context.status: remove incorrect swapping of added/removed in workingctx

The comment in workingctx.status() says that "calling 'super' subtly
reveresed the contexts", but that is simply not true, so we should not
be swapping added and removed fields.

mercurial/context.py

@@ -1499,13 +1499,9 b' class workingctx(committablectx):'
                listclean=False, listunknown=False, listsubrepos=False):
         # yet to be determined: what to do if 'other' is a 'workingctx' or a
         # 'memctx'?
-        s = super(workingctx, self).status(other, match, listignored, listclean,
-                                           listunknown, listsubrepos)
-        # calling 'super' subtly reveresed the contexts, so we flip the results
-        # (s[1] is 'added' and s[2] is 'removed')
-        s = list(s)
-        s[1], s[2] = s[2], s[1]
-        return scmutil.status(*s)
+        return super(workingctx, self).status(other, match, listignored,
+                                              listclean, listunknown,
+                                              listsubrepos)
 
 class committablefilectx(basefilectx):
     """A committablefilectx provides common functionality for a file context

tests/test-diff-reverse.t

@@ -42,3 +42,24 b''
   -g
   -h
 
+should show removed file 'a' as being added
+  $ hg revert a
+  $ hg rm a
+  $ hg diff --reverse --nodates a
+  diff -r 2855cdcfcbb7 a
+  --- /dev/null
+  +++ b/a
+  @@ -0,0 +1,3 @@
+  +d
+  +e
+  +f
+
+should show added file 'b' as being removed
+  $ echo b >> b
+  $ hg add b
+  $ hg diff --reverse --nodates b
+  diff -r 2855cdcfcbb7 b
+  --- a/b
+  +++ /dev/null
+  @@ -1,1 +0,0 @@
+  -b