Support implicit ports in MHSR.getRequestURL()

Prior to this commit, MockHttpServletRequest.getRequestURL() always
included the server port number in the reconstructed request URL, even
for implicit ports (i.e., 80 and 443) and negative ports.

MockHttpServletRequest.getRequestURL() now omits the port number when
reconstructing a URL that has an implicit or negative port.

Issue: SPR-9726

spring-test/src/test/java/org/springframework/mock/web/MockHttpServletRequestTests.java

@@ -193,6 +193,39 @@ public class MockHttpServletRequestTests {
 		assertEqualEnumerations(Collections.enumeration(preferredLocales), request.getLocales());
 	}
 
+	@Test
+	public void getRequestURL() {
+		request.setServerPort(8080);
+		request.setRequestURI("/path");
+		assertEquals("http://localhost:8080/path", request.getRequestURL().toString());
+
+		request.setScheme("https");
+		request.setServerName("example.com");
+		request.setServerPort(8443);
+		assertEquals("https://example.com:8443/path", request.getRequestURL().toString());
+	}
+
+	@Test
+	public void getRequestURLWithDefaults() {
+		StringBuffer requestURL = request.getRequestURL();
+		assertEquals("http://localhost", requestURL.toString());
+	}
+
+	@Test
+	public void getRequestURLWithDefaultsAndHttps() {
+		request.setScheme("https");
+		request.setServerPort(443);
+		StringBuffer requestURL = request.getRequestURL();
+		assertEquals("https://localhost", requestURL.toString());
+	}
+
+	@Test
+	public void getRequestURLWithNegativePort() {
+		request.setServerPort(-99);
+		StringBuffer requestURL = request.getRequestURL();
+		assertEquals("http://localhost", requestURL.toString());
+	}
+
 	private void assertEqualEnumerations(Enumeration<?> enum1, Enumeration<?> enum2) {
 		assertNotNull(enum1);
 		assertNotNull(enum2);