pull: allow a generic way to pass parameters to the pull operation

We have been feeling the need for this in extensions for quite some time. This
will be used to pass remote bookmark information around in the next changesets.

mercurial/commands.py

@@ -5120,6 +5120,7 b' def pull(ui, repo, source="default", **o'
                                           opts.get('rev'))
 
 
+        pullopargs = {}
         if opts.get('bookmark'):
             if not revs:
                 revs = []
@@ -5152,7 +5153,8 b' def pull(ui, repo, source="default", **o'
 
         modheads = exchange.pull(repo, other, heads=revs,
                                  force=opts.get('force'),
-                                 bookmarks=opts.get('bookmark', ())).cgresult
+                                 bookmarks=opts.get('bookmark', ()),
+                                 opargs=pullopargs).cgresult
         if checkout:
             checkout = str(repo.changelog.rev(checkout))
         repo._subtoppath = source

mercurial/exchange.py

@@ -886,8 +886,11 b' class transactionmanager(object):'
         if self._tr is not None:
             self._tr.release()
 
-def pull(repo, remote, heads=None, force=False, bookmarks=()):
-    pullop = pulloperation(repo, remote, heads, force, bookmarks=bookmarks)
+def pull(repo, remote, heads=None, force=False, bookmarks=(), opargs=None):
+    if opargs is None:
+        opargs = {}
+    pullop = pulloperation(repo, remote, heads, force, bookmarks=bookmarks,
+                           **opargs)
     if pullop.remote.local():
         missing = set(pullop.remote.requirements) - pullop.repo.supported
         if missing: