revert: use modified information from both statuses

Using status information against the target ensures we are catching all
files with modifications that need reverting.

We still need to distinguish fresh modifications for backup purpose.

test-largefile is affected because it reverted a file that needs no content
change.

mercurial/cmdutil.py

@@ -2408,7 +2408,6 b' def revert(ui, repo, ctx, parents, *pats'
             dsadded    = set(changes[1])
             dsremoved  = set(changes[2])
             dsadded |= _deletedadded
-            dsmodified |= _deletedmodified
 
             # only take into account for removes between wc and target
             clean |= dsremoved - removed
@@ -2416,6 +2415,11 b' def revert(ui, repo, ctx, parents, *pats'
             # distinct between dirstate remove and other
             removed -= dsremoved
 
+            # tell newly modified apart.
+            dsmodified &= modified
+            dsmodified |= modified & dsadded # dirstate added may needs backup
+            modified -= dsmodified
+
         # if f is a rename, update `names` to also revert the source
         cwd = repo.getcwd()
         for f in dsadded:
@@ -2448,6 +2452,7 b' def revert(ui, repo, ctx, parents, *pats'
             #   file state
             #   action
             #   make backup
+            (modified,         (actions['revert'],   False)),
             (dsmodified,       (actions['revert'],   True)),
             (missingmodified,  (actions['remove'],   True)),
             (dsadded,          (actions['revert'],   True)),

tests/test-largefiles.t

@@ -1496,7 +1496,6 b' revert some files to an older revision'
   $ cat sub2/large6
   large6
   $ hg revert --no-backup -C -r '.^' sub2
-  reverting .hglf/sub2/large6 (glob)
   $ hg revert --no-backup sub2
   reverting .hglf/sub2/large6 (glob)
   $ hg status

tests/test-revert.t

@@ -912,7 +912,6 b' Misbehavior:'
 
 - report "reverting" when file needs no changes
 |
-| - reverting modified_revert
 | - reverting removed_revert
 
   $ hg revert --all --rev 'desc(base)'
@@ -930,7 +929,6 b' Misbehavior:'
   reverting modified_clean
   reverting modified_deleted
   undeleting modified_removed
-  reverting modified_revert
   undeleting modified_untracked-clean
   undeleting modified_untracked-revert
   undeleting modified_untracked-wc
@@ -1104,7 +1102,6 b' Misbehavior:'
 
 - fails to report no change to revert for
 |
-| - modified_revert
 | - removed_revert
 
   $ for file in `python ../gen-revert-cases.py filelist`; do
@@ -1180,6 +1177,7 b' Misbehavior:'
   ### revert for: modified_removed
   
   ### revert for: modified_revert
+  no changes needed to modified_revert
   
   ### revert for: modified_untracked-clean