--- a/hgext/infinitepush/__init__.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/hgext/infinitepush/__init__.py	Fri Jul 17 09:20:48 2020 +0200
@@ -466,7 +466,7 @@
 
     version = b'02'
     outgoing = discovery.outgoing(
-        bundlerepo, commonheads=bundleroots, missingheads=[unknownhead]
+        bundlerepo, commonheads=bundleroots, ancestorsof=[unknownhead]
     )
     cgstream = changegroup.makestream(bundlerepo, outgoing, version, b'pull')
     cgstream = util.chunkbuffer(cgstream).read()

--- a/mercurial/bundle2.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/bundle2.py	Fri Jul 17 09:20:48 2020 +0200
@@ -1711,7 +1711,7 @@
                 b'nbchanges', b'%d' % cg.extras[b'clcount'], mandatory=False
             )
         if opts.get(b'phases') and repo.revs(
-            b'%ln and secret()', outgoing.missingheads
+            b'%ln and secret()', outgoing.ancestorsof
         ):
             part.addparam(
                 b'targetphase', b'%d' % phases.secret, mandatory=False
@@ -1753,7 +1753,7 @@
     # consume little memory (1M heads is 40MB) b) we don't want to send the
     # part if we don't have entries and knowing if we have entries requires
     # cache lookups.
-    for node in outgoing.missingheads:
+    for node in outgoing.ancestorsof:
         # Don't compute missing, as this may slow down serving.
         fnode = cache.getfnode(node, computemissing=False)
         if fnode is not None:

--- a/mercurial/changegroup.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/changegroup.py	Fri Jul 17 09:20:48 2020 +0200
@@ -1629,7 +1629,7 @@
     repo = repo.unfiltered()
     commonrevs = outgoing.common
     csets = outgoing.missing
-    heads = outgoing.missingheads
+    heads = outgoing.ancestorsof
     # We go through the fast path if we get told to, or if all (unfiltered
     # heads have been requested (since we then know there all linkrevs will
     # be pulled by the client).

--- a/mercurial/discovery.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/discovery.py	Fri Jul 17 09:20:48 2020 +0200
@@ -93,20 +93,17 @@
       excluded is the list of missing changeset that shouldn't be sent
       remotely.
 
-      missingheads is an alias to ancestorsof, but the name is wrong and it
-      will be removed
-
     Some members are computed on demand from the heads, unless provided upfront
     by discovery.'''
 
     def __init__(
-        self, repo, commonheads=None, missingheads=None, missingroots=None
+        self, repo, commonheads=None, ancestorsof=None, missingroots=None
     ):
         # at least one of them must not be set
         assert None in (commonheads, missingroots)
         cl = repo.changelog
-        if missingheads is None:
-            missingheads = cl.heads()
+        if ancestorsof is None:
+            ancestorsof = cl.heads()
         if missingroots:
             discbases = []
             for n in missingroots:
@@ -114,14 +111,14 @@
             # TODO remove call to nodesbetween.
             # TODO populate attributes on outgoing instance instead of setting
             # discbases.
-            csets, roots, heads = cl.nodesbetween(missingroots, missingheads)
+            csets, roots, heads = cl.nodesbetween(missingroots, ancestorsof)
             included = set(csets)
-            missingheads = heads
+            ancestorsof = heads
             commonheads = [n for n in discbases if n not in included]
         elif not commonheads:
             commonheads = [nullid]
         self.commonheads = commonheads
-        self.missingheads = missingheads
+        self.ancestorsof = ancestorsof
         self._revlog = cl
         self._common = None
         self._missing = None
@@ -129,7 +126,7 @@
 
     def _computecommonmissing(self):
         sets = self._revlog.findcommonmissing(
-            self.commonheads, self.missingheads
+            self.commonheads, self.ancestorsof
         )
         self._common, self._missing = sets
 
@@ -146,8 +143,15 @@
         return self._missing
 
     @property
-    def ancestorsof(self):
-        return self.missingheads
+    def missingheads(self):
+        util.nouideprecwarn(
+            b'outgoing.missingheads never contained what the name suggests and '
+            b'was renamed to outgoing.ancestorsof. check your code for '
+            b'correctness.',
+            b'5.5',
+            stacklevel=2,
+        )
+        return self.ancestorsof
 
 
 def findcommonoutgoing(
@@ -163,7 +167,7 @@
     If commoninc is given, it must be the result of a prior call to
     findcommonincoming(repo, other, force) to avoid recomputing it here.
 
