revert: call status against revert target too

We now call status against the target (and possibly against the working
directory parent is different). We do not use the information from the two
sources yet, but this is coming soon.

We need the status information aganst the dirstate in all case because we need
to be able to backup local modification.

mercurial/cmdutil.py

@@ -2366,10 +2366,30 def revert(ui, repo, ctx, parents, *pats
         # get the list of subrepos that must be reverted
         targetsubs = sorted(s for s in ctx.substate if m(s))
 
-        # Find status of all file in `names`. (Against working directory parent)
+        # Find status of all file in `names`.
         m = scmutil.matchfiles(repo, names)
-        changes = repo.status(node1=parent, match=m)[:4]
-        dsmodified, dsadded, dsremoved, dsdeleted = map(set, changes)
+
+        changes = repo.status(node1=node, match=m, clean=True)
+        modified = set(changes[0])
+        added    = set(changes[1])
+        removed  = set(changes[2])
+        deleted  = set(changes[3])
+
+        # We need to account for the state of file in the dirstate
+        #
+        # Even, when we revert agains something else than parent. this will
+        # slightly alter the behavior of revert (doing back up or not, delete
+        # or just forget etc)
+        if parent == node:
+            dsmodified = modified
+            dsadded = added
+            dsremoved = removed
+            modified, added, removed = set(), set(), set()
+        else:
+            changes = repo.status(node1=parent, match=m)
+            dsmodified = set(changes[0])
+            dsadded    = set(changes[1])
+            dsremoved  = set(changes[2])
 
         # if f is a rename, update `names` to also revert the source
         cwd = repo.getcwd()
@@ -2395,8 +2415,8 def revert(ui, repo, ctx, parents, *pats
         dsadded -= missingadded
         missingremoved = dsremoved - smf
         dsremoved -= missingremoved
-        missingdeleted = dsdeleted - smf
-        dsdeleted -= missingdeleted
+        missingdeleted = deleted - smf
+        deleted -= missingdeleted
 
         # action to be actually performed by revert
         # (<list of file>, message>) tuple
@@ -2416,7 +2436,7 def revert(ui, repo, ctx, parents, *pats
             (missingadded,     (actions['remove'],   False)),
             (dsremoved,        (actions['undelete'], True)),
             (missingremoved,   (None,                False)),
-            (dsdeleted,        (actions['revert'],   False)),
+            (deleted,          (actions['revert'],   False)),
             (missingdeleted,   (actions['remove'],   False)),
             )