oauth2Login does not auto-redirect for XHR request

Fixes gh-6812

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OAuth2LoginConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -64,6 +64,7 @@ import org.springframework.security.web.util.matcher.AndRequestMatcher;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
 import org.springframework.security.web.util.matcher.NegatedRequestMatcher;
 import org.springframework.security.web.util.matcher.OrRequestMatcher;
+import org.springframework.security.web.util.matcher.RequestHeaderRequestMatcher;
 import org.springframework.security.web.util.matcher.RequestMatcher;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -604,8 +605,11 @@ public final class OAuth2LoginConfigurer<B extends HttpSecurityBuilder<B>> exten
 		RequestMatcher defaultLoginPageMatcher = new AndRequestMatcher(
 				new OrRequestMatcher(loginPageMatcher, faviconMatcher), defaultEntryPointMatcher);
 
+		RequestMatcher notXRequestedWith = new NegatedRequestMatcher(
+				new RequestHeaderRequestMatcher("X-Requested-With", "XMLHttpRequest"));
+
 		LinkedHashMap<RequestMatcher, AuthenticationEntryPoint> entryPoints = new LinkedHashMap<>();
-		entryPoints.put(new NegatedRequestMatcher(defaultLoginPageMatcher),
+		entryPoints.put(new AndRequestMatcher(notXRequestedWith, new NegatedRequestMatcher(defaultLoginPageMatcher)),
 				new LoginUrlAuthenticationEntryPoint(providerLoginPage));
 
 		DelegatingAuthenticationEntryPoint loginEntryPoint = new DelegatingAuthenticationEntryPoint(entryPoints);

config/src/test/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OAuth2LoginConfigurerTests.java

@@ -353,6 +353,21 @@ public class OAuth2LoginConfigurerTests {
 		assertThat(this.response.getRedirectedUrl()).matches("http://localhost/login");
 	}
 
+	// gh-6812
+	@Test
+	public void oauth2LoginWithOneClientConfiguredAndRequestXHRNotAuthenticatedThenDoesNotRedirectForAuthorization() throws Exception {
+		loadConfig(OAuth2LoginConfig.class);
+
+		String requestUri = "/";
+		this.request = new MockHttpServletRequest("GET", requestUri);
+		this.request.setServletPath(requestUri);
+		this.request.addHeader("X-Requested-With", "XMLHttpRequest");
+
+		this.springSecurityFilterChain.doFilter(this.request, this.response, this.filterChain);
+
+		assertThat(this.response.getRedirectedUrl()).doesNotMatch("http://localhost/oauth2/authorization/google");
+	}
+
 	@Test
 	public void oauth2LoginWithCustomLoginPageThenRedirectCustomLoginPage() throws Exception {
 		loadConfig(OAuth2LoginConfigCustomLoginPage.class);