dirstate: add an explicit `possibly_dirty` parameter to `_addpath`

This lets says what we mean instead of using magic value. The lower level can
then decide how to express that.

Differential Revision: https://phab.mercurial-scm.org/D10932

mercurial/dirstate.py

@@ -446,6 +446,7 b' class dirstate(object):'
         size=NONNORMAL,
         mtime=AMBIGUOUS_TIME,
         from_p2=False,
+        possibly_dirty=False,
     ):
         oldstate = self[f]
         if state == b'a' or oldstate == b'r':
@@ -466,6 +467,8 b' class dirstate(object):'
         if from_p2:
             size = FROM_P2
             mtime = AMBIGUOUS_TIME
+        elif possibly_dirty:
+            mtime = AMBIGUOUS_TIME
         else:
             assert size != FROM_P2
             if size != NONNORMAL:
@@ -522,7 +525,7 b' class dirstate(object):'
                     return
                 if entry[0] == b'm' or entry[0] == b'n' and entry[2] == FROM_P2:
                     return
-        self._addpath(f, b'n', 0)
+        self._addpath(f, b'n', 0, possibly_dirty=True)
         self._map.copymap.pop(f, None)
 
     def otherparent(self, f):