Allow spring properties to be used in logback <if> blocks

Reorder `SpringBootJoranConfigurator.addModelHandlerAssociations` so
that handlers are added before calling the super method. Prior to this
commit, handlers were added behind filters which prevented them from
being used in `<if>` blocks.

Fixes gh-33028

spring-boot-project/spring-boot-parent/build.gradle

@@ -55,6 +55,13 @@ bom {
 			]
 		}
 	}
+	library("Janino", "3.1.8") {
+		group("org.codehaus.janino") {
+			imports = [
+				"janino"
+			]
+		}
+	}
 	library("JLine", "2.11") {
 		prohibit("[2.12,)") {
 			because "it contains breaking changes"

spring-boot-project/spring-boot/build.gradle

@@ -115,6 +115,7 @@ dependencies {
 	testImplementation("org.apache.derby:derby")
 	testImplementation("org.apache.derby:derbytools")
 	testImplementation("org.awaitility:awaitility")
+	testImplementation("org.codehaus.janino:janino")
 	testImplementation("org.eclipse.jetty:jetty-client")
 	testImplementation("org.eclipse.jetty.http2:http2-client")
 	testImplementation("org.eclipse.jetty.http2:http2-http-client-transport")

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/SpringBootJoranConfigurator.java

@@ -84,13 +84,13 @@ class SpringBootJoranConfigurator extends JoranConfigurator {
 
 	@Override
 	protected void addModelHandlerAssociations(DefaultProcessor defaultProcessor) {
-		super.addModelHandlerAssociations(defaultProcessor);
 		defaultProcessor.addHandler(SpringPropertyModel.class,
 				(handlerContext, handlerMic) -> new SpringPropertyModelHandler(this.context,
 						this.initializationContext.getEnvironment()));
 		defaultProcessor.addHandler(SpringProfileModel.class,
 				(handlerContext, handlerMic) -> new SpringProfileModelHandler(this.context,
 						this.initializationContext.getEnvironment()));
+		super.addModelHandlerAssociations(defaultProcessor);
 	}
 
 	@Override

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/SpringBootJoranConfiguratorTests.java

@@ -189,6 +189,20 @@ class SpringBootJoranConfiguratorTests {
 		assertThat(this.context.getProperty("MINE")).isEqualTo("bar");
 	}
 
+	@Test
+	void springPropertyInIfWhenTrue() throws Exception {
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.environment, "my.example-property=true");
+		initialize("property-in-if.xml");
+		assertThat(this.context.getProperty("MYCHECK")).isEqualTo("i-was-included");
+	}
+
+	@Test
+	void springPropertyInIfWhenFalse() throws Exception {
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.environment, "my.example-property=false");
+		initialize("property-in-if.xml");
+		assertThat(this.context.getProperty("MYCHECK")).isNull();
+	}
+
 	@Test
 	void addsAotContributionToContextDuringAotProcessing() throws Exception {
 		withSystemProperty("spring.aot.processing", "true", () -> {

spring-boot-project/spring-boot/src/test/resources/org/springframework/boot/logging/logback/property-in-if.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+	<include resource="org/springframework/boot/logging/logback/base.xml" />
+	<springProperty scope="context" name="MINE" source="my.example-property" />
+	<if condition='property("MINE").contains("true")'>
+		<then>
+			<variable scope="context" name="MYCHECK" value="i-was-included" />
+		</then>
+	</if>
+</configuration>