[BlockData] Fix fromString no longer returning null when name is invalid

Signed-off-by: Irmo van den Berge <irmo.vandenberge@ziggo.nl>

src/main/java/com/bergerkiller/bukkit/common/wrappers/BlockDataRegistry.java

@@ -44,11 +44,16 @@ public class BlockDataRegistry {
      * Obtains immutable BlockData information wrapping particular IBlockData
      * 
      * @param iBlockData input data
-     * @return Immutable BlockData
+     * @return Immutable BlockData. Null if the input block data is null also.
      */
     public static BlockData fromBlockData(Object iBlockData) {
         final BlockDataWrapperHook hook = BlockDataWrapperHook.INSTANCE;
 
+        // Protect against null
+        if (iBlockData == null) {
+            return null;
+        }
+
         // Try to access an already hooked IBlockData first
         Object accessor;
         try {

src/test/java/com/bergerkiller/bukkit/common/BlockDataTest.java

@@ -358,6 +358,17 @@ public class BlockDataTest {
         assertEquals("furnace", blockData.getBlockName());
     }
 
+    @Test
+    public void testValidBlockDataFromString() {
+        assertEquals(MaterialUtil.getFirst("DIAMOND_BLOCK", "LEGACY_DIAMOND_BLOCK"),
+                BlockData.fromString("minecraft:diamond_block").getType());
+    }
+
+    @Test
+    public void testInvalidBlockDataFromString() {
+        assertNull(BlockData.fromString("invalid_block_data"));
+    }
+
     private void testSignMaterial(Material material, boolean isWallSign) {
         assertNotNull(material);
         BlockData signData = BlockData.fromMaterial(material);