--- a/CHANGELOG	Thu Oct 25 11:32:43 2018 +0200
+++ b/CHANGELOG	Wed Oct 17 14:47:38 2018 +0200
@@ -1,10 +1,15 @@
 Changelog
 =========
 
-8.3.0 - in pprogress
+8.4.0 - in progress
 -------------------
 
- * use "new" unstabilities vocabulary in help
+  * use "new" unstabilities vocabulary in help
+
+8.3.1 - in progress
+-------------------
+
+  * evolve+topic: fix possible crash during content-divergence evolution
 
 8.3.0 -- 2018-10-12
 -------------------

--- a/hgext3rd/topic/__init__.py	Thu Oct 25 11:32:43 2018 +0200
+++ b/hgext3rd/topic/__init__.py	Wed Oct 17 14:47:38 2018 +0200
@@ -143,7 +143,6 @@
     constants,
     destination,
     discovery,
-    evolvebits,
     flow,
     randomname,
     revset as topicrevset,
@@ -240,19 +239,13 @@
 
 def _contexttopicidx(self):
     topic = self.topic()
-    if not topic:
+    if not topic or self.obsolete():
         # XXX we might want to include s0 here,
         # however s0 is related to  'currenttopic' which has no place here.
         return None
     revlist = stack.stack(self._repo, topic=topic)
     try:
         return revlist.index(self.rev())
-    except ValueError:
-        if self.obsolete():
-            succ = evolvebits._singlesuccessor(self._repo, self)
-            if succ not in revlist:
-                return None
-            return revlist.index(succ)
     except IndexError:
         # Lets move to the last ctx of the current topic
         return None

--- a/tests/test-topic-stack-complex.t	Thu Oct 25 11:32:43 2018 +0200
+++ b/tests/test-topic-stack-complex.t	Wed Oct 17 14:47:38 2018 +0200
@@ -168,3 +168,12 @@
   s2: split1
   s1: Added a and b
   s0^ Added foo (base)
+
+  $ hg evolve --content-divergent -r ec94a1ed1330
+  merge:[s5] Added e and f
+  with: [s4] Added e and f
+  base: [s] Added e and f
+  updating to "local" side of the conflict: ec94a1ed1330
+  merging "other" content-divergent changeset 'f2eff98490d2'
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  working directory is now at 8faad6276dc6