8056014: Type inference may be skipped for a complex receiver generic method...

8056014: Type inference may be skipped for a complex receiver generic method in a parameter position
Summary: When checking if deferred attribution is needed for a chain of methods, stop on any method that returns any type variable, as the rest of analysis cannot use the correct type.
Reviewed-by: mcimadamore, vromero

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

@@ -1337,7 +1337,9 @@ public class DeferredAttr extends JCTree.Visitor {
                 @Override
                 public Symbol process(MethodSymbol ms) {
                     ArgumentExpressionKind kind = ArgumentExpressionKind.methodKind(ms, types);
-                    return kind != ArgumentExpressionKind.POLY ? ms.getReturnType().tsym : null;
+                    if (kind == ArgumentExpressionKind.POLY || ms.getReturnType().hasTag(TYPEVAR))
+                        return null;
+                    return ms.getReturnType().tsym;
                 }
                 @Override
                 public Symbol reduce(Symbol s1, Symbol s2) {

test/tools/javac/lambda/T8056014.java

+/*
+ * Copyright (c) 2014, 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 8056014
+ * @summary Verify that full type inference is used when calling a method on a type variable.
+ * @compile T8056014.java
+ * @run main T8056014
+ */
+
+import java.util.*;
+
+public class T8056014 {
+    public static void main(String[] args) {
+        new T8056014().run();
+    }
+
+    void run() {
+        List<S> l = Arrays.asList(new S());
+        C<S> c = new C<>(new S());
+        foo(l.get(0).copy(1));
+        foo(c.get(0).copy(1));
+    }
+
+    void foo(S d) {
+    }
+}
+
+class B {
+    public B copy(long j) {
+        throw new AssertionError("Should not get here.");
+    }
+}
+
+class S extends B {
+    public <T> T copy(int i) {
+        return null;
+    }
+}
+
+class C<T extends B> {
+    final T t;
+    public C(T t) {
+        this.t = t;
+    }
+    public T get(int i) {
+        return t;
+    }
+}