-    If portable is given, compute more conservative common and missingheads,
+    If portable is given, compute more conservative common and ancestorsof,
     to make bundles created from the instance more portable.'''
     # declare an empty outgoing object to be filled later
     og = outgoing(repo, None, None)
@@ -178,10 +182,10 @@
     # compute outgoing
     mayexclude = repo._phasecache.phaseroots[phases.secret] or repo.obsstore
     if not mayexclude:
-        og.missingheads = onlyheads or repo.heads()
+        og.ancestorsof = onlyheads or repo.heads()
     elif onlyheads is None:
         # use visible heads as it should be cached
-        og.missingheads = repo.filtered(b"served").heads()
+        og.ancestorsof = repo.filtered(b"served").heads()
         og.excluded = [ctx.node() for ctx in repo.set(b'secret() or extinct()')]
     else:
         # compute common, missing and exclude secret stuff
@@ -196,12 +200,12 @@
             else:
                 missing.append(node)
         if len(missing) == len(allmissing):
-            missingheads = onlyheads
+            ancestorsof = onlyheads
         else:  # update missing heads
-            missingheads = phases.newheads(repo, onlyheads, excluded)
-        og.missingheads = missingheads
+            ancestorsof = phases.newheads(repo, onlyheads, excluded)
+        og.ancestorsof = ancestorsof
     if portable:
-        # recompute common and missingheads as if -r<rev> had been given for
+        # recompute common and ancestorsof as if -r<rev> had been given for
         # each head of missing, and --base <rev> for each head of the proper
         # ancestors of missing
         og._computecommonmissing()
@@ -209,7 +213,7 @@
         missingrevs = {cl.rev(n) for n in og._missing}
         og._common = set(cl.ancestors(missingrevs)) - missingrevs
         commonheads = set(og.commonheads)
-        og.missingheads = [h for h in og.missingheads if h not in commonheads]
+        og.ancestorsof = [h for h in og.ancestorsof if h not in commonheads]
 
     return og
 
@@ -282,7 +286,7 @@
     # If there are no obsstore, no post processing are needed.
     if repo.obsstore:
         torev = repo.changelog.rev
-        futureheads = {torev(h) for h in outgoing.missingheads}
+        futureheads = {torev(h) for h in outgoing.ancestorsof}
         futureheads |= {torev(h) for h in outgoing.commonheads}
         allfuturecommon = repo.changelog.ancestors(futureheads, inclusive=True)
         for branch, heads in sorted(pycompat.iteritems(headssum)):

--- a/mercurial/exchange.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/exchange.py	Fri Jul 17 09:20:48 2020 +0200
@@ -503,7 +503,7 @@
     @util.propertycache
     def futureheads(self):
         """future remote heads if the changeset push succeeds"""
-        return self.outgoing.missingheads
+        return self.outgoing.ancestorsof
 
