--- a/hgext3rd/topic/discovery.py	Tue Nov 07 14:21:19 2017 +0100
+++ b/hgext3rd/topic/discovery.py	Tue Nov 14 21:05:59 2017 +0100
@@ -1,5 +1,6 @@
 from __future__ import absolute_import
 
+import collections
 import weakref
 
 from mercurial.i18n import _
@@ -31,17 +32,50 @@
 
     publishing = ('phases' not in remote.listkeys('namespaces')
                   or bool(remote.listkeys('phases').get('publishing', False)))
-    if publishing or not remote.capable('topics'):
+    if ((publishing or not remote.capable('topics'))
+            and (pushoparg and not pushop.publish)):
         return orig(*args)
 
+    publishedset = ()
+    remotebranchmap = None
+    origremotebranchmap = remote.branchmap
+    if pushoparg: # < hg-4.4 do not have a --publish flag anyway
+        publishednode = [c.node() for c in pushop.outdatedphases]
+        publishedset = repo.revs('ancestors(%ln + %ln)',
+                                 publishednode,
+                                 pushop.remotephases.publicheads)
+
+        rev = repo.unfiltered().changelog.nodemap.get
+
+        def remotebranchmap():
+            # drop topic information from changeset about to be published
+            result = collections.defaultdict(list)
+            for branch, heads in origremotebranchmap().iteritems():
+                if ':' not in branch:
+                    result[branch].extend(heads)
+                else:
+                    namedbranch = branch.split(':', 1)[0]
+                    for h in heads:
+                        r = rev(h)
+                        if r is not None and r in publishedset:
+                            result[namedbranch].append(h)
+                        else:
+                            result[branch].append(h)
+            for heads in result.itervalues():
+                heads.sort()
+            return result
+
     class repocls(repo.__class__):
         # awful hack to see branch as "branch:topic"
         def __getitem__(self, key):
             ctx = super(repocls, self).__getitem__(key)
             oldbranch = ctx.branch
+            rev = ctx.rev()
 
             def branch():
                 branch = oldbranch()
+                if rev in publishedset:
+                    return branch
                 topic = ctx.topic()
                 if topic:
                     branch = "%s:%s" % (branch, topic)
@@ -56,6 +90,8 @@
 
             def branchinfo(rev):
                 branch, close = changelog.branchinfo(rev)
+                if rev in publishedset:
+                    return branch, close
                 topic = repo[rev].topic()
                 if topic:
                     branch = "%s:%s" % (branch, topic)
@@ -67,6 +103,7 @@
     oldrepocls = repo.__class__
     try:
         repo.__class__ = repocls
+        remote.branchmap = remotebranchmap
         unxx = repo.filtered('unfiltered-topic')
         repo.unfiltered = lambda: unxx
         if pushoparg:
@@ -83,6 +120,7 @@
         if 'unfiltered' in vars(repo):
             del repo.unfiltered
         repo.__class__ = oldrepocls
+        remote.branchmap = origremotebranchmap
 
 def wireprotobranchmap(orig, repo, proto):
     oldrepo = repo.__class__

--- a/tests/test-topic-flow-publish-flag.t	Tue Nov 07 14:21:19 2017 +0100
+++ b/tests/test-topic-flow-publish-flag.t	Tue Nov 14 21:05:59 2017 +0100
@@ -280,3 +280,147 @@
   |
   o  0:ea207398892e ROOT public default
   
