Additional fix with test cases for BZ 69623

Calls to ClassLoader.getResource().getContent() failed when made from
within a web application with resource caching enabled if the target
resource was packaged in a JAR file.
https://bz.apache.org/bugzilla/show_bug.cgi?id=69623

Author: markt-asf

java/org/apache/catalina/webresources/CachedResource.java

@@ -663,5 +663,10 @@ public JarFile getJarFile() throws IOException {
             return ((JarURLConnection) resourceURL.openConnection()).getJarFile();
         }
 
+        @Override
+        public String getContentType() {
+            // "content/unknown" is the value used by sun.net.www.URLConnection. It is used here for consistency.
+            return Objects.requireNonNullElse(getResource().getMimeType(), "content/unknown");
+        }
     }
 }

test/org/apache/catalina/loader/TestVirtualWebappLoader.java

@@ -86,7 +86,7 @@ public void testStartInternal() throws Exception {
 
         loader.start();
         String[] repos = loader.getLoaderRepositories();
-        Assert.assertEquals(5, repos.length);
+        Assert.assertEquals(6, repos.length);
         loader.stop();
 
         repos = loader.getLoaderRepositories();
@@ -95,7 +95,7 @@ public void testStartInternal() throws Exception {
         // no leak
         loader.start();
         repos = loader.getLoaderRepositories();
-        Assert.assertEquals(5, repos.length);
+        Assert.assertEquals(6, repos.length);
 
         // clear loader
         ctx.setLoader(null);

test/org/apache/catalina/webresources/TestCachedResource.java

@@ -16,6 +16,7 @@
  */
 package org.apache.catalina.webresources;
 
+import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.InputStream;
 import java.net.JarURLConnection;
@@ -131,4 +132,38 @@ public void testDirectoryListingsDir() throws Exception {
             Assert.assertNotNull(is);
         }
     }
+
+
+    @Test
+    public void testGetContentWebInfClasses() throws Exception {
+        Tomcat tomcat = getTomcatInstance();
+        File docBase = new File("test/webapp");
+        Context ctx = tomcat.addWebapp("/test", docBase.getAbsolutePath());
+        tomcat.start();
+
+        URL url = ctx.getLoader().getClassLoader().getResource("bug69623-a.mdd");
+        Object o = url.getContent();
+        /*
+         * Could test the actual content but a non-null return without an exception is enough to demonstrate the bug has
+         * not occurred.
+         */
+        Assert.assertTrue(o instanceof ByteArrayInputStream);
+    }
+
+
+    @Test
+    public void testGetContentWebInfLib() throws Exception {
+        Tomcat tomcat = getTomcatInstance();
+        File docBase = new File("test/webapp");
+        Context ctx = tomcat.addWebapp("/test", docBase.getAbsolutePath());
+        tomcat.start();
+
+        URL url = ctx.getLoader().getClassLoader().getResource("bug69623-b.mdd");
+        Object o = url.getContent();
+        /*
+         * Could test the actual content but a non-null return without an exception is enough to demonstrate the bug has
+         * not occurred.
+         */
+        Assert.assertTrue(o instanceof ByteArrayInputStream);
+    }
 }

test/webapp/WEB-INF/classes/bug69623-a.mdd

@@ -0,0 +1 @@
+This is a test file for https://bz.apache.org/bugzilla/show_bug.cgi?id=69623

test/webapp/WEB-INF/lib/bug69623-lib.jar

@@ -191,6 +191,12 @@
         to <code>true</code>. (markt)
       </update>
       <!-- Entries for backport and removal before 12.0.0-M1 below this line -->
+      <fix>
+        <bug>69623</bug>: Additional fix for the long standing regression that
+        meant that calls to <code>ClassLoader.getResource().getContent()</code>
+        failed when made from within a web application with resource caching
+        enabled if the target resource was packaged in a JAR file. (markt)
+      </fix>
     </changelog>
   </subsection>
   <subsection name="Coyote">