     @util.propertycache
     def fallbackheads(self):
@@ -512,20 +512,20 @@
             # not target to push, all common are relevant
             return self.outgoing.commonheads
         unfi = self.repo.unfiltered()
-        # I want cheads = heads(::missingheads and ::commonheads)
-        # (missingheads is revs with secret changeset filtered out)
+        # I want cheads = heads(::ancestorsof and ::commonheads)
+        # (ancestorsof is revs with secret changeset filtered out)
         #
         # This can be expressed as:
-        #     cheads = ( (missingheads and ::commonheads)
-        #              + (commonheads and ::missingheads))"
+        #     cheads = ( (ancestorsof and ::commonheads)
+        #              + (commonheads and ::ancestorsof))"
         #              )
         #
         # while trying to push we already computed the following:
         #     common = (::commonheads)
-        #     missing = ((commonheads::missingheads) - commonheads)
+        #     missing = ((commonheads::ancestorsof) - commonheads)
         #
         # We can pick:
-        # * missingheads part of common (::commonheads)
+        # * ancestorsof part of common (::commonheads)
         common = self.outgoing.common
         rev = self.repo.changelog.index.rev
         cheads = [node for node in self.revs if rev(node) in common]
@@ -918,7 +918,7 @@
             # obsolete or unstable changeset in missing, at
             # least one of the missinghead will be obsolete or
             # unstable. So checking heads only is ok
-            for node in outgoing.missingheads:
+            for node in outgoing.ancestorsof:
                 ctx = unfi[node]
                 if ctx.obsolete():
                     raise error.Abort(mso % ctx)
@@ -969,7 +969,7 @@
     """
     # * 'force' do not check for push race,
     # * if we don't push anything, there are nothing to check.
-    if not pushop.force and pushop.outgoing.missingheads:
+    if not pushop.force and pushop.outgoing.ancestorsof:
         allowunrelated = b'related' in bundler.capabilities.get(
             b'checkheads', ()
         )

--- a/mercurial/localrepo.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/localrepo.py	Fri Jul 17 09:20:48 2020 +0200
@@ -412,13 +412,13 @@
 
     def changegroup(self, nodes, source):
         outgoing = discovery.outgoing(
-            self._repo, missingroots=nodes, missingheads=self._repo.heads()
+            self._repo, missingroots=nodes, ancestorsof=self._repo.heads()
         )
         return changegroup.makechangegroup(self._repo, outgoing, b'01', source)
 
     def changegroupsubset(self, bases, heads, source):
         outgoing = discovery.outgoing(
-            self._repo, missingroots=bases, missingheads=heads
+            self._repo, missingroots=bases, ancestorsof=heads
         )
         return changegroup.makechangegroup(self._repo, outgoing, b'01', source)
 

--- a/mercurial/repair.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/repair.py	Fri Jul 17 09:20:48 2020 +0200
@@ -66,7 +66,7 @@
     else:
         bundletype = b"HG10UN"
 
-    outgoing = discovery.outgoing(repo, missingroots=bases, missingheads=heads)
+    outgoing = discovery.outgoing(repo, missingroots=bases, ancestorsof=heads)
     contentopts = {
         b'cg.version': cgversion,
         b'obsolescence': obsolescence,

--- a/mercurial/shelve.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/shelve.py	Fri Jul 17 09:20:48 2020 +0200
@@ -162,7 +162,7 @@
         repo = self.repo.unfiltered()
 
         outgoing = discovery.outgoing(
-            repo, missingroots=bases, missingheads=[node]
+            repo, missingroots=bases, ancestorsof=[node]
         )
         cg = changegroup.makechangegroup(repo, outgoing, cgversion, b'shelve')
 

--- a/mercurial/wireprotov1server.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/wireprotov1server.py	Fri Jul 17 09:20:48 2020 +0200
@@ -339,7 +339,7 @@
 def changegroup(repo, proto, roots):
     nodes = wireprototypes.decodelist(roots)
     outgoing = discovery.outgoing(
-        repo, missingroots=nodes, missingheads=repo.heads()
+        repo, missingroots=nodes, ancestorsof=repo.heads()
     )
     cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
     gen = iter(lambda: cg.read(32768), b'')
@@ -350,7 +350,7 @@
 def changegroupsubset(repo, proto, bases, heads):
     bases = wireprototypes.decodelist(bases)
     heads = wireprototypes.decodelist(heads)
-    outgoing = discovery.outgoing(repo, missingroots=bases, missingheads=heads)
+    outgoing = discovery.outgoing(repo, missingroots=bases, ancestorsof=heads)
     cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
     gen = iter(lambda: cg.read(32768), b'')
     return wireprototypes.streamres(gen=gen)