--- a/hgext3rd/topic/__init__.py	Fri Aug 12 23:59:37 2016 +0200
+++ b/hgext3rd/topic/__init__.py	Sat Aug 13 01:24:10 2016 +0200
@@ -45,6 +45,7 @@
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 colortable = {'topic.active': 'green',
+              'topic.list.troubledcount': 'red',
               'topic.stack.index': 'yellow',
               'topic.stack.state.base': 'dim',
               'topic.stack.state.clean': 'green',
@@ -295,6 +296,11 @@
             fm.plain('\t(')
             fm.write('changesetcount', '%d changesets', data['changesetcount'],
                      label='topic.list.changesetcount')
+            if data['troubledcount']:
+                fm.plain(', ')
+                fm.write('troubledcount', '%d troubled',
+                         data['troubledcount'],
+                         label='topic.list.troubledcount')
             fm.plain(')')
         fm.plain('\n')
     fm.end()

--- a/hgext3rd/topic/stack.py	Fri Aug 12 23:59:37 2016 +0200
+++ b/hgext3rd/topic/stack.py	Sat Aug 13 01:24:10 2016 +0200
@@ -68,10 +68,12 @@
     """get various data about a stack
 
     :changesetcount: number of non-obsolete changesets in the stack
+    :troubledcount: number on troubled changesets
     """
     data = {}
     revs = repo.revs("topic(%s) - obsolete()", topic)
     data['changesetcount'] = len(revs)
+    data['troubledcount'] = len([r for r in revs if repo[r].troubled()])
     return data
 
 # Copied from evolve 081605c2e9b6

--- a/tests/test-topic-list.t	Fri Aug 12 23:59:37 2016 +0200
+++ b/tests/test-topic-list.t	Sat Aug 13 01:24:10 2016 +0200
@@ -173,10 +173,10 @@
 verbose
 
   $ hg topic --verbose
-     bar	(5 changesets)
+     bar	(5 changesets, 1 troubled)
      baz	(2 changesets)
    * foo	(2 changesets)
-     fuz	(3 changesets)
+     fuz	(3 changesets, 2 troubled)
 
 json
 
@@ -207,7 +207,8 @@
    {
     "active": false,
     "changesetcount": 5,
-    "topic": "bar"
+    "topic": "bar",
+    "troubledcount": 1
    },
    {
     "active": false,
@@ -222,6 +223,7 @@
    {
     "active": false,
     "changesetcount": 3,
-    "topic": "fuz"
+    "topic": "fuz",
+    "troubledcount": 2
    }
   ]