Use application name as convention for distribution's base name

Closes gh-12232

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/ApplicationPluginAction.java

@@ -29,6 +29,7 @@ import org.gradle.api.distribution.Distribution;
 import org.gradle.api.distribution.DistributionContainer;
 import org.gradle.api.file.CopySpec;
 import org.gradle.api.file.FileCollection;
+import org.gradle.api.internal.IConventionAware;
 import org.gradle.api.plugins.ApplicationPlugin;
 import org.gradle.api.plugins.ApplicationPluginConvention;
 import org.gradle.jvm.application.scripts.TemplateBasedScriptGenerator;
@@ -49,6 +50,10 @@ final class ApplicationPluginAction implements PluginApplicationAction {
 		DistributionContainer distributions = project.getExtensions()
 				.getByType(DistributionContainer.class);
 		Distribution distribution = distributions.create("boot");
+		if (distribution instanceof IConventionAware) {
+			((IConventionAware) distribution).getConventionMapping().map("baseName",
+					() -> applicationConvention.getApplicationName() + "-boot");
+		}
 		CreateBootStartScripts bootStartScripts = project.getTasks()
 				.create("bootStartScripts", CreateBootStartScripts.class);
 		bootStartScripts.setDescription("Generates OS-specific start scripts to run the"
@@ -71,7 +76,7 @@ final class ApplicationPluginAction implements PluginApplicationAction {
 		bootStartScripts.getConventionMapping().map("outputDir",
 				() -> new File(project.getBuildDir(), "bootScripts"));
 		bootStartScripts.getConventionMapping().map("applicationName",
-				() -> applicationConvention.getApplicationName());
+				applicationConvention::getApplicationName);
 		CopySpec binCopySpec = project.copySpec().into("bin").from(bootStartScripts);
 		binCopySpec.setFileMode(0x755);
 		distribution.getContents().with(binCopySpec);

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/plugin/ApplicationPluginActionIntegrationTests.java

@@ -133,6 +133,21 @@ public class ApplicationPluginActionIntegrationTests {
 				name + "-boot/bin/" + name + ".bat");
 	}
 
+	@Test
+	public void applicationNameCanBeUsedToCustomizeDistributionName() throws IOException {
+		assertThat(
+				this.gradleBuild.build("bootDistTar").task(":bootDistTar").getOutcome())
+						.isEqualTo(TaskOutcome.SUCCESS);
+		File distribution = new File(this.gradleBuild.getProjectDir(),
+				"build/distributions/custom-boot.tar");
+		assertThat(distribution).isFile();
+		String name = this.gradleBuild.getProjectDir().getName();
+		assertThat(tarEntryNames(distribution)).containsExactlyInAnyOrder("custom-boot/",
+				"custom-boot/lib/", "custom-boot/lib/" + name + ".jar",
+				"custom-boot/bin/", "custom-boot/bin/custom",
+				"custom-boot/bin/custom.bat");
+	}
+
 	private List<String> zipEntryNames(File distribution) throws IOException {
 		List<String> entryNames = new ArrayList<>();
 		try (ZipFile zipFile = new ZipFile(distribution)) {

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/ApplicationPluginActionIntegrationTests-applicationNameCanBeUsedToCustomizeDistributionName.gradle

+buildscript {
+	dependencies {
+		classpath files(pluginClasspath.split(','))
+	}
+}
+
+apply plugin: 'org.springframework.boot'
+apply plugin: 'application'
+apply plugin: 'java'
+
+applicationName = 'custom'
+
+bootJar {
+	mainClassName = 'com.example.ExampleApplication'
+}