8344908: URLClassPath should not propagate IllegalArgumentException when finding resources in classpath URLs

Reviewed-by: alanb

src/java.base/share/classes/jdk/internal/loader/URLClassPath.java

@@ -903,7 +903,11 @@ public class URLClassPath {
         private FileLoader(URL url) throws IOException {
             super(url);
             String path = url.getFile().replace('/', File.separatorChar);
-            path = ParseUtil.decode(path);
+            try {
+                path = ParseUtil.decode(path);
+            } catch (IllegalArgumentException iae) {
+                throw new IOException(iae);
+            }
             dir = (new File(path)).getCanonicalFile();
             @SuppressWarnings("deprecation")
             var _unused = normalizedBase = new URL(getBaseURL(), ".");

src/java.base/share/classes/sun/net/www/ParseUtil.java

@@ -171,6 +171,7 @@ public final class ParseUtil {
      * Returns a new String constructed from the specified String by replacing
      * the URL escape sequences and UTF8 encoding with the characters they
      * represent.
+     * @throws IllegalArgumentException if {@code s} could not be decoded
      */
     public static String decode(String s) {
         int n = s.length();