rebase: clear merge state when aborting in-memory merge on dirty working copy

Differential Revision: https://phab.mercurial-scm.org/D9509

hgext/rebase.py

@@ -638,7 +638,12 b' class rebaseruntime(object):'
                                 b"commit again in the working copy\n"
                             )
                         )
-                        cmdutil.bailifchanged(repo)
+                        try:
+                            cmdutil.bailifchanged(repo)
+                        except error.Abort:
+                            clearstatus(repo)
+                            clearcollapsemsg(repo)
+                            raise
                         self.inmemory = False
                         self._assignworkingcopy()
                         mergemod.update(repo[p1], wc=self.wctx)

tests/test-rebase-inmemory.t

@@ -489,12 +489,6 b" Retrying without in-memory merge won't l"
   dirty
   $ hg status -v
   M a
-  # The repository is in an unfinished *rebase* state.
-  
-  # To continue:    hg rebase --continue
-  # To abort:       hg rebase --abort
-  # To stop:        hg rebase --stop
-  
 
 Retrying without in-memory merge won't lose merge state
   $ cd ..