6557182: Unchecked warning *and* inconvertible types

Summary: Redundant warnings are generated when casting from intersection types
Reviewed-by: jjg

src/share/classes/com/sun/tools/javac/code/Types.java

@@ -949,12 +949,16 @@ public class Types {
                 }
 
                 if (t.isCompound()) {
+                    Warner oldWarner = warnStack.head;
+                    warnStack.head = Warner.noWarnings;
                     if (!visit(supertype(t), s))
                         return false;
                     for (Type intf : interfaces(t)) {
                         if (!visit(intf, s))
                             return false;
                     }
+                    if (warnStack.head.unchecked == true)
+                        oldWarner.warnUnchecked();
                     return true;
                 }
 

test/tools/javac/cast/6557182/T6557182.java

+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @author Maurizio Cimadamore
+ * @bug     6557182
+ * @summary  Unchecked warning *and* inconvertible types
+ * @compile/fail/ref=T6557182.out -XDrawDiagnostics -Xlint:unchecked T6557182.java
+ */
+
+class T6557182 {
+
+    <T extends Number & Comparable<String>> void test1(T t) {
+        Comparable<Integer> ci = (Comparable<Integer>) t;
+    }
+
+    <T extends Number & Comparable<? extends Number>> void test2(T t) {
+        Comparable<Integer> ci = (Comparable<Integer>) t;
+    }
+}

test/tools/javac/cast/6557182/T6557182.out

+T6557182.java:35:56: compiler.err.prob.found.req: (- compiler.misc.inconvertible.types), T, java.lang.Comparable<java.lang.Integer>
+T6557182.java:39:56: compiler.warn.prob.found.req: (- compiler.misc.unchecked.cast.to.type), T, java.lang.Comparable<java.lang.Integer>
+1 error
+1 warning