diff -r 000000000000 -r 6474c204b198 dom/bindings/parser/tests/test_duplicate_qualifiers.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/parser/tests/test_duplicate_qualifiers.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,84 @@
+def WebIDLTest(parser, harness):
+    threw = False
+    try:
+        parser.parse("""
+            interface DuplicateQualifiers1 {
+              getter getter byte foo(unsigned long index);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    threw = False
+    try:
+        parser.parse("""
+            interface DuplicateQualifiers2 {
+              setter setter byte foo(unsigned long index, byte value);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    threw = False
+    try:
+        parser.parse("""
+            interface DuplicateQualifiers3 {
+              creator creator byte foo(unsigned long index, byte value);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    threw = False
+    try:
+        parser.parse("""
+            interface DuplicateQualifiers4 {
+              deleter deleter byte foo(unsigned long index);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    threw = False
+    try:
+        parser.parse("""
+            interface DuplicateQualifiers5 {
+              getter deleter getter byte foo(unsigned long index);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    threw = False
+    try:
+        results = parser.parse("""
+            interface DuplicateQualifiers6 {
+              creator setter creator byte foo(unsigned long index, byte value);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")