diff -r 000000000000 -r 6474c204b198 dom/bindings/parser/tests/test_putForwards.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/parser/tests/test_putForwards.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,107 @@
+def WebIDLTest(parser, harness):
+    threw = False
+    try:
+        parser.parse("""
+            interface I {
+              [PutForwards=B] readonly attribute long A;
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset();
+    threw = False
+    try:
+        parser.parse("""
+            interface I {
+              [PutForwards=B] readonly attribute J A;
+            };
+            interface J {
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset();
+    threw = False
+    try:
+        parser.parse("""
+            interface I {
+              [PutForwards=B] attribute J A;
+            };
+            interface J {
+              attribute long B;
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset();
+    threw = False
+    try:
+        parser.parse("""
+            interface I {
+              [PutForwards=B] static readonly attribute J A;
+            };
+            interface J {
+              attribute long B;
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset();
+    threw = False
+    try:
+        parser.parse("""
+            callback interface I {
+              [PutForwards=B] readonly attribute J A;
+            };
+            interface J {
+              attribute long B;
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset();
+    threw = False
+    try:
+        parser.parse("""
+            interface I {
+              [PutForwards=C] readonly attribute J A;
+              [PutForwards=C] readonly attribute J B;
+            };
+            interface J {
+              [PutForwards=D] readonly attribute K C;
+            };
+            interface K {
+              [PutForwards=A] readonly attribute I D;
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")