Fix matching of SNAPSHOT artifacts when customizing layers

Previously the artifact's version was used. In an artifact's version,
SNAPSHOT is replaced with the timestamped version number of a specific
snapshot. As a result, it no longer matches the *:*:*SNAPSHOT pattern.

This commit replaces switches to using the artifact's base version.
This preserves the SNAPSHOT in the version number. For non-snapshot
artifacts, the version and base version are identical.

Fixes gh-23533

Author: wilkinsona

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/ArtifactsLibraries.java

@@ -144,7 +144,7 @@ public String getArtifactId() {
 
 		@Override
 		public String getVersion() {
-			return this.artifact.getVersion();
+			return this.artifact.getBaseVersion();
 		}
 
 		@Override

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/ArtifactsLibrariesTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.maven;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedHashSet;
@@ -131,4 +132,20 @@ void renamesDuplicates() throws Exception {
 		assertThat(this.libraryCaptor.getAllValues().get(1).getName()).isEqualTo("g2-artifact-1.0.jar");
 	}
 
+	@Test
+	void libraryCoordinatesVersionUsesBaseVersionOfArtifact() throws IOException {
+		Artifact snapshotArtifact = mock(Artifact.class);
+		given(snapshotArtifact.getType()).willReturn("jar");
+		given(snapshotArtifact.getScope()).willReturn("compile");
+		given(snapshotArtifact.getGroupId()).willReturn("g1");
+		given(snapshotArtifact.getArtifactId()).willReturn("artifact");
+		given(snapshotArtifact.getVersion()).willReturn("1.0-20200929.090327-28");
+		given(snapshotArtifact.getBaseVersion()).willReturn("1.0-SNAPSHOT");
+		given(snapshotArtifact.getFile()).willReturn(new File("a"));
+		given(snapshotArtifact.getArtifactHandler()).willReturn(this.artifactHandler);
+		this.artifacts = Collections.singleton(snapshotArtifact);
+		new ArtifactsLibraries(this.artifacts, null, mock(Log.class)).doWithLibraries(
+				(library) -> assertThat(library.getCoordinates().getVersion()).isEqualTo("1.0-SNAPSHOT"));
+	}
+
 }