8144580: java.lang.AssertionError: Missing type variable in where clause: T

Type variable comparisons should ignore type annotations.

Reviewed-by: mcimadamore

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java

@@ -368,6 +368,10 @@ public abstract class Type extends AnnoConstruct implements TypeMirror {
                 accept(stripMetadata, null) :
                 this;
     }
+
+    public Type stripMetadata() {
+        return accept(stripMetadata, null);
+    }
     //where
         private final static TypeMapping<Void> stripMetadata = new TypeMapping<Void>() {
             @Override

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/util/RichDiagnosticFormatter.java

@@ -235,16 +235,16 @@ public class RichDiagnosticFormatter extends
     }
 
     private boolean unique(TypeVar typevar) {
-        typevar = (TypeVar)typevar.stripMetadataIfNeeded();
+        typevar = (TypeVar) typevar.stripMetadata();
 
         int found = 0;
         for (Type t : whereClauses.get(WhereClauseKind.TYPEVAR).keySet()) {
-            if (t.toString().equals(typevar.toString())) {
+            if (t.stripMetadata().toString().equals(typevar.toString())) {
                 found++;
             }
         }
         if (found < 1)
-            throw new AssertionError("Missing type variable in where clause " + typevar);
+            throw new AssertionError("Missing type variable in where clause: " + typevar);
         return found == 1;
     }
     //where

langtools/test/tools/javac/annotations/typeAnnotations/RichFormatterWithAnnotationsTest.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8144580
+ * @summary java.lang.AssertionError: Missing type variable in where clause: T
+ * @compile -Xlint:unchecked RichFormatterWithAnnotationsTest.java
+ */
+
+import java.lang.annotation.*;
+import java.util.*;
+
+public class RichFormatterWithAnnotationsTest {
+
+    @Target({ElementType.TYPE_USE})
+    @interface NonNull { }
+
+    public static <T> void test() {
+        final Collection<@NonNull T> c = new LinkedList<>();
+        final List<@NonNull String> l = new LinkedList<@NonNull String>((Collection<@NonNull String>) c) {
+            // empty
+        };
+    }
+}