diff --git a/hgext/largefiles/overrides.py b/hgext/largefiles/overrides.py
--- a/hgext/largefiles/overrides.py
+++ b/hgext/largefiles/overrides.py
@@ -27,7 +27,7 @@ def composelargefilematcher(match, manif
     m = copy.copy(match)
     lfile = lambda f: lfutil.standin(f) in manifest
     m._files = filter(lfile, m._files)
-    m._fmap = set(m._files)
+    m._fileroots = set(m._files)
     m._always = False
     origmatchfn = m.matchfn
     m.matchfn = lambda f: lfile(f) and origmatchfn(f)
@@ -42,7 +42,7 @@ def composenormalfilematcher(match, mani
     notlfile = lambda f: not (lfutil.isstandin(f) or lfutil.standin(f) in
             manifest or f in excluded)
     m._files = filter(notlfile, m._files)
-    m._fmap = set(m._files)
+    m._fileroots = set(m._files)
     m._always = False
     origmatchfn = m.matchfn
     m.matchfn = lambda f: notlfile(f) and origmatchfn(f)
@@ -358,7 +358,7 @@ def overridelog(orig, ui, repo, *pats, *
                     and repo.wvfs.isdir(standin):
                 m._files.append(standin)
 
-        m._fmap = set(m._files)
+        m._fileroots = set(m._files)
         m._always = False
         origmatchfn = m.matchfn
         def lfmatchfn(f):
@@ -626,7 +626,7 @@ def overridecopy(orig, ui, repo, pats, o
             m = copy.copy(match)
             lfile = lambda f: lfutil.standin(f) in manifest
             m._files = [lfutil.standin(f) for f in m._files if lfile(f)]
-            m._fmap = set(m._files)
+            m._fileroots = set(m._files)
             origmatchfn = m.matchfn
             m.matchfn = lambda f: (lfutil.isstandin(f) and
                                 (f in manifest) and
@@ -742,7 +742,7 @@ def overriderevert(orig, ui, repo, ctx, 
                 return f
             m._files = [tostandin(f) for f in m._files]
             m._files = [f for f in m._files if f is not None]
-            m._fmap = set(m._files)
+            m._fileroots = set(m._files)
             origmatchfn = m.matchfn
             def matchfn(f):
                 if lfutil.isstandin(f):
diff --git a/mercurial/match.py b/mercurial/match.py
--- a/mercurial/match.py
+++ b/mercurial/match.py
@@ -123,7 +123,7 @@ class match(object):
                 return True
 
         self.matchfn = m
-        self._fmap = set(self._files)
+        self._fileroots = set(self._files)
 
     def __call__(self, fn):
         return self.matchfn(fn)
@@ -171,17 +171,17 @@ class match(object):
 
     @propertycache
     def _dirs(self):
-        return set(util.dirs(self._fmap)) | set(['.'])
+        return set(util.dirs(self._fileroots)) | set(['.'])
 
     def visitdir(self, dir):
-        return (not self._fmap or '.' in self._fmap or
-                dir in self._fmap or dir in self._dirs or
-                any(parentdir in self._fmap
+        return (not self._fileroots or '.' in self._fileroots or
+                dir in self._fileroots or dir in self._dirs or
+                any(parentdir in self._fileroots
                     for parentdir in util.finddirs(dir)))
 
     def exact(self, f):
         '''Returns True if f is in .files().'''
-        return f in self._fmap
+        return f in self._fileroots
 
     def anypats(self):
         '''Matcher uses patterns or include/exclude.'''
@@ -276,7 +276,7 @@ class narrowmatcher(match):
                        if f.startswith(path + "/")]
         self._anypats = matcher._anypats
         self.matchfn = lambda fn: matcher.matchfn(self._path + "/" + fn)
-        self._fmap = set(self._files)
+        self._fileroots = set(self._files)
 
     def abs(self, f):
         return self._matcher.abs(self._path + "/" + f)
@@ -303,7 +303,7 @@ class icasefsmatcher(match):
         # m.exact(file) must be based off of the actual user input, otherwise
         # inexact case matches are treated as exact, and not noted without -v.
         if self._files:
-            self._fmap = set(_roots(self._kp))
+            self._fileroots = set(_roots(self._kp))
 
     def _normalize(self, patterns, default, root, cwd, auditor):
         self._kp = super(icasefsmatcher, self)._normalize(patterns, default,