--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java	Tue Aug 20 14:33:57 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java	Tue Aug 20 15:31:12 2019 -0400
@@ -340,6 +340,11 @@
      */
     public static final long RECORD = 1L<<61;
 
+    /**
+     * Flag to mark a record constructor as a compact one
+     */
+    public static final long COMPACT_RECORD_CONSTRUCTOR = 1L<<51;
+
     /** Modifier masks.
      */
     public static final int

--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TypeEnter.java	Tue Aug 20 14:33:57 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TypeEnter.java	Tue Aug 20 15:31:12 2019 -0400
@@ -970,23 +970,25 @@
                                     constructorInvocationName == names._super) {
                                 RecordConstructorHelper helper = new RecordConstructorHelper(sym, TreeInfo.recordFields(tree));
                                 JCMethodDecl methDecl = (JCMethodDecl)def;
-                                if (constructorInvocationName == names.empty) {
-                                    JCStatement supCall = make.at(methDecl.body.pos).Exec(make.Apply(List.nil(),
-                                            make.Ident(names._super), List.nil()));
-                                    methDecl.body.stats = methDecl.body.stats.prepend(supCall);
-                                }
-                                ListBuffer<JCStatement> initializations = new ListBuffer<>();
-                                List<Name> inits = helper.inits();
-                                InitializationFinder initFinder = new InitializationFinder(inits);
-                                initFinder.scan(methDecl.body.stats);
-                                List<Name> found = initFinder.found.toList();
-                                inits = inits.diff(found);
-                                if (!inits.isEmpty()) {
-                                    for (Name initName : inits) {
-                                        initializations.add(make.Exec(make.Assign(make.Select(make.Ident(names._this),
-                                                initName), make.Ident(initName))));
+                                if ((methDecl.mods.flags & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0) {
+                                    if (constructorInvocationName == names.empty) {
+                                        JCStatement supCall = make.at(methDecl.body.pos).Exec(make.Apply(List.nil(),
+                                                make.Ident(names._super), List.nil()));
+                                        methDecl.body.stats = methDecl.body.stats.prepend(supCall);
                                     }
-                                    methDecl.body.stats = methDecl.body.stats.appendList(initializations.toList());
+                                    ListBuffer<JCStatement> initializations = new ListBuffer<>();
+                                    List<Name> inits = helper.inits();
+                                    InitializationFinder initFinder = new InitializationFinder(inits);
+                                    initFinder.scan(methDecl.body.stats);
+                                    List<Name> found = initFinder.found.toList();
+                                    inits = inits.diff(found);
+                                    if (!inits.isEmpty()) {
+                                        for (Name initName : inits) {
+                                            initializations.add(make.Exec(make.Assign(make.Select(make.Ident(names._this),
+                                                    initName), make.Ident(initName))));
+                                        }
+                                        methDecl.body.stats = methDecl.body.stats.appendList(initializations.toList());
+                                    }
                                 }
                             }
                         }

--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/parser/JavacParser.java	Tue Aug 20 14:33:57 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/parser/JavacParser.java	Tue Aug 20 15:31:12 2019 -0400
@@ -4096,6 +4096,9 @@
                         log.error(DiagnosticFlag.SYNTAX, pos, Errors.InvalidMethDeclRetTypeReq);
                     else if (annosAfterParams.nonEmpty())
                         illegal(annosAfterParams.head.pos);
+                    if (isRecord && token.kind == LBRACE) {
+                        mods.flags |= Flags.COMPACT_RECORD_CONSTRUCTOR;
+                    }
                     return List.of(methodDeclaratorRest(
                         pos, mods, null, names.init, typarams,
                         isInterface, true, isRecord, dc));

--- a/test/langtools/tools/javac/records/RecordCompilationTests.java	Tue Aug 20 14:33:57 2019 -0400
+++ b/test/langtools/tools/javac/records/RecordCompilationTests.java	Tue Aug 20 15:31:12 2019 -0400
@@ -264,9 +264,8 @@
             assertOK("record R(int x, int y) { # }", goodCtor);
 
         // Not OK to redeclare canonical without DA
-        // @@@ Should fail
-//        assertFail("", "record R(int x, int y) { # }",
-//                   "public R(int x, int y) { this.x = x; }");
+        assertFail("compiler.err.var.might.not.have.been.initialized", "record R(int x, int y) { # }",
+                   "public R(int x, int y) { this.x = x; }");
 
         // canonical ctor must be public
         assertFail("compiler.err.canonical.constructor.must.be.public", "record R(int x, int y) { # }",

--- a/test/langtools/tools/javac/records/mandated_members/MandatedMembersNotBeingEntered.java	Tue Aug 20 14:33:57 2019 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,32 +0,0 @@
-/*
- * Copyright (c) 2019, 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
- * @summary test to check that mandated members are entered
- * @compile MandatedMembersNotBeingEntered.java
- */
-
-record MandatedMembersNotBeingEntered(int i, int j) {
-    public MandatedMembersNotBeingEntered(int i, int j, Object obj) {}
-}

--- a/test/langtools/tools/javac/records/mandated_members/canonical_constructor/MethodParametersForCanonicalConstructorTest.java	Tue Aug 20 14:33:57 2019 -0400
+++ b/test/langtools/tools/javac/records/mandated_members/canonical_constructor/MethodParametersForCanonicalConstructorTest.java	Tue Aug 20 15:31:12 2019 -0400
@@ -43,7 +43,10 @@
     }
 
     record R3(int i, int j) {
-        public R3(int i, int j) {}
+        public R3(int i, int j) {
+            this.i = i;
+            this.j = j;
+        }
     }
 
     public static void main(String args[]) throws Throwable {