A DESCRIPTION OF THE PROBLEM :
JDK 12 Compiler throws a NullPointerException, while compiling the following code:

public class LocalVarAndBreakStmtsWithSwitch {

    public Runnable greetings(AgeGroup age) {

        Runnable thread = switch (age) {
            case KIDS -> () -> System.out.println("Hi!");
            case TEENS -> {
                String greetingsFromDB = "";// load value from database
                // some other complex/ simple processing here
                break (() -> System.out.println(greetingsFromDB));
            }
            default -> () -> System.out.println("Doesn't matter");
        };

        return thread;
    }
    enum AgeGroup {KIDS, TEENS, ADULTS};
}

REGRESSION : Last worked in version 12

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a Java class with the following contents:

public class LocalVarAndBreakStmtsWithSwitch {

    public Runnable greetings(AgeGroup age) {

        Runnable thread = switch (age) {
            case KIDS -> () -> System.out.println("Hi!");
            case TEENS -> {
                String greetingsFromDB = "";// load value from database
                // some other complex/ simple processing here
                break (() -> System.out.println(greetingsFromDB));
            }
            default -> () -> System.out.println("Doesn't matter");
        };

        return thread;
    }
    enum AgeGroup {KIDS, TEENS, ADULTS};
}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Successful compilation of the class, as per the documentation of switch expressions.
ACTUAL -
> javac --release 12 --enable-preview LocalVarAndBreakStmtsWithSwitch.java

Note: LocalVarAndBreakStmtsWithSwitch.java uses preview language features.
Note: Recompile with -Xlint:preview for details.
An exception has occurred in the compiler (12). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.NullPointerException
        at jdk.compiler/com.sun.tools.javac.jvm.Code.emitop0(Code.java:567)
        at jdk.compiler/com.sun.tools.javac.jvm.Items$LocalItem.load(Items.java:397)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genArgs(Gen.java:872)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitApply(Gen.java:1808)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1709)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:853)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitExec(Gen.java:1702)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1519)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:616)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStats(Gen.java:667)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitBlock(Gen.java:1067)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1026)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genMethod(Gen.java:937)
       at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitMethodDef(Gen.java:900)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:872)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genClass(Gen.java:2345)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:756)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1635)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1603)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:973)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:311)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:170)
        at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
        at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)

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Test case not required - the source doesn't compile. NullPointerException is thrown by JDK 12 compiler.
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FREQUENCY : always