/*
 * JBoss, Home of Professional Open Source.
 *
 * Copyright 2017 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jboss.logmanager;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.jboss.modules.Module;
import org.jboss.modules.Version;

/**
 * @author <a href="mailto:david.lloyd@redhat.com">David M. Lloyd</a>
 */
final class JDKSpecific {
    private JDKSpecific() {}

    private static final Gateway GATEWAY;
    private static final boolean JBOSS_MODULES;
    private static final boolean MODULAR_JVM;

    static {
        GATEWAY = AccessController.doPrivileged(new PrivilegedAction<Gateway>() {
            public Gateway run() {
                return new Gateway();
            }
        });
        boolean jbossModules = false;
        try {
            Module.getStartTime();
            jbossModules = true;
        } catch (Throwable ignored) {}
        JBOSS_MODULES = jbossModules;

        // Get the current Java version and determine, by JVM version level, if this is a modular JDK
        final String value = AccessController.doPrivileged(new PrivilegedAction<String>() {
            @Override
            public String run() {
                return System.getProperty("java.specification.version");
            }
        });
        // Shouldn't happen, but we'll assume we're not a modular environment
        boolean modularJvm = false;
        if (value != null) {
            final Matcher matcher = Pattern.compile("^(?:1\\.)?(\\d+)$").matcher(value);
            if (matcher.find()) {
                modularJvm = Integer.parseInt(matcher.group(1)) >= 9;
            }
        }
        MODULAR_JVM = modularJvm;
    }

    static final class Gateway extends SecurityManager {
        protected Class<?>[] getClassContext() {
            return super.getClassContext();
        }
    }

    /**
     * Determines whether or not this is a modular JVM. The version of the {@code java.specification.version} is checked
     * to determine if the version is greater than or equal to 9. This is required to disable specific features/hacks
     * for older JVM's when the log manager is loaded on the boot class path which doesn't support multi-release JAR's.
     *
     * @return {@code true} if determined to be a modular JVM, otherwise {@code false}
     */
    static boolean isModularJvm() {
        return MODULAR_JVM;
    }

    static Class<?> findCallingClass(Set<ClassLoader> rejectClassLoaders) {
        for (Class<?> caller : GATEWAY.getClassContext()) {
            final ClassLoader classLoader = caller.getClassLoader();
            if (classLoader != null && ! rejectClassLoaders.contains(classLoader)) {
                return caller;
            }
        }
        return null;
    }

    static Collection<Class<?>> findCallingClasses(Set<ClassLoader> rejectClassLoaders) {
        final Collection<Class<?>> result = new LinkedHashSet<>();
        for (Class<?> caller : GATEWAY.getClassContext()) {
            final ClassLoader classLoader = caller.getClassLoader();
            if (classLoader != null && ! rejectClassLoaders.contains(classLoader)) {
                result.add(caller);
            }
        }
        return result;
    }

    static void calculateCaller(ExtLogRecord logRecord) {
        final String loggerClassName = logRecord.getLoggerClassName();
        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
        final Class<?>[] classes = GATEWAY.getClassContext();
        // The stack trace may be missing classes, but the class context is not, so if we find a mismatch, we skip the class context items.
        int i = 1, j = 0;
        Class<?> clazz = classes[i++];
        StackTraceElement element = stackTrace[j++];
        boolean found = false;
        for (;;) {
            if (clazz.getName().equals(element.getClassName())) {
                if (clazz.getName().equals(loggerClassName)) {
                    // next entry could be the one we want!
                    found = true;
                } else {
                    if (found) {
                        logRecord.setSourceClassName(element.getClassName());
                        logRecord.setSourceMethodName(element.getMethodName());
                        logRecord.setSourceFileName(element.getFileName());
                        logRecord.setSourceLineNumber(element.getLineNumber());
                        if (JBOSS_MODULES) {
                            calculateModule(logRecord, clazz);
                        }
                        return;
                    }
                }
                if (j == classes.length) {
                    logRecord.setUnknownCaller();
                    return;
                }
                element = stackTrace[j ++];
            }
            if (i == classes.length) {
                logRecord.setUnknownCaller();
                return;
            }
            clazz = classes[i ++];
        }
    }

    private static void calculateModule(final ExtLogRecord logRecord, final Class<?> clazz) {
        final Module module = Module.forClass(clazz);
        if (module != null) {
            logRecord.setSourceModuleName(module.getName());
            final Version version = module.getVersion();
            if (version != null) {
                logRecord.setSourceModuleVersion(version.toString());
            } else {
                logRecord.setSourceModuleVersion(null);
            }
        }
    }
}

@@ -5407,31 +5407,34 @@
    if (j == 
-classes
+stackTrace
 .length) %7B%0A 

Check the correct array for the index.