5 files changed, 67 insertions, 3 deletions
diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index ea9bf43..a246711 100644
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -19,6 +19,8 @@ RELEASE 0.04 -
 
   - Allow LIBS and LIBPATH to be strings, not just arrays.
 
+  - Print a traceback if a Python-function builder throws an exception.
+
   From Steven Knight:
 
   - Fix using a directory as a Default(), and allow Default() to
@@ -46,6 +48,8 @@ RELEASE 0.04 -
     surround $_INCDIRS and $_LIBDIRS so we don't rebuild in response
     to changes to -I or -L options.
 
+  - Add the Ignore() method to ignore dependencies.
+
   From Steve Leblanc:
 
   - Add var=value command-line arguments.
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 612ae9a..3c1ee43 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -174,6 +174,17 @@ class Environment:
 	    tlist = tlist[0]
 	return tlist
 
+    def Ignore(self, target, dependency):
+        """Ignore a dependency."""
+        tlist = SCons.Util.scons_str2nodes(target)
+        dlist = SCons.Util.scons_str2nodes(dependency)
+        for t in tlist:
+            t.add_ignore(dlist)
+
+        if len(tlist) == 1:
+            tlist = tlist[0]
+        return tlist
+
     def Dictionary(self, *args):
 	if not args:
 	    return self._dict
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index a65cc33..59f3c78 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -258,6 +258,17 @@ class EnvironmentTestCase(unittest.TestCase):
 	assert d.__class__.__name__ == 'File'
 	assert d.path == 'Environment.py'
 
+    def test_Ignore(self):
+        """Test the explicit Ignore method."""
+        env = Environment()
+        t = env.Ignore(target='targ.py', dependency='dep.py')
+        assert t.__class__.__name__ == 'File'
+        assert t.path == 'targ.py'
+        assert len(t.ignore) == 1
+        i = t.ignore[0]
+        assert i.__class__.__name__ == 'File'
+        assert i.path == 'dep.py'
+
     def test_Command(self):
         """Test the Command() method."""
         env = Environment()
diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index 1050767..aa9dccb 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -312,6 +312,38 @@ class NodeTestCase(unittest.TestCase):
         assert node.implicit[3] == [two, three]
         assert node.implicit[4] == [three, four, one]
 
+    def test_add_ignore(self):
+        """Test adding files whose dependencies should be ignored.
+        """
+        node = SCons.Node.Node()
+        assert node.ignore == []
+
+        zero = SCons.Node.Node()
+        try:
+            node.add_ignore(zero)
+        except TypeError:
+            pass
+        else:
+            assert 0
+
+        one = SCons.Node.Node()
+        two = SCons.Node.Node()
+        three = SCons.Node.Node()
+        four = SCons.Node.Node()
+
+        node.add_ignore([one])
+        assert node.ignore == [one]
+        node.add_ignore([two, three])
+        assert node.ignore == [one, two, three]
+        node.add_ignore([three, four, one])
+        assert node.ignore == [one, two, three, four]
+
+        assert zero.get_parents() == []
+        assert one.get_parents() == [node]
+        assert two.get_parents() == [node]
+        assert three.get_parents() == [node]
+        assert four.get_parents() == [node]
+
     def test_scan(self):
         """Test Scanner functionality"""
         class DummyScanner:
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index c641895..03705f7 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -59,6 +59,7 @@ class Node:
         self.sources = []       # source files used to build node
         self.depends = []       # explicit dependencies (from Depends)
         self.implicit = {}	# implicit (scanned) dependencies
+        self.ignore = []	# dependencies to ignore
         self.parents = []
         self.wkids = None       # Kids yet to walk, when it's an array
 	self.builder = None
@@ -167,6 +168,10 @@ class Node:
 	"""Adds dependencies. The depend argument must be a list."""
         self._add_child(self.depends, depend)
 
+    def add_ignore(self, depend):
+        """Adds dependencies to ignore. The depend argument must be a list."""
+        self._add_child(self.ignore, depend)
+
     def add_source(self, source):
 	"""Adds sources. The source argument must be a list."""
         self._add_child(self.sources, source)
@@ -201,9 +206,10 @@ class Node:
 
     def children(self):
         #XXX Need to remove duplicates from this
-        return self.sources \
-               + self.depends \
-               + reduce(lambda x, y: x + y, self.implicit.values(), [])
+        return filter(lambda x, i=self.ignore: x not in i,
+                      self.sources \
+                      + self.depends \
+                      + reduce(lambda x, y: x + y, self.implicit.values(), []))
 
     def get_parents(self):
         return self.parents