Use kotlin_module not kotlin-module to identify Kotlin module metadata

See gh-16004

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Repackager.java

@@ -381,7 +381,7 @@ public class Repackager {
 			}
 			if ((entry.getName().startsWith("META-INF/")
 					&& !entry.getName().equals("META-INF/aop.xml")
-					&& !entry.getName().endsWith(".kotlin-module"))
+					&& !entry.getName().endsWith(".kotlin_module"))
 					|| entry.getName().startsWith("BOOT-INF/")
 					|| entry.getName().equals("module-info.class")) {
 				return entry;

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/RepackagerTests.java

@@ -679,15 +679,15 @@ public class RepackagerTests {
 	public void kotlinModuleMetadataMovesBeneathBootInfClassesWhenRepackaged()
 			throws Exception {
 		this.testJarFile.addClass("A.class", ClassWithMainMethod.class);
-		this.testJarFile.addFile("META-INF/test.kotlin-module",
-				this.temporaryFolder.newFile("test.kotlin-module"));
+		this.testJarFile.addFile("META-INF/test.kotlin_module",
+				this.temporaryFolder.newFile("test.kotlin_module"));
 		File source = this.testJarFile.getFile();
 		File dest = this.temporaryFolder.newFile("dest.jar");
 		Repackager repackager = new Repackager(source);
 		repackager.repackage(dest, NO_LIBRARIES);
 		try (JarFile jarFile = new JarFile(dest)) {
-			assertThat(jarFile.getEntry("META-INF/test.kotlin-module")).isNull();
-			assertThat(jarFile.getEntry("BOOT-INF/classes/META-INF/test.kotlin-module"))
+			assertThat(jarFile.getEntry("META-INF/test.kotlin_module")).isNull();
+			assertThat(jarFile.getEntry("BOOT-INF/classes/META-INF/test.kotlin_module"))
 					.isNotNull();
 		}
 	}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/jar-with-kotlin-module/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-with-kotlin-module</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+		<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<requiresUnpack>
+								<dependency>
+									<groupId>org.jetbrains.kotlin</groupId>
+									<artifactId>kotlin-compiler</artifactId>
+								</dependency>
+							</requiresUnpack>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+				<configuration>
+					<archive>
+						<manifestEntries>
+							<Not-Used>Foo</Not-Used>
+						</manifestEntries>
+					</archive>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.jetbrains.kotlin</groupId>
+				<artifactId>kotlin-maven-plugin</artifactId>
+				<version>@kotlin.version@</version>
+				<executions>
+					<execution>
+						<id>compile</id>
+						<phase>process-resources</phase>
+						<goals>
+							<goal>compile</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>test-compile</id>
+						<phase>process-test-resources</phase>
+						<goals>
+							<goal>compile</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>javax.servlet</groupId>
+			<artifactId>javax.servlet-api</artifactId>
+			<version>@servlet-api.version@</version>
+			<scope>provided</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-stdlib-jdk8</artifactId>
+			<version>@kotlin.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-reflect</artifactId>
+			<version>@kotlin.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-compiler</artifactId>
+			<version>@kotlin.version@</version>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/jar-with-kotlin-module/src/main/kotlin/org/test/SampleApplication.kt

+/*
+ * Copyright 2012-2017 the original author or authors.
+ *
+ * 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.
+ */
+
+@file:JvmName("SampleApplication")
+package org.test;
+
+fun main(args: Array<String>) {
+
+}
\ No newline at end of file

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/jar-with-kotlin-module/verify.groovy

+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * 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.
+ */
+
+import java.io.*;
+import org.springframework.boot.maven.*;
+
+File f = new File( basedir, "target/jar-with-kotlin-module-0.0.1.BUILD-SNAPSHOT.jar");
+new Verify.JarArchiveVerification(f, Verify.SAMPLE_APP) {
+	@Override
+	protected void verifyZipEntries(Verify.ArchiveVerifier verifier) throws Exception {
+		super.verifyZipEntries(verifier)
+		verifier.assertHasEntryNameStartingWith("BOOT-INF/classes/META-INF/jar-with-kotlin-module.kotlin_module")
+		verifier.assertHasUnpackEntry("BOOT-INF/lib/kotlin-compiler-")
+		verifier.assertHasNonUnpackEntry("BOOT-INF/lib/kotlin-stdlib-")
+		verifier.assertHasNonUnpackEntry("BOOT-INF/lib/kotlin-reflect-")
+	}
+}.verify();