dirstate: introduce a symbolic constant for the AMBIGUOUS_TIME marker

This is going to be clearer and easier to track than -1. Ultimately I would
like to get ride of this special value everywhere but in the lower level,
however we need to clarify the API first. This changeset is part of such
clarification.

Differential Revision: https://phab.mercurial-scm.org/D10928

mercurial/dirstate.py

@@ -54,6 +54,9 b' FROM_P2 = -2'
 # a special value used internally for `size` if the file is modified/merged/added
 NONNORMAL = -1
 
+# a special value used internally for `time` if the time is ambigeous
+AMBIGUOUS_TIME = -1
+
 
 class repocache(filecache):
     """filecache for files in .hg/"""
@@ -502,7 +505,7 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, NONNORMAL, -1)
+        self._addpath(f, b'n', 0, NONNORMAL, AMBIGUOUS_TIME)
         self._map.copymap.pop(f, None)
 
     def otherparent(self, f):
@@ -512,15 +515,15 b' class dirstate(object):'
             raise error.Abort(msg)
         if f in self and self[f] == b'n':
             # merge-like
-            self._addpath(f, b'm', 0, FROM_P2, -1)
+            self._addpath(f, b'm', 0, FROM_P2, AMBIGUOUS_TIME)
         else:
             # add-like
-            self._addpath(f, b'n', 0, FROM_P2, -1)
+            self._addpath(f, b'n', 0, FROM_P2, AMBIGUOUS_TIME)
         self._map.copymap.pop(f, None)
 
     def add(self, f):
         '''Mark a file added.'''
-        self._addpath(f, b'a', 0, NONNORMAL, -1)
+        self._addpath(f, b'a', 0, NONNORMAL, AMBIGUOUS_TIME)
         self._map.copymap.pop(f, None)
 
     def remove(self, f):
@@ -1537,7 +1540,7 b' class dirstatemap(object):'
         if oldstate == b"?" and "_alldirs" in self.__dict__:
             self._alldirs.addpath(f)
         self._map[f] = dirstatetuple(state, mode, size, mtime)
-        if state != b'n' or mtime == -1:
+        if state != b'n' or mtime == AMBIGUOUS_TIME:
             self.nonnormalset.add(f)
         if size == FROM_P2:
             self.otherparentset.add(f)
@@ -1581,7 +1584,7 b' class dirstatemap(object):'
         for f in files:
             e = self.get(f)
             if e is not None and e[0] == b'n' and e[3] == now:
-                self._map[f] = dirstatetuple(e[0], e[1], e[2], -1)
+                self._map[f] = dirstatetuple(e[0], e[1], e[2], AMBIGUOUS_TIME)
                 self.nonnormalset.add(f)
 
     def nonnormalentries(self):
@@ -1592,7 +1595,7 b' class dirstatemap(object):'
             nonnorm = set()
             otherparent = set()
             for fname, e in pycompat.iteritems(self._map):
-                if e[0] != b'n' or e[3] == -1:
+                if e[0] != b'n' or e[3] == AMBIGUOUS_TIME:
                     nonnorm.add(fname)
                 if e[0] == b'n' and e[2] == FROM_P2:
                     otherparent.add(fname)