: 3:b16646383533 tip
+   conflicting 2
+  branch: default
+  commit: (clean)
+  update: 1 new changesets, 2 branch heads (merge)