Fix signs displaying JSON text on Minecraft 1.21.5+

worldedit-core/src/legacy/java/com/sk89q/worldedit/blocks/SignBlock.java

@@ -45,8 +45,9 @@
 public class SignBlock extends LegacyBaseBlockWrapper {
 
     private String[] text;
+    private final int dataVersion;
 
-    private static final String EMPTY =  "{\"text\":\"\"}";
+    private static final String EMPTY_JSON = "{\"text\":\"\"}";
 
     /**
      * Construct the sign with text.
@@ -56,25 +57,37 @@ public class SignBlock extends LegacyBaseBlockWrapper {
      */
     public SignBlock(BlockState blockState, String[] text) {
         super(blockState);
+        this.dataVersion = WorldEdit.getInstance().getPlatformManager()
+                .queryCapability(Capability.WORLD_EDITING).getDataVersion();
         if (text == null) {
-            this.text = new String[]{EMPTY, EMPTY, EMPTY, EMPTY};
+            String empty = emptyText();
+            this.text = new String[]{empty, empty, empty, empty};
             return;
         }
-        for (int i = 0; i < text.length; i++) {
-            if (text[i].isEmpty()) {
-                text[i] = EMPTY;
-            } else {
-                text[i] = "{\"text\":" + GsonUtil.stringValue(text[i]) + "}";
+        if (usesJsonText()) {
+            for (int i = 0; i < text.length; i++) {
+                if (text[i].isEmpty()) {
+                    text[i] = EMPTY_JSON;
+                } else {
+                    text[i] = "{\"text\":" + GsonUtil.stringValue(text[i]) + "}";
+                }
             }
         }
         this.text = text;
     }
 
     private boolean isLegacy() {
-        int dataVersion = WorldEdit.getInstance().getPlatformManager().queryCapability(Capability.WORLD_EDITING).getDataVersion();
         return dataVersion < Constants.DATA_VERSION_MC_1_20;
     }
 
+    private boolean usesJsonText() {
+        return dataVersion < Constants.DATA_VERSION_MC_1_21_5;
+    }
+
+    private String emptyText() {
+        return usesJsonText() ? EMPTY_JSON : "";
+    }
+
     /**
      * Get the text.
      *
@@ -136,7 +149,8 @@ public void setNbtData(CompoundTag rootTag) {
 
         Tag<?, ?> t;
 
-        text = new String[]{EMPTY, EMPTY, EMPTY, EMPTY};
+        String empty = emptyText();
+        text = new String[]{empty, empty, empty, empty};
 
         t = values.get("id");
         if (!(t instanceof StringTag) || !((StringTag) t).getValue().equals(getNbtId())) {

worldedit-core/src/test/java/com/sk89q/worldedit/blocks/SignBlockTest.java

@@ -0,0 +1,144 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.blocks;
+
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.jnbt.ListTag;
+import com.sk89q.jnbt.StringTag;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.event.platform.PlatformsRegisteredEvent;
+import com.sk89q.worldedit.extension.platform.Capability;
+import com.sk89q.worldedit.extension.platform.Platform;
+import com.sk89q.worldedit.extension.platform.PlatformManager;
+import com.sk89q.worldedit.extension.platform.Preference;
+import com.sk89q.worldedit.internal.Constants;
+import com.sk89q.worldedit.util.test.ResourceLockKeys;
+import com.sk89q.worldedit.world.block.BlockState;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.parallel.ResourceLock;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+@ResourceLock(ResourceLockKeys.WORLDEDIT_PLATFORM)
+@SuppressWarnings("deprecation")
+class SignBlockTest {
+
+    private static final String EMPTY_JSON = "{\"text\":\"\"}";
+    private static final String HELLO_JSON = "{\"text\":\"Hello\"}";
+
+    private final AtomicInteger dataVersion = new AtomicInteger();
+    private final Platform platform = mock(Platform.class);
+
+    @BeforeEach
+    void setUpPlatform() {
+        when(platform.getCapabilities()).thenReturn(Map.of(Capability.WORLD_EDITING, Preference.PREFERRED));
+        when(platform.getDataVersion()).thenAnswer(__ -> dataVersion.get());
+        when(platform.getVersion()).thenReturn("test");
+
+        PlatformManager platformManager = WorldEdit.getInstance().getPlatformManager();
+        platformManager.register(platform);
+        WorldEdit.getInstance().getEventBus().post(new PlatformsRegisteredEvent());
+    }
+
+    @AfterEach
+    void tearDownPlatform() {
+        WorldEdit.getInstance().getPlatformManager().unregister(platform);
+    }
+
+    @Test
+    void usesJsonStringsBeforeMinecraft1215() {
+        dataVersion.set(Constants.DATA_VERSION_MC_1_21_4);
+
+        assertArrayEquals(
+                new String[]{EMPTY_JSON, HELLO_JSON, EMPTY_JSON, EMPTY_JSON},
+                messages(new SignBlock(mock(BlockState.class), new String[]{"", "Hello", "", ""}))
+        );
+        assertArrayEquals(
+                new String[]{EMPTY_JSON, EMPTY_JSON, EMPTY_JSON, EMPTY_JSON},
+                messages(new SignBlock(mock(BlockState.class), null))
+        );
+
+        SignBlock loadedSign = new SignBlock(mock(BlockState.class), null);
+        loadedSign.setNbtData(signNbt(HELLO_JSON));
+        assertArrayEquals(
+                new String[]{HELLO_JSON, EMPTY_JSON, EMPTY_JSON, EMPTY_JSON},
+                messages(loadedSign)
+        );
+    }
+
+    @ParameterizedTest
+    @ValueSource(ints = {
+            Constants.DATA_VERSION_MC_1_21_5,
+            Constants.DATA_VERSION_MC_1_21_10,
+            Constants.DATA_VERSION_MC_1_21_11,
+            Constants.DATA_VERSION_MC_26_1_2
+    })
+    void usesLiteralStringsFromMinecraft1215(int dataVersion) {
+        this.dataVersion.set(dataVersion);
+
+        assertArrayEquals(
+                new String[]{"", "Hello", "", ""},
+                messages(new SignBlock(mock(BlockState.class), new String[]{"", "Hello", "", ""}))
+        );
+        assertArrayEquals(
+                new String[]{"", "", "", ""},
+                messages(new SignBlock(mock(BlockState.class), null))
+        );
+
+        SignBlock loadedSign = new SignBlock(mock(BlockState.class), null);
+        loadedSign.setNbtData(signNbt("Hello"));
+        assertArrayEquals(
+                new String[]{"Hello", "", "", ""},
+                messages(loadedSign)
+        );
+    }
+
+    private static String[] messages(SignBlock sign) {
+        CompoundTag frontText = (CompoundTag) sign.getNbtData().getValue().get("front_text");
+        ListTag<?, ?> messages = frontText.getListTag("messages");
+        return messages.getValue().stream()
+                .map(StringTag.class::cast)
+                .map(StringTag::getValue)
+                .toArray(String[]::new);
+    }
+
+    private static CompoundTag signNbt(String... messages) {
+        return new CompoundTag(Map.of(
+                "id", new StringTag("minecraft:sign"),
+                "front_text", new CompoundTag(Map.of(
+                        "messages", new ListTag<>(
+                                StringTag.class,
+                                Arrays.stream(messages).map(StringTag::new).toList()
+                        )
+                ))
+        ));
+    }
+
+}