ADDITIONAL SYSTEM INFORMATION :
Property settings:
    file.encoding = UTF-8
    file.separator = /
    java.class.path =
    java.class.version = 69.0
    java.home = /home/ubuntu/jdk-25
    java.io.tmpdir = /tmp
    java.library.path = /usr/java/packages/lib
        /usr/lib64
        /lib64
        /lib
        /usr/lib
    java.runtime.name = Java(TM) SE Runtime Environment
    java.runtime.version = 25.0.2+10-LTS-69
    java.specification.name = Java Platform API Specification
    java.specification.vendor = Oracle Corporation
    java.specification.version = 25
    java.vendor = Oracle Corporation
    java.vendor.url = https://java.oracle.com/
    java.vendor.url.bug = https://bugreport.java.com/bugreport/
    java.version = 25.0.2
    java.version.date = 2026-01-20
    java.vm.compressedOopsMode = Zero based
    java.vm.info = mixed mode, sharing
    java.vm.name = Java HotSpot(TM) 64-Bit Server VM
    java.vm.specification.name = Java Virtual Machine Specification
    java.vm.specification.vendor = Oracle Corporation
    java.vm.specification.version = 25
    java.vm.vendor = Oracle Corporation
    java.vm.version = 25.0.2+10-LTS-69
    jdk.debug = release
    line.separator = \n
    native.encoding = UTF-8
    os.arch = amd64
    os.name = Linux
    os.version = 5.15.0-164-generic
    path.separator = :
    stderr.encoding = UTF-8
    stdin.encoding = UTF-8
    stdout.encoding = UTF-8
    sun.arch.data.model = 64
    sun.boot.library.path = /home/ubuntu/jdk-25/lib
    sun.cpu.endian = little
    sun.io.unicode.encoding = UnicodeLittle
    sun.java.launcher = SUN_STANDARD
    sun.jnu.encoding = UTF-8
    sun.management.compiler = HotSpot 64-Bit Tiered Compilers
    user.country = US
    user.home = /home/ubuntu
    user.language = en
    user.name = ubuntu

java version "25.0.2" 2026-01-20 LTS
Java(TM) SE Runtime Environment (build 25.0.2+10-LTS-69)
Java HotSpot(TM) 64-Bit Server VM (build 25.0.2+10-LTS-69, mixed mode, sharing)

A DESCRIPTION OF THE PROBLEM :
When using the javax.tools.JavaCompiler API together with JavacTask and a TaskListener, invoking JavacTask.analyze() from within the TaskListener.started(TaskEvent) callback causes the Java compiler (javac) to crash with a NullPointerException.

This occurs during the compilation phase and results in an internal compiler error rather than a user-facing diagnostic. The behavior is observed consistently on JDK 17, 21, and 25. On JDK 11, a similar failure occurs, but with a broken compiler diagnostic message instead.

This report is submitted following the compiler’s explicit request to file a bug after encountering an internal compiler error.

---------- BEGIN SOURCE ----------
import javax.tools.*;
import javax.tools.JavaFileObject.Kind;
import com.sun.source.util.*;
import java.net.URI;
import java.util.*;

public class Test {
    public static void main(String[] args) throws Exception {
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        JavaFileObject emptyFile = new SimpleJavaFileObject(
            URI.create("string:///A.java"), Kind.SOURCE) {
            @Override public CharSequence getCharContent(boolean i) { return ""; }
        };

        JavacTask task = (JavacTask) compiler.getTask(
            null, null, null, null, null, List.of(emptyFile));

        task.addTaskListener(new TaskListener() {
            @Override
            public void started(TaskEvent e) {
                try {
                    task.analyze();
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });

        task.call();
    }
}
---------- END SOURCE ----------

FREQUENCY :
ALWAYS