Support resource URL encoding at context path

Issue: SPR-13757

patch.txt

+diff --git a/spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilterTests.java b/spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilterTests.java
+index e94a2a6..5b67c58 100644
+--- a/spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilterTests.java
++++ b/spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilterTests.java
+@@ -89,6 +89,21 @@ public class ResourceUrlEncodingFilterTests {
+ 		});
+ 	}
+ 
++	// SPR-13757
++	@Test
++	public void encodeURLAtContextPath() throws Exception {
++		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/context");
++		request.setContextPath("/context");
++		request.setAttribute(ResourceUrlProviderExposingInterceptor.RESOURCE_URL_PROVIDER_ATTR, this.resourceUrlProvider);
++		MockHttpServletResponse response = new MockHttpServletResponse();
++
++		this.filter.doFilterInternal(request, response, (request1, response1) -> {
++			String result = ((HttpServletResponse) response1).encodeURL("/context/resources/bar.css");
++			assertEquals("/context/resources/bar-11e16cf79faee7ac698c805cf28248d2.css", result);
++		});
++	}
++
++
+ 	// SPR-13018
+ 	@Test
+ 	public void encodeEmptyURLWithContext() throws Exception {

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilter.java

@@ -95,6 +95,13 @@ public class ResourceUrlEncodingFilter extends OncePerRequestFilter {
 				String requestUri = urlProvider.getPathHelper().getRequestUri(this.request);
 				String lookupPath = urlProvider.getPathHelper().getLookupPathForRequest(this.request);
 				this.indexLookupPath = requestUri.lastIndexOf(lookupPath);
+
+				if ("/".equals(lookupPath) && !"/".equals(requestUri)) {
+					String contextPath = urlProvider.getPathHelper().getContextPath(this.request);
+					if (requestUri.equals(contextPath)) {
+						this.indexLookupPath = requestUri.length();
+					}
+				}
 			}
 		}
 

spring-webmvc/src/test/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilterTests.java

@@ -89,6 +89,33 @@ public class ResourceUrlEncodingFilterTests {
 		});
 	}
 
+	// SPR-13757
+	@Test
+	public void encodeContextPathUrlWithoutSuffix() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/context");
+		request.setContextPath("/context");
+		request.setAttribute(ResourceUrlProviderExposingInterceptor.RESOURCE_URL_PROVIDER_ATTR, this.resourceUrlProvider);
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		this.filter.doFilterInternal(request, response, (request1, response1) -> {
+			String result = ((HttpServletResponse) response1).encodeURL("/context/resources/bar.css");
+			assertEquals("/context/resources/bar-11e16cf79faee7ac698c805cf28248d2.css", result);
+		});
+	}
+
+	@Test
+	public void encodeContextPathUrlWithSuffix() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/context/");
+		request.setContextPath("/context");
+		request.setAttribute(ResourceUrlProviderExposingInterceptor.RESOURCE_URL_PROVIDER_ATTR, this.resourceUrlProvider);
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		this.filter.doFilterInternal(request, response, (request1, response1) -> {
+			String result = ((HttpServletResponse) response1).encodeURL("/context/resources/bar.css");
+			assertEquals("/context/resources/bar-11e16cf79faee7ac698c805cf28248d2.css", result);
+		});
+	}
+
 	// SPR-13018
 	@Test
 	public void encodeEmptyURLWithContext() throws Exception {