8278834: Error "Cannot read field "sym" because "this.lvar[od]" is nu…

…ll" when compiling

Reviewed-by: phh
Backport-of: be0538d7c8e2cbfa599dbcb4c5c69533678a8421

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransPatterns.java

@@ -664,11 +664,14 @@ public void visitLambda(JCLambda tree) {
     @Override
     public void visitClassDef(JCClassDecl tree) {
         ClassSymbol prevCurrentClass = currentClass;
+        MethodSymbol prevMethodSym = currentMethodSym;
         try {
             currentClass = tree.sym;
+            currentMethodSym = null;
             super.visitClassDef(tree);
         } finally {
             currentClass = prevCurrentClass;
+            currentMethodSym = prevMethodSym;
         }
     }
 

test/langtools/tools/javac/patterns/BindingsInitializer.java

@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2022, 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 8278834
+ * @summary Verify pattern matching nested inside initializers of classes nested in methods
+ *          works correctly.
+ * @library /tools/lib /tools/javac/lib
+ * @modules
+ *      jdk.compiler/com.sun.tools.javac.api
+ *      jdk.compiler/com.sun.tools.javac.file
+ *      jdk.compiler/com.sun.tools.javac.main
+ *      jdk.compiler/com.sun.tools.javac.util
+ * @build toolbox.ToolBox toolbox.JavacTask
+ * @build combo.ComboTestHelper
+ * @compile BindingsInitializer.java
+ * @run main BindingsInitializer
+ */
+
+import combo.ComboInstance;
+import combo.ComboParameter;
+import combo.ComboTask;
+import combo.ComboTestHelper;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import toolbox.ToolBox;
+
+public class BindingsInitializer extends ComboInstance<BindingsInitializer> {
+    protected ToolBox tb;
+
+    BindingsInitializer() {
+        super();
+        tb = new ToolBox();
+    }
+
+    public static void main(String... args) throws Exception {
+        new ComboTestHelper<BindingsInitializer>()
+                .withDimension("OUTER", (x, outer) -> x.outer = outer, Outer.values())
+                .withDimension("MIDDLE", (x, middle) -> x.middle = middle, Middle.values())
+                .withDimension("INNER", (x, inner) -> x.inner = inner, Inner.values())
+                .withDimension("TEST", (x, test) -> x.test = test, Test.values())
+                .run(BindingsInitializer::new);
+    }
+
+    private Outer outer;
+    private Middle middle;
+    private Inner inner;
+    private Test test;
+
+    private static final String MAIN_TEMPLATE =
+            """
+            public class Test {
+                private static Object obj = "";
+                #{OUTER}
+            }
+            """;
+
+    @Override
+    protected void doWork() throws Throwable {
+        Path base = Paths.get(".");
+
+        ComboTask task = newCompilationTask()
+                .withSourceFromTemplate(MAIN_TEMPLATE, pname -> switch (pname) {
+                        case "OUTER" -> outer;
+                        case "MIDDLE" -> middle;
+                        case "INNER" -> inner;
+                        case "TESST" -> test;
+                        default -> throw new UnsupportedOperationException(pname);
+                    });
+
+        task.generate(result -> {
+            if (result.hasErrors()) {
+                throw new AssertionError("Unexpected result: " + result.compilationInfo());
+            }
+        });
+    }
+
+    public enum Outer implements ComboParameter {
+        NONE("#{MIDDLE}"),
+        STATIC_CLASS("static class Nested { #{MIDDLE} }"),
+        CLASS("class Inner { #{MIDDLE} }");
+        private final String code;
+
+        private Outer(String code) {
+            this.code = code;
+        }
+
+        @Override
+        public String expand(String optParameter) {
+            return code;
+        }
+    }
+
+    public enum Middle implements ComboParameter {
+        STATIC_INIT("static { #{INNER} }"),
+        INIT("{ #{INNER} }"),
+        METHOD("void test() { #{INNER} }");
+        private final String code;
+
+        private Middle(String code) {
+            this.code = code;
+        }
+
+        @Override
+        public String expand(String optParameter) {
+            return code;
+        }
+    }
+
+    public enum Inner implements ComboParameter {
+        DIRECT("#{TEST}"),
+        CLASS_STATIC_INIT("class C { static { #{TEST} } }"),
+        CLASS_INIT("class C { { #{TEST} } }"),
+        CLASS_METHOD("class C { void t() { #{TEST} } }"),
+        ANNONYMOUS_CLASS_STATIC_INIT("new Object() { static { #{TEST} } };"),
+        ANNONYMOUS_CLASS_INIT("new Object() { { #{TEST} } };"),
+        ANNONYMOUS_CLASS_METHOD("new Object() { void t() { #{TEST} } };");
+        private final String code;
+
+        private Inner(String code) {
+            this.code = code;
+        }
+
+        @Override
+        public String expand(String optParameter) {
+            return code;
+        }
+    }
+
+    public enum Test implements ComboParameter {
+        TEST("if (obj instanceof String str) System.err.println(str);");
+        private final String code;
+
+        private Test(String code) {
+            this.code = code;
+        }
+
+        @Override
+        public String expand(String optParameter) {
+            return code;
+        }
+    }
+}