Fix handling of resources with trailing slashes

Fix #4326

Author: zakkak

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/Resources.java

@@ -29,7 +29,6 @@
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Enumeration;
@@ -43,7 +42,6 @@
 import org.graalvm.nativeimage.hosted.Feature;
 
 import com.oracle.svm.core.annotate.AutomaticFeature;
-import com.oracle.svm.core.jdk.resources.NativeImageResourcePath;
 import com.oracle.svm.core.jdk.resources.ResourceStorageEntry;
 import com.oracle.svm.core.util.ImageHeapMap;
 import com.oracle.svm.core.util.VMError;
@@ -85,9 +83,13 @@ public static byte[] inputStreamToByteArray(InputStream is) {
         }
     }
 
+    private static String getResourceWithoutTrailingSlash(String name) {
+        return name.endsWith("/") ? name.substring(0, name.length() - 1) : name;
+    }
+
     private static void addEntry(String moduleName, String resourceName, boolean isDirectory, byte[] data) {
         Resources support = singleton();
-        Pair<String, String> key = Pair.create(moduleName, resourceName);
+        Pair<String, String> key = Pair.create(moduleName, getResourceWithoutTrailingSlash(resourceName));
         ResourceStorageEntry entry = support.resources.get(key);
         if (entry == null) {
             entry = new ResourceStorageEntry(isDirectory);
@@ -121,21 +123,12 @@ public static void registerDirectoryResource(String moduleName, String resourceD
         addEntry(moduleName, resourceDirName, true, content.getBytes());
     }
 
-    /**
-     * Avoid pulling native file system by using {@link NativeImageResourcePath} implementation to
-     * convert <code>resourceName</code> to canonical variant.
-     */
-    public static String toCanonicalForm(String resourceName) {
-        NativeImageResourcePath path = new NativeImageResourcePath(null, resourceName.getBytes(StandardCharsets.UTF_8), true);
-        return new String(NativeImageResourcePath.getResolved(path));
-    }
-
     public static ResourceStorageEntry get(String name) {
-        return singleton().resources.get(Pair.createRight(name));
+        return singleton().resources.get(Pair.createRight(getResourceWithoutTrailingSlash(name)));
     }
 
     public static ResourceStorageEntry get(String moduleName, String resourceName) {
-        return singleton().resources.get(Pair.create(moduleName, resourceName));
+        return singleton().resources.get(Pair.create(moduleName, getResourceWithoutTrailingSlash(resourceName)));
     }
 
     private static URL createURL(String moduleName, String resourceName, int index) {
@@ -156,7 +149,7 @@ public static URL createURL(String moduleName, String resourceName) {
             return null;
         }
 
-        Enumeration<URL> urls = createURLs(moduleName, toCanonicalForm(resourceName));
+        Enumeration<URL> urls = createURLs(moduleName, resourceName);
         return urls.hasMoreElements() ? urls.nextElement() : null;
     }
 
@@ -170,7 +163,7 @@ public static InputStream createInputStream(String moduleName, String resourceNa
             return null;
         }
 
-        ResourceStorageEntry entry = Resources.get(moduleName, toCanonicalForm(resourceName));
+        ResourceStorageEntry entry = Resources.get(moduleName, getResourceWithoutTrailingSlash(resourceName));
         if (entry == null) {
             return null;
         }
@@ -186,33 +179,35 @@ public static Enumeration<URL> createURLs(String moduleName, String resourceName
         if (resourceName == null) {
             return null;
         }
-        String canonicalResourceName = toCanonicalForm(resourceName);
+        String resourceNameWithoutTrailingSlash = getResourceWithoutTrailingSlash(resourceName);
 
         List<URL> resourcesURLs = new ArrayList<>();
 
-        /* If moduleName was unspecified we have to consider all modules in the image */
+        ResourceStorageEntry explicitEntry = Resources.get(moduleName, resourceNameWithoutTrailingSlash);
+        addURLEntries(resourcesURLs, explicitEntry, moduleName, resourceName);
+        /* If moduleName was unspecified we have to consider all modules in the image
+         * We append those after the explicit entry in order to prioritize the explicit entry in case it exists
+         */
         if (moduleName == null) {
             for (Module module : BootModuleLayerSupport.instance().getBootLayer().modules()) {
-                ResourceStorageEntry entry = Resources.get(module.getName(), canonicalResourceName);
-                addURLEntries(resourcesURLs, entry, module.getName(), canonicalResourceName);
+                ResourceStorageEntry entry = Resources.get(module.getName(), resourceNameWithoutTrailingSlash);
+                addURLEntries(resourcesURLs, entry, module.getName(), resourceName);
             }
         }
-        ResourceStorageEntry explicitEntry = Resources.get(moduleName, canonicalResourceName);
-        addURLEntries(resourcesURLs, explicitEntry, moduleName, canonicalResourceName);
 
         if (resourcesURLs.isEmpty()) {
             return Collections.emptyEnumeration();
         }
         return Collections.enumeration(resourcesURLs);
     }
 
-    private static void addURLEntries(List<URL> resourcesURLs, ResourceStorageEntry entry, String moduleName, String canonicalResourceName) {
+    private static void addURLEntries(List<URL> resourcesURLs, ResourceStorageEntry entry, String moduleName, String resourceName) {
         if (entry == null) {
             return;
         }
         int numberOfResources = entry.getData().size();
         for (int index = 0; index < numberOfResources; index++) {
-            resourcesURLs.add(createURL(moduleName, canonicalResourceName, index));
+            resourcesURLs.add(createURL(moduleName, resourceName, index));
         }
     }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/resources/ResourceURLConnection.java

@@ -58,7 +58,7 @@ public void connect() {
             throw new IllegalArgumentException("Empty URL path not allowed in " + JavaNetSubstitutions.RESOURCE_PROTOCOL + " URL");
         }
         String resourceName = urlPath.substring(1);
-        ResourceStorageEntry entry = Resources.get(hostNameOrNull, Resources.toCanonicalForm(resourceName));
+        ResourceStorageEntry entry = Resources.get(hostNameOrNull, resourceName);
         if (entry != null) {
             List<byte[]> bytes = entry.getData();
             String urlRef = url.getRef();