From 3b858edfa9edb2a439aeeebbcf8f460c31d3f888 Mon Sep 17 00:00:00 2001
From: Michael Cramer <michael@bigmichi1.de>
Date: Thu, 11 Dec 2014 10:24:24 +0100
Subject: [PATCH] Auto-configure for Thymeleaf conditionalcomments

Add auto-configuration for thymeleaf-extras-conditionalcomments which
allows parsing of conditional comments for IE.

Example:

	<!--[if lt IE 8]>
		<link rel="stylesheet" th:href="@{/styleIE.css}"
		type="text/css"/>
	<![endif]-->

Without this dialect all Thymeleaf attributes are ignored inside the
comment.

Fixes gh-2113
---
 spring-boot-autoconfigure/pom.xml                   |  5 +++++
 .../thymeleaf/ThymeleafAutoConfiguration.java       | 13 +++++++++++++
 spring-boot-dependencies/pom.xml                    |  6 ++++++
 3 files changed, 24 insertions(+)

diff --git a/spring-boot-autoconfigure/pom.xml b/spring-boot-autoconfigure/pom.xml
index 038d7dd2c5..887a37bdee 100644
--- a/spring-boot-autoconfigure/pom.xml
+++ b/spring-boot-autoconfigure/pom.xml
@@ -375,6 +375,11 @@
 			<artifactId>thymeleaf-extras-data-attribute</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.thymeleaf.extras</groupId>
+			<artifactId>thymeleaf-extras-conditionalcomments</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.thymeleaf.extras</groupId>
 			<artifactId>thymeleaf-extras-springsecurity3</artifactId>
diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
index 87e445a1ef..f0cc34e146 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
@@ -41,6 +41,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.util.Assert;
 import org.thymeleaf.dialect.IDialect;
+import org.thymeleaf.extras.conditionalcomments.dialect.ConditionalCommentsDialect;
 import org.thymeleaf.extras.springsecurity3.dialect.SpringSecurityDialect;
 import org.thymeleaf.spring4.SpringTemplateEngine;
 import org.thymeleaf.spring4.resourceresolver.SpringResourceResourceResolver;
@@ -163,6 +164,18 @@ public class ThymeleafAutoConfiguration {
 
 	}
 
+	@Configuration
+	@ConditionalOnClass(ConditionalCommentsDialect.class)
+	protected static class ThymeleafConditionalCommentsDialectConfiguration {
+
+		@Bean
+		@ConditionalOnMissingBean
+		public ConditionalCommentsDialect conditionalCommentsDialect() {
+			return new ConditionalCommentsDialect();
+		}
+
+	}
+
 	@Configuration
 	@ConditionalOnClass({ Servlet.class })
 	@ConditionalOnWebApplication
diff --git a/spring-boot-dependencies/pom.xml b/spring-boot-dependencies/pom.xml
index 59fee6eb9e..2abbfd7c1f 100644
--- a/spring-boot-dependencies/pom.xml
+++ b/spring-boot-dependencies/pom.xml
@@ -127,6 +127,7 @@
 		<sun-mail.version>${javax-mail.version}</sun-mail.version>
 		<thymeleaf.version>2.1.3.RELEASE</thymeleaf.version>
 		<thymeleaf-extras-springsecurity3.version>2.1.1.RELEASE</thymeleaf-extras-springsecurity3.version>
+		<thymeleaf-extras-conditionalcomments.version>2.1.1.RELEASE</thymeleaf-extras-conditionalcomments.version>
 		<thymeleaf-layout-dialect.version>1.2.7</thymeleaf-layout-dialect.version>
 		<thymeleaf-extras-data-attribute.version>1.3</thymeleaf-extras-data-attribute.version>
 		<tomcat.version>8.0.15</tomcat.version>
@@ -1404,6 +1405,11 @@
 				<artifactId>thymeleaf-spring4</artifactId>
 				<version>${thymeleaf.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.thymeleaf.extras</groupId>
+				<artifactId>thymeleaf-extras-conditionalcomments</artifactId>
+				<version>${thymeleaf-extras-conditionalcomments.version}</version>
+			</dependency>
 			<dependency>
 				<groupId>org.thymeleaf.extras</groupId>
 				<artifactId>thymeleaf-extras-springsecurity3</artifactId>