Add setIgnoreDefaultModelOnRedirect support

Add a `spring.mvc.set-ignore-default-model-on-redirect` property to
allow RequestMappingHandlerAdapter.setIgnoreDefaultModelOnRedirect to
be easily customized and change the default value to 'true'.

Fixes gh-2018

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration.java

@@ -42,6 +42,7 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
 import org.springframework.core.convert.converter.Converter;
@@ -63,6 +64,7 @@ import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.LocaleResolver;
 import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.ViewResolver;
+import org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
@@ -70,6 +72,7 @@ import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupp
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.i18n.FixedLocaleResolver;
+import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
 import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
 import org.springframework.web.servlet.view.BeanNameViewResolver;
 import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;
@@ -128,7 +131,7 @@ public class WebMvcAutoConfiguration {
 	// Defined as a nested config to ensure WebMvcConfigurerAdapter is not read when not
 	// on the classpath
 	@Configuration
-	@EnableWebMvc
+	@Import(EnableWebMvcConfiguration.class)
 	@EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class })
 	public static class WebMvcAutoConfigurationAdapter extends WebMvcConfigurerAdapter {
 
@@ -322,4 +325,24 @@ public class WebMvcAutoConfiguration {
 
 	}
 
+	/**
+	 * Configuration equivalent to {@code @EnableWebMvc} but with extra
+	 * {@link WebMvcProperties} support.
+	 */
+	@Configuration
+	public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration {
+
+		@Autowired(required = false)
+		private WebMvcProperties mvcProperties;
+
+		@Bean
+		@Override
+		public RequestMappingHandlerAdapter requestMappingHandlerAdapter() {
+			RequestMappingHandlerAdapter adapter = super.requestMappingHandlerAdapter();
+			adapter.setIgnoreDefaultModelOnRedirect(this.mvcProperties == null ? true
+					: this.mvcProperties.isIgnoreDefaultModelOnRedirect());
+			return adapter;
+		}
+
+	}
 }

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java

@@ -43,6 +43,12 @@ public class WebMvcProperties {
 	 */
 	private String dateFormat;
 
+	/**
+	 * If the the content of the "default" model should be ignored during redirect
+	 * scenarios.
+	 */
+	private boolean ignoreDefaultModelOnRedirect = true;
+
 	public DefaultMessageCodesResolver.Format getMessageCodesResolverFormat() {
 		return this.messageCodesResolverFormat;
 	}
@@ -68,4 +74,11 @@ public class WebMvcProperties {
 		this.dateFormat = dateFormat;
 	}
 
+	public boolean isIgnoreDefaultModelOnRedirect() {
+		return this.ignoreDefaultModelOnRedirect;
+	}
+
+	public void setIgnoreDefaultModelOnRedirect(boolean ignoreDefaultModelOnRedirect) {
+		this.ignoreDefaultModelOnRedirect = ignoreDefaultModelOnRedirect;
+	}
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfigurationTests.java

@@ -45,6 +45,7 @@ import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.format.support.FormattingConversionService;
 import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.servlet.HandlerAdapter;
@@ -279,6 +280,34 @@ public class WebMvcAutoConfigurationTests {
 		return mappingLocations;
 	}
 
+	@Test
+	public void ignoreDefaultModelOnRedirectIsTrue() throws Exception {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext();
+		this.context.register(Config.class, WebMvcAutoConfiguration.class,
+				HttpMessageConvertersAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		RequestMappingHandlerAdapter adapter = this.context
+				.getBean(RequestMappingHandlerAdapter.class);
+		assertEquals(true,
+				ReflectionTestUtils.getField(adapter, "ignoreDefaultModelOnRedirect"));
+	}
+
+	@Test
+	public void overrideIgnoreDefaultModelOnRedirect() throws Exception {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.mvc.ignore-default-model-on-redirect:false");
+		this.context.register(Config.class, WebMvcAutoConfiguration.class,
+				HttpMessageConvertersAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		RequestMappingHandlerAdapter adapter = this.context
+				.getBean(RequestMappingHandlerAdapter.class);
+		assertEquals(false,
+				ReflectionTestUtils.getField(adapter, "ignoreDefaultModelOnRedirect"));
+	}
+
 	@Configuration
 	protected static class ViewConfig {
 

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -87,6 +87,7 @@ content into your application; rather pick only the properties that you need.
 	spring.mvc.locale= # set fixed locale, e.g. en_UK
 	spring.mvc.date-format= # set fixed date format, e.g. dd/MM/yyyy
 	spring.mvc.message-codes-resolver-format= # PREFIX_ERROR_CODE / POSTFIX_ERROR_CODE
+	spring.mvc.ignore-default-model-on-redirect=true # If the the content of the "default" model should be ignored redirects
 	spring.view.prefix= # MVC view prefix
 	spring.view.suffix= # ... and suffix
 	spring.resources.cache-period= # cache timeouts in headers sent to browser