Don't swallow the AttributeError for an expansion like .bak.

4 files changed, 48 insertions, 3 deletions

diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index cffa2b5..bce5364 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -290,7 +290,13 @@ class EntryProxy(SCons.Util.Proxy):
         try:
             return self.dictSpecialAttrs[name](self)
         except KeyError:
-            return SCons.Util.Proxy.__getattr__(self, name)
+            try:
+                attr = SCons.Util.Proxy.__getattr__(self, name)
+            except AttributeError:
+                entry = self.get()
+                classname = string.split(str(entry.__class__), '.')[-1]
+                raise AttributeError, "%s instance '%s' has no attribute '%s'" % (classname, entry.name, name)
+            return attr
 
 class Base(SCons.Node.Node):
     """A generic class for file system entries.  This class is for
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index 2237959..54c6523 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -1716,6 +1716,32 @@ class SpecialAttrTestCase(unittest.TestCase):
             assert f.posix.for_signature() == 'baz.blat_posix', \
                    f.posix.for_signature()
 
+        # Check that attempts to access non-existent attributes of the
+        # subst proxy generate the right exceptions and messages.
+        caught = None
+        try:
+            fs.Dir('ddd').get_subst_proxy().no_such_attr
+        except AttributeError, e:
+            assert str(e) == "Dir instance 'ddd' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
+        caught = None
+        try:
+            fs.Entry('eee').get_subst_proxy().no_such_attr
+        except AttributeError, e:
+            assert str(e) == "Entry instance 'eee' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
+        caught = None
+        try:
+            fs.File('fff').get_subst_proxy().no_such_attr
+        except AttributeError, e:
+            assert str(e) == "File instance 'fff' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
         fs.BuildDir('foo', 'baz')
 
         assert str(f.srcpath) == os.path.normpath('baz/bar/baz.blat'), str(f.srcpath)
diff --git a/src/engine/SCons/Sig/MD5.py b/src/engine/SCons/Sig/MD5.py
index c50dbb7..21cb24c 100644
--- a/src/engine/SCons/Sig/MD5.py
+++ b/src/engine/SCons/Sig/MD5.py
@@ -79,10 +79,10 @@ def signature(obj):
     """Generate a signature for an object
     """
     try:
-        contents = str(obj.get_contents())
+        gc = obj.get_contents
     except AttributeError:
         raise AttributeError, "unable to fetch contents of '%s'" % str(obj)
-    return hexdigest(md5.new(contents).digest())
+    return hexdigest(md5.new(str(gc())).digest())
 
 def to_string(signature):
     """Convert a signature to a string"""
diff --git a/src/engine/SCons/Sig/MD5Tests.py b/src/engine/SCons/Sig/MD5Tests.py
index 6285e87..67bdfc9 100644
--- a/src/engine/SCons/Sig/MD5Tests.py
+++ b/src/engine/SCons/Sig/MD5Tests.py
@@ -88,6 +88,19 @@ class MD5TestCase(unittest.TestCase):
         else:
             raise AttributeError, "unexpected get_contents() attribute"
 
+        # Make sure we don't eat AttributeErrors raised internally
+        # by the get_contents() method (or anything it calls).
+        caught = None
+        try:
+            class xxx:
+                def get_contents(self):
+                    raise AttributeError, "internal AttributeError"
+            signature(xxx())
+        except AttributeError, e:
+            assert str(e) == "internal AttributeError", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
     def test_to_string(self):
         assert '698d51a19d8a121ce581499d7b701668' == to_string('698d51a19d8a121ce581499d7b701668')