[PATCH 2 of 5 requirements-tidy] largefiles: use repo.addrequirement()

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1443724984 25200
#      Thu Oct 01 11:43:04 2015 -0700
# Node ID 8d51cc6b20a930f3c6fe0a2b7135eca696e2b8fc
# Parent  a6ba4ec0ac210f86459ae7da0a8843d6132a0d12
largefiles: use repo.addrequirement()

We have a new API to add requirements to a repo. Use it.

This removes a call to a private API and adds a
probably-should-have-been there call to repo._applyopenerreqs() by way
of switching to the new API.

diff --git a/hgext/largefiles/lfcommands.py b/hgext/largefiles/lfcommands.py
--- a/hgext/largefiles/lfcommands.py
+++ b/hgext/largefiles/lfcommands.py
@@ -117,10 +117,9 @@ def lfconvert(ui, src, dest, *pats, **op
 
             # If there were any files converted to largefiles, add largefiles
             # to the destination repository's requirements.
             if lfiles:
-                rdst.requirements.add('largefiles')
-                rdst._writerequirements()
+                rdst.addrequirement('largefiles')
         else:
             class lfsource(filemap.filemap_source):
                 def __init__(self, ui, source):
                     super(lfsource, self).__init__(ui, source, None)
diff --git a/hgext/largefiles/reposetup.py b/hgext/largefiles/reposetup.py
--- a/hgext/largefiles/reposetup.py
+++ b/hgext/largefiles/reposetup.py
@@ -364,12 +364,13 @@ def reposetup(ui, repo):
             lfcommands.uploadlfiles(ui, local, remote, toupload)
     repo.prepushoutgoinghooks.add("largefiles", prepushoutgoinghook)
 
     def checkrequireslfiles(ui, repo, **kwargs):
+        # addrequirement() no-ops. But walking data files is expensive, so do
+        # a local check to avoid that work.
         if 'largefiles' not in repo.requirements and any(
                 lfutil.shortname+'/' in f[0] for f in repo.store.datafiles()):
-            repo.requirements.add('largefiles')
-            repo._writerequirements()
+            repo.addrequirement('largefiles')
 
     ui.setconfig('hooks', 'changegroup.lfiles', checkrequireslfiles,
                  'largefiles')
     ui.setconfig('hooks', 'commit.lfiles', checkrequireslfiles, 'largefiles')