8020804: javac crashes when speculative attribution infers intersection type with array component

Summary: Assertion is causing javac to crash because of lack of support for arrays in intersection types
Reviewed-by: jjg

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

@@ -620,7 +620,9 @@ public class Types {
      * (ii) perform functional interface bridge calculation.
      */
     public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) {
-        Assert.check(targets.nonEmpty() && isFunctionalInterface(targets.head));
+        if (targets.isEmpty() || !isFunctionalInterface(targets.head)) {
+            return null;
+        }
         Symbol descSym = findDescriptorSymbol(targets.head.tsym);
         Type descType = findDescriptorType(targets.head);
         ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());

src/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -2970,7 +2970,9 @@ public class Attr extends JCTree.Visitor {
                 //check that functional interface class is well-formed
                 ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
                         names.empty, List.of(fExpr.targets.head), ABSTRACT);
-                chk.checkImplementations(env.tree, csym, csym);
+                if (csym != null) {
+                    chk.checkImplementations(env.tree, csym, csym);
+                }
             }
         }
     }

src/share/classes/com/sun/tools/javac/comp/Infer.java

@@ -1240,7 +1240,8 @@ public class Infer {
         CAPTURED(InferenceBound.UPPER) {
             @Override
             public boolean accepts(UndetVar t, InferenceContext inferenceContext) {
-                return !inferenceContext.free(t.getBounds(InferenceBound.UPPER, InferenceBound.LOWER));
+                return t.isCaptured() &&
+                        !inferenceContext.free(t.getBounds(InferenceBound.UPPER, InferenceBound.LOWER));
             }
 
             @Override

test/tools/javac/lambda/8020804/T8020804.java

+/*
+ * Copyright (c) 2013, 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 8020804
+ * @summary javac crashes when speculative attribution infers intersection type with array component
+ * @compile T8020804.java
+ */
+
+import java.util.*;
+
+class T8020804 {
+    interface Supplier<D> {
+        D make();
+    }
+
+    void m(Object o) { }
+    void m(char[] c) { }
+
+    <C extends Collection<?>> C g(Supplier<C> sc) { return null; }
+
+    void test() {
+        m(g(LinkedList<Double>::new));
+    }
+}