AbstractMockHttpServletRequestBuilder#buildRequest is not idempotent

Signed-off-by: Réda Housni Alaoui <reda-alaoui@hey.com>

Author: reda-alaoui

spring-test/src/main/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilder.java

@@ -898,16 +898,17 @@ private void updatePathRequestProperties(MockHttpServletRequest request, String
 		request.setContextPath(this.contextPath);
 		request.setServletPath(this.servletPath);
 
-		if ("".equals(this.pathInfo)) {
+		String pathInfoToUse = this.pathInfo;
+		if ("".equals(pathInfoToUse)) {
 			if (!requestUri.startsWith(this.contextPath + this.servletPath)) {
 				throw new IllegalArgumentException(
 						"Invalid servlet path [" + this.servletPath + "] for request URI [" + requestUri + "]");
 			}
 			String extraPath = requestUri.substring(this.contextPath.length() + this.servletPath.length());
-			this.pathInfo = (StringUtils.hasText(extraPath) ?
+			pathInfoToUse = (StringUtils.hasText(extraPath) ?
 					UrlPathHelper.defaultInstance.decodeRequestString(request, extraPath) : null);
 		}
-		request.setPathInfo(this.pathInfo);
+		request.setPathInfo(pathInfoToUse);
 	}
 
 	private void addRequestParams(MockHttpServletRequest request, MultiValueMap<String, String> map) {

spring-test/src/test/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilderTests.java

@@ -128,6 +128,14 @@ void mergeVersion() {
 		assertThat(buildRequest(builder).getHeader("API-Version")).isEqualTo("1.1");
 	}
 
+	@Test
+	void pathInfoIsNotMutatedByBuildMethod() {
+		TestRequestBuilder builder = new TestRequestBuilder(HttpMethod.GET).uri("/b");
+		assertThat(buildRequest(builder).getPathInfo()).isEqualTo("/b");
+		builder.uri("/a");
+		assertThat(buildRequest(builder).getPathInfo()).isEqualTo("/a");
+	}
+
 	private MockHttpServletRequest buildRequest(AbstractMockHttpServletRequestBuilder<?> builder) {
 		return builder.buildRequest(this.servletContext);
 	}