--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java	Sun May 02 15:55:02 2010 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java	Mon May 03 17:12:59 2010 -0700
@@ -988,6 +988,13 @@
             Env<AttrContext> catchEnv =
                 env.dup(c, env.info.dup(env.info.scope.dup()));
             Type ctype = attribStat(c.param, catchEnv);
+            if (TreeInfo.isMultiCatch(c)) {
+                //check that multi-catch parameter is marked as final
+                if ((c.param.sym.flags() & FINAL) == 0) {
+                    log.error(c.param.pos(), "multicatch.param.must.be.final", c.param.sym);
+                }
+                c.param.sym.flags_field = c.param.sym.flags() | DISJOINT;
+            }
             if (c.param.type.tsym.kind == Kinds.VAR) {
                 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
             }
@@ -2735,6 +2742,11 @@
         result = check(tree, owntype, TYP, pkind, pt);
     }
 
+    public void visitTypeDisjoint(JCTypeDisjoint tree) {
+        List<Type> componentTypes = attribTypes(tree.components, env);
+        tree.type = result = check(tree, types.lub(componentTypes), TYP, pkind, pt);
+    }
+
     public void visitTypeParameter(JCTypeParameter tree) {
         TypeVar a = (TypeVar)tree.type;
         Set<Type> boundSet = new HashSet<Type>();