Restore order of additional and active profiles

This commit restores the order of additional and active profiles
so that active profiles now take precedence.

Fixes gh-26189

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/Profiles.java

@@ -145,15 +145,16 @@ private List<String> asReversedList(List<String> list) {
 		return reversed;
 	}
 
-	private List<String> asUniqueItemList(Collection<String> strings) {
-		return asUniqueItemList(strings, null);
+	private List<String> asUniqueItemList(Collection<String> profiles) {
+		return asUniqueItemList(profiles, null);
 	}
 
-	private List<String> asUniqueItemList(Collection<String> strings, Collection<String> additional) {
-		LinkedHashSet<String> uniqueItems = new LinkedHashSet<>(strings);
+	private List<String> asUniqueItemList(Collection<String> profiles, Collection<String> additional) {
+		LinkedHashSet<String> uniqueItems = new LinkedHashSet<>();
 		if (!CollectionUtils.isEmpty(additional)) {
 			uniqueItems.addAll(additional);
 		}
+		uniqueItems.addAll(profiles);
 		return Collections.unmodifiableList(new ArrayList<>(uniqueItems));
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/SpringApplicationTests.java

@@ -594,15 +594,14 @@ void addProfiles() {
 	}
 
 	@Test
-	void addProfilesOrder() {
+	void additionalProfilesOrderedBeforeActiveProfiles() {
 		SpringApplication application = new SpringApplication(ExampleConfig.class);
 		application.setWebApplicationType(WebApplicationType.NONE);
 		application.setAdditionalProfiles("foo");
 		ConfigurableEnvironment environment = new StandardEnvironment();
 		application.setEnvironment(environment);
 		this.context = application.run("--spring.profiles.active=bar,spam");
-		// Since Boot 2.4 additional should always be last
-		assertThat(environment.getActiveProfiles()).containsExactly("bar", "spam", "foo");
+		assertThat(environment.getActiveProfiles()).containsExactly("foo", "bar", "spam");
 	}
 
 	@Test

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ConfigDataEnvironmentPostProcessorIntegrationTests.java

@@ -308,7 +308,7 @@ void runWhenTwoProfilesSetProgrammaticallyLoadsWithPreservedProfileOrder() {
 	void runWhenProfilesPresentBeforeConfigFileProcessingAugmentsProfileActivatedByConfigFile() {
 		this.application.setAdditionalProfiles("other");
 		ConfigurableApplicationContext context = this.application.run("--spring.config.name=enableprofile");
-		assertThat(context.getEnvironment().getActiveProfiles()).containsExactly("myprofile", "other");
+		assertThat(context.getEnvironment().getActiveProfiles()).containsExactly("other", "myprofile");
 		String property = context.getEnvironment().getProperty("other.property");
 		assertThat(property).isEqualTo("fromotherpropertiesfile");
 		property = context.getEnvironment().getProperty("the.property");

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ProfilesTests.java

@@ -143,9 +143,9 @@ void getActiveWithProfileGroups() {
 	@Test
 	void getActiveWhenHasAdditionalIncludesAdditional() {
 		MockEnvironment environment = new MockEnvironment();
-		environment.setProperty("spring.profiles.active", "a,b,c");
+		environment.setProperty("spring.profiles.active", "d,e,f");
 		Binder binder = Binder.get(environment);
-		Profiles profiles = new Profiles(environment, binder, Arrays.asList("d", "e", "f"));
+		Profiles profiles = new Profiles(environment, binder, Arrays.asList("a", "b", "c"));
 		assertThat(profiles.getActive()).containsExactly("a", "b", "c", "d", "e", "f");
 	}