Adjusted some of the cycler code and added a test case for it.

- Added range checks for most blocks
- torches: Fixed cycle from 0->1->2->3->0 to 1->2->3->4->1
- mushroom caps: Included data value 10 (stem) in cycle
- vines: Included data value 0 (top attachment only) in the cycle
- furnaces/dispensers: Linearised the cycle. It's now 2->3->4->5->2
- chests/ladders: Added cycle code.
- rails: Linearised the cycle. It's now 6->7->8->9->6

src/main/java/com/sk89q/worldedit/data/BlockData.java

@@ -601,13 +601,15 @@ public final class BlockData {
         case BlockID.LONG_GRASS:
         case BlockID.STONE_BRICK:
         case BlockID.SILVERFISH_BLOCK:
+            if (data > 2) return -1;
             return (data + increment) % 3;
 
         case BlockID.TORCH:
         case BlockID.REDSTONE_TORCH_ON:
         case BlockID.REDSTONE_TORCH_OFF:
-            if (data == 5) return -1;
-            /* FALL-THROUGH */
+            if (data < 1 || data > 4) return -1;
+            return (data - 1 + increment) % 4 + 1;
+
         case BlockID.WOODEN_STAIRS:
         case BlockID.COBBLESTONE_STAIRS:
         case BlockID.BRICK_STAIRS:
@@ -615,64 +617,66 @@ public final class BlockData {
         case BlockID.PUMPKIN:
         case BlockID.JACKOLANTERN:
         case BlockID.TRAP_DOOR:
+            if (data > 3) return -1;
             return (data + increment) % 4;
 
         case BlockID.STEP:
         case BlockID.DOUBLE_STEP:
         case BlockID.CAKE_BLOCK:
+            if (data > 5) return -1;
             return (data + increment) % 6;
 
         case BlockID.CROPS:
         case BlockID.PUMPKIN_STEM:
         case BlockID.MELON_STEM:
+            if (data > 6) return -1;
             return (data + increment) % 7;
 
         case BlockID.SOIL:
         case BlockID.SNOW:
+            if (data > 8) return -1;
             return (data + increment) % 9;
 
         case BlockID.RED_MUSHROOM_CAP:
         case BlockID.BROWN_MUSHROOM_CAP:
-            return (data + increment) % 10;
+            if (data > 10) return -1;
+            return (data + increment) % 11;
 
         case BlockID.CACTUS:
         case BlockID.REED:
         case BlockID.SIGN_POST:
-            return (data + increment) % 16;
-
         case BlockID.VINE:
-            return (data - 1 + increment) % 15 + 1;
+            return (data + increment) % 16;
 
         case BlockID.FURNACE:
         case BlockID.BURNING_FURNACE:
         case BlockID.DISPENSER:
-            return (data + increment) % 4 + 2;
-
         case BlockID.WALL_SIGN:
-            return ((data + increment) - 2) % 4 + 2;
+        case BlockID.LADDER:
+        case BlockID.CHEST:
+            if (data < 2 || data > 5) return -1;
+            return (data - 2 + increment) % 4 + 2;
 
         case BlockID.REDSTONE_REPEATER_OFF:
-        case BlockID.REDSTONE_REPEATER_ON:
-            int dir = data & 0x3;
-            int delay = data & 0x0c;
-            return (dir + increment) % 4 | delay;
+        case BlockID.REDSTONE_REPEATER_ON: {
+            int orientation = data & 0x3;
+            int withoutOrientation = data & ~0x3;
+            return (orientation + increment) % 4 | withoutOrientation;
+        }
 
         case BlockID.MINECART_TRACKS:
-            if (data >= 6 && data <= 9) {
-                return (data + increment) % 4 + 6;
-            } else {
-                return -1;
-            }
+            if (data < 6 || data > 9) return -1;
+            return (data - 6 + increment) % 4 + 6;
 
         case BlockID.SAPLING:
-            int saplingType = data & 0x02;
-            int age = data & 0x0c;
-            return (saplingType + increment) % 3 | age;
+            int saplingType = data & 0x3;
+            int withoutType = data & ~0x3;
+            return (saplingType + increment) % 3 | withoutType;
 
         case BlockID.LEAVES:
-            int tree = data & 0x03;
-            int leafMeta = data & 0x0c;
-            return (tree + increment) % 4 | leafMeta;
+            int tree = data & 0x3;
+            int withoutTree = data & ~0x3;
+            return (tree + increment) % 4 | withoutTree;
 
         case BlockID.CLOTH:
             if (increment > 0) {
@@ -684,10 +688,11 @@ public final class BlockData {
             }
             return data;
 
-        case BlockID.FENCE_GATE:
-            int direction = data & 0x03;
-            int open = data & 0x04;
-            return (direction + increment) % 4 | open;
+        case BlockID.FENCE_GATE: {
+            int orientation = data & 0x3;
+            int withoutOrientation = data & ~0x3;
+            return (orientation + increment) % 4 | withoutOrientation;
+        }
 
         default:
             return -1;

src/test/java/com/sk89q/worldedit/data/BlockDataTest.java

@@ -22,12 +22,13 @@ package com.sk89q.worldedit.data;
 import org.junit.*;
 
 import com.sk89q.worldedit.CuboidClipboard.FlipDirection;
+import com.sk89q.worldedit.blocks.BlockID;
 
 import static org.junit.Assert.*;
 
 public class BlockDataTest {
     @Test
-    public void testSlice() {
+    public void testRotateFlip() {
         for (int type = 0; type < 256; ++type) {
             for (int data = 0; data < 16; ++data) {
                 final String message = type+"/"+data;
@@ -46,4 +47,24 @@ public class BlockDataTest {
             }
         }
     }
+
+    @Test
+    public void testCycle() {
+        for (int type = 0; type < 256; ++type) {
+            if (type == BlockID.CLOTH)
+                continue;
+
+            for (int data = 0; data < 16; ++data) {
+                final String message = type+"/"+data;
+
+                int cycled = BlockData.cycle(type, data, 1);
+
+                if (cycled <= data) {
+                    continue;
+                }
+
+                assertEquals(message, data+1, cycled); 
+            }
+        }
+    }
 }