Replace binder as contributors are processed

Update `ConfigDataEnvironment` so that the bootstrap `Binder` is
replaced as contributors are processed. The final `Binder` is now
also added without the `FAIL_ON_BIND_TO_INACTIVE_SOURCE` option so
that properties can be bound at the last stage even if values exist
in an inactive profile-specific document.

Closes gh-24669

Author: philwebb

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

@@ -22,7 +22,6 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
-import java.util.function.Supplier;
 
 import org.apache.commons.logging.Log;
 
@@ -107,6 +106,10 @@ class ConfigDataEnvironment {
 
 	private static final Bindable<List<String>> STRING_LIST = Bindable.listOf(String.class);
 
+	private static final BinderOption[] ALLOW_INACTIVE_BINDING = {};
+
+	private static final BinderOption[] DENY_INACTIVE_BINDING = { BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE };
+
 	private final DeferredLogFactory logFactory;
 
 	private final Log logger;
@@ -222,25 +225,22 @@ private ConfigDataEnvironmentContributor createInitialImportContributor(ConfigDa
 	void processAndApply() {
 		ConfigDataImporter importer = new ConfigDataImporter(this.logFactory, this.notFoundAction, this.resolvers,
 				this.loaders);
-		registerBootstrapBinder(() -> this.contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE));
+		registerBootstrapBinder(this.contributors, null, DENY_INACTIVE_BINDING);
 		ConfigDataEnvironmentContributors contributors = processInitial(this.contributors, importer);
-		Binder initialBinder = contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
-		registerBootstrapBinder(() -> initialBinder);
-		ConfigDataActivationContext activationContext = createActivationContext(initialBinder);
+		ConfigDataActivationContext activationContext = createActivationContext(
+				contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE));
 		contributors = processWithoutProfiles(contributors, importer, activationContext);
 		activationContext = withProfiles(contributors, activationContext);
 		contributors = processWithProfiles(contributors, importer, activationContext);
 		applyToEnvironment(contributors, activationContext);
 	}
 
-	private void registerBootstrapBinder(Supplier<Binder> supplier) {
-		this.bootstrapContext.register(Binder.class, InstanceSupplier.from(supplier).withScope(Scope.PROTOTYPE));
-	}
-
 	private ConfigDataEnvironmentContributors processInitial(ConfigDataEnvironmentContributors contributors,
 			ConfigDataImporter importer) {
 		this.logger.trace("Processing initial config data environment contributors without activation context");
-		return contributors.withProcessedImports(importer, null);
+		contributors = contributors.withProcessedImports(importer, null);
+		registerBootstrapBinder(contributors, null, DENY_INACTIVE_BINDING);
+		return contributors;
 	}
 
 	private ConfigDataActivationContext createActivationContext(Binder initialBinder) {
@@ -259,7 +259,9 @@ private ConfigDataActivationContext createActivationContext(Binder initialBinder
 	private ConfigDataEnvironmentContributors processWithoutProfiles(ConfigDataEnvironmentContributors contributors,
 			ConfigDataImporter importer, ConfigDataActivationContext activationContext) {
 		this.logger.trace("Processing config data environment contributors with initial activation context");
-		return contributors.withProcessedImports(importer, activationContext);
+		contributors = contributors.withProcessedImports(importer, activationContext);
+		registerBootstrapBinder(contributors, activationContext, DENY_INACTIVE_BINDING);
+		return contributors;
 	}
 
 	private ConfigDataActivationContext withProfiles(ConfigDataEnvironmentContributors contributors,
@@ -304,7 +306,15 @@ private Collection<? extends String> getIncludedProfiles(ConfigDataEnvironmentCo
 	private ConfigDataEnvironmentContributors processWithProfiles(ConfigDataEnvironmentContributors contributors,
 			ConfigDataImporter importer, ConfigDataActivationContext activationContext) {
 		this.logger.trace("Processing config data environment contributors with profile activation context");
-		return contributors.withProcessedImports(importer, activationContext);
+		contributors = contributors.withProcessedImports(importer, activationContext);
+		registerBootstrapBinder(contributors, activationContext, ALLOW_INACTIVE_BINDING);
+		return contributors;
+	}
+
+	private void registerBootstrapBinder(ConfigDataEnvironmentContributors contributors,
+			ConfigDataActivationContext activationContext, BinderOption... binderOptions) {
+		this.bootstrapContext.register(Binder.class, InstanceSupplier
+				.from(() -> contributors.getBinder(activationContext, binderOptions)).withScope(Scope.PROTOTYPE));
 	}
 
 	private void applyToEnvironment(ConfigDataEnvironmentContributors contributors,

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -51,6 +51,7 @@ void bootstrapsApplicationContext() {
 			LoaderHelper bean = context.getBean(TestConfigDataBootstrap.LoaderHelper.class);
 			assertThat(bean).isNotNull();
 			assertThat(bean.getBound()).isEqualTo("igotbound");
+			assertThat(bean.getProfileBound()).isEqualTo("igotprofilebound");
 			assertThat(bean.getLocation().getResolverHelper().getLocation())
 					.isEqualTo(ConfigDataLocation.of("testbootstrap:test"));
 		}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -121,6 +121,10 @@ String getBound() {
 			return this.binder.get().bind("myprop", String.class).orElse(null);
 		}
 
+		String getProfileBound() {
+			return this.binder.get().bind("myprofileprop", String.class).orElse(null);
+		}
+
 		@Override
 		public void onApplicationEvent(BootstrapContextClosedEvent event) {
 			event.getApplicationContext().getBeanFactory().registerSingleton("loaderHelper", this);

spring-boot-project/spring-boot/src/test/resources/application-bootstrap-registry-integration-tests.properties

@@ -1,2 +1,6 @@
 spring.config.import=testbootstrap:test
+spring.profiles.active=test
 myprop=igotbound
+#---
+spring.config.activate.on-profile=test
+myprofileprop=igotprofilebound