pull: skip pulling remote bookmarks with bundle2 if a value already exists

For efficiency and consistency purpose, remote bookmarks, retrieved at the time
the pull command code is doing lookup, will be reused during the core pull
operation.

A second step toward this is to avoid requesting bookmark information in
the bundle 2 if we already have them locally.

mercurial/exchange.py

@@ -1006,7 +1006,11 b' def _pullbundle2(pullop):'
     kwargs['heads'] = pullop.heads or pullop.rheads
     kwargs['cg'] = pullop.fetch
     if 'listkeys' in remotecaps:
-        kwargs['listkeys'] = ['phase', 'bookmarks']
+        kwargs['listkeys'] = ['phase']
+        if pullop.remotebookmarks is None:
+            # make sure to always includes bookmark data when migrating
+            # `hg incoming --bundle` to using this function.
+            kwargs['listkeys'].append('bookmarks')
     if not pullop.fetch:
         pullop.repo.ui.status(_("no changes found\n"))
         pullop.cgresult = 0
@@ -1038,6 +1042,9 b' def _pullbundle2(pullop):'
     for namespace, value in op.records['listkeys']:
         if namespace == 'bookmarks':
             pullop.remotebookmarks = value
+
+    # bookmark data were either already there or pulled in the bundle
+    if pullop.remotebookmarks is not None:
             _pullbookmarks(pullop)
 
 def _pullbundle2extraprepare(pullop, kwargs):