Patchwork [2,of,2,V2] ui: path option to declare which revisions to push by default

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -5937,16 +5937,24 @@  def push(ui, repo, dest=None, **opts):
     revs, checkout = hg.addbranchrevs(repo, repo, branches, opts.get('rev'))
     other = hg.peer(repo, opts, dest)
 
     if revs:
         revs = [repo.lookup(r) for r in scmutil.revrange(repo, revs)]
         if not revs:
             raise error.Abort(_("specified revisions evaluate to an empty set"),
                              hint=_("use different revision arguments"))
+    elif path.pushrev:
+        # It doesn't make any sense to specify ancestor revisions. So limit
+        # to DAG heads to make discovery simpler.
+        revs = scmutil.revrange(repo, ['heads(%s)' % path.pushrev])
+        revs = [repo[rev].node() for rev in revs]
+        if not revs:
+            raise error.Abort(_('default push revset for path evaluates to an '
+                                'empty set'))
 
     repo._subtoppath = dest
     try:
         # push subrepos depth-first for coherent ordering
         c = repo['']
         subs = c.substate # only repos that are committed
         for s in sorted(subs):
             result = c.sub(s).push(opts)
diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -1277,16 +1277,25 @@  behavior for that specific path. Example
     my_server:pushurl = ssh://example.com/my_path
 
 The following sub-options can be defined:
 
 ``pushurl``
    The URL to use for push operations. If not defined, the location
    defined by the path's main entry is used.
 
+``pushrev``
+   A revset defining which revisions to push by default.
+
+   When :hg:`push` is executed without a ``-r`` argument, the revset
+   defined by this sub-option is evaluated to determine what to push.
+
+   For example, a value of ``.`` will push the working directory's
+   revision by default.
+
 The following special named paths exist:
 
 ``default``
    The URL or directory to use when no source or remote is specified.
 
    :hg:`clone` will automatically define this path to the location the
    repository was cloned from.
 
diff --git a/mercurial/ui.py b/mercurial/ui.py
--- a/mercurial/ui.py
+++ b/mercurial/ui.py
@@ -1276,16 +1276,20 @@  def pushurlpathoption(ui, path, value):
     # push.
     if u.fragment:
         ui.warn(_('("#fragment" in paths.%s:pushurl not supported; '
                   'ignoring)\n') % path.name)
         u.fragment = None
 
     return str(u)
 
+@pathsuboption('pushrev', 'pushrev')
+def pushrevpathoption(ui, path, value):
+    return value
+
 class path(object):
     """Represents an individual path and its configuration."""
 
     def __init__(self, ui, name, rawloc=None, suboptions=None):
         """Construct a path from its config options.
 
         ``ui`` is the ``ui`` instance the path is coming from.
         ``name`` is the symbolic name of the path.
diff --git a/tests/test-default-push.t b/tests/test-default-push.t
--- a/tests/test-default-push.t
+++ b/tests/test-default-push.t
@@ -100,9 +100,36 @@  Windows needs a leading slash to make a 
   $ hg push
   pushing to file:/*/$TESTTMP/pushurlsource/../pushurldest (glob)
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files
 
+:pushrev is used when no -r is passed
+
+  $ cat >> .hg/hgrc << EOF
+  > default:pushrev = .
+  > EOF
+  $ hg -q up -r 0
+  $ echo head1 > foo
+  $ hg -q commit -A -m head1
+  $ hg -q up -r 0
+  $ echo head2 > foo
+  $ hg -q commit -A -m head2
+  $ hg push -f
+  pushing to file:/*/$TESTTMP/pushurlsource/../pushurldest (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+
+  $ hg --config 'paths.default:pushrev=draft()' push -f
+  pushing to file:/*/$TESTTMP/pushurlsource/../pushurldest (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+
   $ cd ..
diff --git a/tests/test-help.t b/tests/test-help.t
--- a/tests/test-help.t
+++ b/tests/test-help.t
@@ -1510,16 +1510,25 @@  Test section lookup
         my_server:pushurl = ssh://example.com/my_path
   
       The following sub-options can be defined:
   
       "pushurl"
          The URL to use for push operations. If not defined, the location
          defined by the path's main entry is used.
   
+      "pushrev"
+         A revset defining which revisions to push by default.
+  
+         When "hg push" is executed without a "-r" argument, the revset defined
+         by this sub-option is evaluated to determine what to push.
+  
+         For example, a value of "." will push the working directory's revision
+         by default.
+  
       The following special named paths exist:
   
       "default"
          The URL or directory to use when no source or remote is specified.
   
          'hg clone' will automatically define this path to the location the
          repository was cloned from.