rebase: skip extinct revisions even if it has no successor in rebase set

Differential Revision: https://phab.mercurial-scm.org/D4408

hgext/rebase.py

@@ -1891,7 +1891,7 b' def _computeobsoletenotrebased(repo, reb'
                 # If 'srcrev' has a successor in rebase set but none in
                 # destination (which would be catched above), we shall skip it
                 # and its descendants to avoid divergence.
-                if any(s in destmap for s in succrevs):
+                if srcrev in extinctrevs or any(s in destmap for s in succrevs):
                     obsoletewithoutsuccessorindestination.add(srcrev)
 
     return (

tests/test-rebase-obsolete.t

@@ -1525,11 +1525,9 b' destination'
   > A
   > EOF
 
-TODO: There doesn't seem to be much reason to fail this rebase. Make it pass?
   $ hg rebase -d D -s B
-  abort: this rebase will cause divergences from: 26805aba1e60
-  (to force the rebase please set experimental.evolution.allowdivergence=True)
-  [255]
+  rebasing 1:112478962961 "B" (B)
+  note: not rebasing 3:26805aba1e60 "C" (C) and its descendants as this would cause divergence
 
   $ cd ..