Fixed ResourceFileSystem on dedicated servers.

Of course getMetadata and ilk are client only. Of course.

src/main/java/li/cil/oc2/common/util/ResourceUtils.java

@@ -0,0 +1,41 @@
+package li.cil.oc2.common.util;
+
+import com.google.gson.JsonObject;
+import net.minecraft.resources.IResource;
+import net.minecraft.resources.IResourceManager;
+import net.minecraft.resources.data.IMetadataSectionSerializer;
+import net.minecraft.util.JSONUtils;
+import net.minecraft.util.ResourceLocation;
+
+import javax.annotation.Nullable;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+
+public final class ResourceUtils {
+    @Nullable
+    public static <T> T getMetadata(final IResourceManager manager, final ResourceLocation resourceLocation, final IMetadataSectionSerializer<T> serializer) throws IOException {
+        final ResourceLocation metadataLocation = new ResourceLocation(
+                resourceLocation.getNamespace(), resourceLocation.getNamespace() + ".mcmeta");
+        if (!manager.hasResource(metadataLocation)) {
+            return null;
+        }
+
+        try (final IResource metadataResource = manager.getResource(metadataLocation)) {
+            final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(metadataResource.getInputStream(), StandardCharsets.UTF_8));
+            final JsonObject metadataJson = JSONUtils.fromJson(bufferedReader);
+            if (metadataJson == null) {
+                return null;
+            }
+
+            final String sectionName = serializer.getSectionName();
+            if (!metadataJson.has(sectionName)) {
+                return null;
+            }
+
+            final JsonObject section = JSONUtils.getJsonObject(metadataJson, sectionName);
+            return serializer.deserialize(section);
+        }
+    }
+}

src/main/java/li/cil/oc2/common/vm/fs/ResourceFileSystem.java

@@ -3,6 +3,7 @@ package li.cil.oc2.common.vm.fs;
 import com.google.gson.JsonObject;
 import it.unimi.dsi.fastutil.objects.Object2LongArrayMap;
 import li.cil.oc2.common.Constants;
+import li.cil.oc2.common.util.ResourceUtils;
 import li.cil.sedna.fs.*;
 import net.minecraft.resources.IResource;
 import net.minecraft.resources.IResourceManager;
@@ -298,9 +299,10 @@ public final class ResourceFileSystem implements FileSystem {
             boolean isDirectory;
             boolean isExecutable;
             if (location != null) {
-                try (final IResource resource = resourceManager.getResource(location)) {
-                    // Successfully retrieved resource, meaning it's a file.
-                    final FileAttributesMetadataSection metadata = resource.getMetadata(FileAttributesMetadataSection.SERIALIZER);
+                try {
+                    // If we can successfully retrieved resource it's a file. Directories cause errors.
+                    resourceManager.getResource(location);
+                    final FileAttributesMetadataSection metadata = ResourceUtils.getMetadata(resourceManager, location, FileAttributesMetadataSection.SERIALIZER);
                     isExecutable = metadata != null && metadata.isExecutable();
                     isDirectory = false;
                 } catch (final IOException e) {