rebase: on abort, don't strip commits that didn't need rebased (issue5822)

I clearly missed adding this condition in 78496ac30025 (rebase: allow
rebase even if some revisions need no rebase (BC) (issue5422),
2017-05-11). Perhaps I should have opted for the "revdone" solution I
mentioned there...

Differential Revision: https://phab.mercurial-scm.org/D2879

hgext/rebase.py

@@ -1544,7 +1544,8 b' def abort(repo, originalwd, destmap, sta'
         # If the first commits in the rebased set get skipped during the rebase,
         # their values within the state mapping will be the dest rev id. The
         # rebased list must must not contain the dest rev (issue4896)
-        rebased = [s for r, s in state.items() if s >= 0 and s != destmap[r]]
+        rebased = [s for r, s in state.items()
+                   if s >= 0 and s != r and s != destmap[r]]
         immutable = [d for d in rebased if not repo[d].mutable()]
         cleanup = True
         if immutable:

tests/test-rebase-partial.t

@@ -87,13 +87,13 b" Abort doesn't lose the commits that were"
   unresolved conflicts (see hg resolve, then hg rebase --continue)
   [1]
   $ hg rebase --abort
-  saved backup bundle to $TESTTMP/abort/.hg/strip-backup/79f6d6ab7b14-cce2340e-backup.hg
   rebase aborted
-BROKEN: C got stripped
   $ hg tglog
-  o  2: ef8c0fe0897b D
+  o  3: 79f6d6ab7b14 C
   |
-  | o  1: 594087dbaf71 B
+  | o  2: ef8c0fe0897b D
+  | |
+  o |  1: 594087dbaf71 B
   |/
   o  0: 426bada5c675 A