+
+Testing --publish interaction with multiple head detection
+============================================================
+
+pushing a topic changeset, publishing it
+----------------------------------------
+
+  $ hg topic topic_A
+  marked working directory as topic: topic_A
+  $ mkcommit c_dK0
+  active topic 'topic_A' grew its first changeset
+  $ hg push -r 'desc("c_dK0")' --publish
+  pushing to $TESTTMP/bare-branch-server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  active topic 'topic_A' is now empty
+  $ hg log --rev 'sort(all(), "topo")' -GT '{rev}:{node|short} {desc} {phase} {branch} {topics}'
+  @  11:d06fc4f891e8 c_dK0 public default
+  |
+  o  10:ac4cf59f2aac c_dJ0 public default
+  |
+  o  9:fbf2be276221 c_dI0 public default
+  |
+  o  5:5576ae39eaee c_dE0 public default
+  |
+  | o  8:8e85646c135f c_oH0 draft other
+  | |
+  | o  7:d293f74a1233 c_oG0 public other
+  | |
+  | o  6:45b23c834b6a c_oF0 public other
+  |/
+  o  4:c63e7dd93a91 c_dD0 public default
+  |
+  o  3:7d56a56d2547 c_dC0 public default
+  |
+  o  2:286d02a6e2a2 c_dB0 public default
+  |
+  o  1:134bc3852ad2 c_dA0 public default
+  |
+  o  0:ea207398892e ROOT public default
+  
+
+pushing a new branch, alongside an existing topic
+-------------------------------------------------
+
+  $ hg topic topic_A
+  $ mkcommit c_dL0
+  active topic 'topic_A' grew its first changeset
+  $ hg push -r 'desc("c_dL0")'
+  pushing to $TESTTMP/bare-branch-server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  $ hg update 'desc("c_dK")'
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ mkcommit c_dM0
+  $ hg push -r 'desc("c_dM0")' --publish
+  pushing to $TESTTMP/bare-branch-server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+  $ hg log --rev 'sort(all(), "topo")' -GT '{rev}:{node|short} {desc} {phase} {branch} {topics}'
+  @  13:0d144c8b6c8f c_dM0 public default
+  |
+  | o  12:3c73f6cabf07 c_dL0 draft default topic_A
+  |/
+  o  11:d06fc4f891e8 c_dK0 public default
+  |
+  o  10:ac4cf59f2aac c_dJ0 public default
+  |
+  o  9:fbf2be276221 c_dI0 public default
+  |
+  o  5:5576ae39eaee c_dE0 public default
+  |
+  | o  8:8e85646c135f c_oH0 draft other
+  | |
+  | o  7:d293f74a1233 c_oG0 public other
+  | |
+  | o  6:45b23c834b6a c_oF0 public other
+  |/
+  o  4:c63e7dd93a91 c_dD0 public default
+  |
+  o  3:7d56a56d2547 c_dC0 public default
+  |
+  o  2:286d02a6e2a2 c_dB0 public default
+  |
+  o  1:134bc3852ad2 c_dA0 public default
+  |
+  o  0:ea207398892e ROOT public default
+  
+
+pushing a topic (publishing) alongside and existing branch head
+---------------------------------------------------------------
+
+  $ hg update 'desc("c_dK")'
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg topic topic_B
+  marked working directory as topic: topic_B
+  $ mkcommit c_dN0
+  active topic 'topic_B' grew its first changeset
+  $ hg push -r 'desc("c_dN0")' --publish
+  pushing to $TESTTMP/bare-branch-server
+  searching for changes
+  abort: push creates new remote head 4dcd0be9db96!
+  (merge or see 'hg help push' for details about pushing new heads)
+  [255]
+  $ hg log --rev 'sort(all(), "topo")' -GT '{rev}:{node|short} {desc} {phase} {branch} {topics}'
+  @  14:4dcd0be9db96 c_dN0 draft default topic_B
+  |
+  | o  13:0d144c8b6c8f c_dM0 public default
+  |/
+  | o  12:3c73f6cabf07 c_dL0 draft default topic_A
+  |/
+  o  11:d06fc4f891e8 c_dK0 public default
+  |
+  o  10:ac4cf59f2aac c_dJ0 public default
+  |
+  o  9:fbf2be276221 c_dI0 public default
+  |
+  o  5:5576ae39eaee c_dE0 public default
+  |
+  | o  8:8e85646c135f c_oH0 draft other
+  | |
+  | o  7:d293f74a1233 c_oG0 public other
+  | |
+  | o  6:45b23c834b6a c_oF0 public other
+  |/
+  o  4:c63e7dd93a91 c_dD0 public default
+  |
+  o  3:7d56a56d2547 c_dC0 public default
+  |
+  o  2:286d02a6e2a2 c_dB0 public default
+  |
+  o  1:134bc3852ad2 c_dA0 public default
+  |
+  o  0:ea207398892e ROOT public default
+