Allow default profile to also be set in properties

Update `ConfigFileApplicationListener` so that active profiles set in
properties files that overlap with `spring.profiles.default` can still
be set.

Prior to this commit if `spring.profiles.active` happened to specify
a profile name that was also in `spring.profiles.default` it would
not get applied.

Fixes gh-6833

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

@@ -553,7 +553,7 @@ public class ConfigFileApplicationListener implements EnvironmentPostProcessor,
 		private void addProfiles(Set<Profile> profiles) {
 			for (Profile profile : profiles) {
 				this.profiles.add(profile);
-				if (!this.environment.acceptsProfiles(profile.getName())) {
+				if (!environmentHasActiveProfile(profile.getName())) {
 					// If it's already accepted we assume the order was set
 					// intentionally
 					prependProfile(this.environment, profile);
@@ -561,6 +561,15 @@ public class ConfigFileApplicationListener implements EnvironmentPostProcessor,
 			}
 		}
 
+		private boolean environmentHasActiveProfile(String profile) {
+			for (String activeProfile : this.environment.getActiveProfiles()) {
+				if (activeProfile.equals(profile)) {
+					return true;
+				}
+			}
+			return false;
+		}
+
 		private void prependProfile(ConfigurableEnvironment environment,
 				Profile profile) {
 			Set<String> profiles = new LinkedHashSet<String>();

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

@@ -824,7 +824,9 @@ public class ConfigFileApplicationListenerTests {
 		ConfigurableEnvironment environment = this.context.getEnvironment();
 		assertThat(environment.containsProperty("customprofile")).isTrue();
 		assertThat(environment.containsProperty("customprofile-specific")).isTrue();
-		assertThat(environment.containsProperty("customprofile-customdefault")).isFalse();
+		assertThat(environment.containsProperty("customprofile-customdefault")).isTrue();
+		assertThat(this.context.getEnvironment().acceptsProfiles("customdefault"))
+				.isTrue();
 	}
 
 	private Condition<ConfigurableEnvironment> matchingPropertySource(

spring-boot/src/test/resources/customprofile-customdefault.properties

+spring.profiles.include=specific
 customprofile-customdefault=true

spring-boot/src/test/resources/customprofile.properties

-spring.profiles.active=specific
+spring.profiles.active=customdefault
 customprofile=true