changeset 31202:951d95b13487

fileset: add function to switch revision where fileset will be evaluated

If the subset isn't filtered yet, i.e. if fullmatchctx, the new subset is
recalculated from scratch. Otherwise, it is narrowed by the existing subset.

--- a/mercurial/fileset.py	Sat Jan 24 19:13:39 2015 +0900
+++ b/mercurial/fileset.py	Sat Jan 24 19:41:56 2015 +0900
@@ -497,6 +497,9 @@
                 if (f in self.ctx and f not in removed) or f in unknown)
     def narrow(self, files):
         return matchctx(self.ctx, self.filter(files), self._status)
+    def switch(self, ctx, status=None):
+        subset = self.filter(_buildsubset(ctx, status))
+        return matchctx(ctx, subset, status)
 
 class fullmatchctx(matchctx):
     """A match context where any files in any revisions should be valid"""
@@ -504,12 +507,21 @@
     def __init__(self, ctx, status=None):
         subset = _buildsubset(ctx, status)
         super(fullmatchctx, self).__init__(ctx, subset, status)
+    def switch(self, ctx, status=None):
+        return fullmatchctx(ctx, status)
+
+# filesets using matchctx.switch()
+_switchcallers = [
+]
 
 def _intree(funcs, tree):
     if isinstance(tree, tuple):
         if tree[0] == 'func' and tree[1][0] == 'symbol':
             if tree[1][1] in funcs:
                 return True
+            if tree[1][1] in _switchcallers:
+                # arguments won't be evaluated in the current context
+                return False
         for s in tree[1:]:
             if _intree(funcs, s):
                 return True