manifest: define and implement rev() on manifestlog Various code is accessing repo.manifestlog._revlog - a private attribute. This bypasses our interface and makes it difficult to implement non-revlog manifest storage. This commit adds a rev() method to the manifestlog interface and class and teaches callers to use it. Ideally this method wouldn't exist, as very few consumers should need to resolve the revision number of a manifest. Again, the primary goal of interface work is to establish and use interfaces first and to improve them later. Differential Revision: https://phab.mercurial-scm.org/D3882

--- a/mercurial/logcmdutil.py	Mon Jul 02 11:14:13 2018 -0700
+++ b/mercurial/logcmdutil.py	Wed Jul 04 12:12:49 2018 -0700
@@ -228,7 +228,7 @@
 
         if self.ui.debugflag and rev is not None:
             mnode = ctx.manifestnode()
-            mrev = self.repo.manifestlog._revlog.rev(mnode)
+            mrev = self.repo.manifestlog.rev(mnode)
             self.ui.write(columns['manifest']
                           % scmutil.formatrevnode(self.ui, mrev, mnode),
                           label='ui.debug log.manifest')