Fix servlet file listing

Fixes quarkusio#28028

extensions/undertow/deployment/src/test/java/io/quarkus/undertow/test/ResourceManagerTestCase.java

@@ -0,0 +1,59 @@
+package io.quarkus.undertow.test;
+
+import static org.hamcrest.Matchers.is;
+
+import java.io.IOException;
+import java.util.TreeSet;
+import java.util.stream.Collectors;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+import io.restassured.RestAssured;
+
+public class ResourceManagerTestCase {
+
+    private static final String CONTEXT_PATH = "/foo";
+    public static final String META_INF_RESOURCES = "META-INF/resources/";
+
+    @RegisterExtension
+    static QuarkusUnitTest runner = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClasses(ContextPathServlet.class)
+                    .addAsResource(new StringAsset("index.html"), "META-INF/resources/index.html")
+                    .addAsResource(new StringAsset("foo/foo.html"), "META-INF/resources/foo/foo.html")
+                    .addAsResource(new StringAsset("foo/bar/bar.html"), "META-INF/resources/foo/bar/bar.html"));
+
+    @Test
+    public void testServlet() {
+        RestAssured.when().get("/").then()
+                .statusCode(200)
+                .body(is("[foo, index.html]"));
+        RestAssured.when().get("/foo").then()
+                .statusCode(200)
+                .body(is("[foo/bar, foo/foo.html]"));
+        RestAssured.when().get("/foo/bar").then()
+                .statusCode(200)
+                .body(is("[foo/bar/bar.html]"));
+    }
+
+    @WebServlet(urlPatterns = "/*")
+    public static class ContextPathServlet extends HttpServlet {
+
+        @Override
+        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+            var paths = req.getServletContext().getResourcePaths(req.getPathInfo() == null ? "/" : req.getPathInfo());
+            resp.getWriter().write(String.valueOf(new TreeSet<>(
+                    paths.stream().map(s -> s.substring(s.lastIndexOf(META_INF_RESOURCES) + META_INF_RESOURCES.length()))
+                            .collect(Collectors.toSet()))));
+        }
+    }
+}

extensions/undertow/runtime/src/main/java/io/quarkus/undertow/runtime/KnownPathResourceManager.java

@@ -6,12 +6,12 @@
 import java.net.URL;
 import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
 import java.util.NavigableSet;
 import java.util.Set;
+import java.util.SortedSet;
 import java.util.TreeSet;
 
 import io.undertow.httpcore.OutputChannel;
@@ -24,7 +24,7 @@
 public class KnownPathResourceManager implements ResourceManager {
 
     private final NavigableSet<String> files;
-    private final Set<String> directories;
+    private final NavigableSet<String> directories;
     private final ResourceManager underlying;
 
     public KnownPathResourceManager(Set<String> files, Set<String> directories, ResourceManager underlying) {
@@ -51,7 +51,7 @@ public KnownPathResourceManager(Set<String> files, Set<String> directories, Reso
             tmp.add(i);
         }
         tmp.add("");
-        this.directories = Collections.unmodifiableSet(tmp);
+        this.directories = new TreeSet<>(tmp);
     }
 
     @Override
@@ -118,18 +118,36 @@ public boolean isDirectory() {
         @Override
         public List<Resource> list() {
             List<Resource> ret = new ArrayList<>();
-            String slashPath = path + "/";
-            for (String i : files.headSet(path)) {
-                if (i.startsWith(slashPath)) {
-                    try {
-                        ret.add(underlying.getResource(i));
-                    } catch (IOException e) {
-                        throw new RuntimeException(e);
+            String slashPath = path.isEmpty() ? path : path + "/";
+            SortedSet<String> fileSet;
+            SortedSet<String> dirSet;
+
+            fileSet = files.tailSet(slashPath);
+            dirSet = directories.tailSet(slashPath);
+            for (var s : List.of(fileSet, dirSet)) {
+                for (String i : s) {
+                    if (i.equals(slashPath)) {
+                        continue;
+                    }
+                    if (i.startsWith(slashPath)) {
+                        if (!i.substring(slashPath.length()).contains("/")) {
+                            try {
+                                Resource resource = underlying.getResource(i);
+                                if (resource == null) {
+                                    throw new RuntimeException("Unable to get listed resource " + i + " from directory " + path
+                                            + " for path " + slashPath + " from underlying manager " + underlying);
+                                }
+                                ret.add(resource);
+                            } catch (IOException e) {
+                                throw new RuntimeException(e);
+                            }
+                        }
+                    } else {
+                        break;
                     }
-                } else {
-                    break;
                 }
             }
+
             return ret;
         }