Fix crash with revolver in Battlegear slot (#16)

dependencies.gradle

@@ -4,6 +4,7 @@ dependencies {
     compile('thaumcraft:Thaumcraft:1.7.10-4.2.3.5:dev')
     compile('curse.maven:dummycore-230103:2244260')
     compile('com.github.GTNewHorizons:CodeChickenLib:1.1.5.3:dev')
+    runtime("com.github.GTNewHorizons:NotEnoughItems:2.2.6-GTNH:dev")
 
     runtime('com.github.GTNewHorizons:Baubles:1.0.1.14:dev')
     runtime('com.github.GTNewHorizons:CodeChickenCore:1.1.3:dev') // Required to allow dummycore to run in dev

src/main/java/tb/client/gui/GuiRevolver.java

@@ -1,5 +1,6 @@
 package tb.client.gui;
 
+import net.minecraft.entity.player.EntityPlayer;
 import org.lwjgl.opengl.GL11;
 
 import tb.common.inventory.ContainerRevolver;
@@ -43,8 +44,9 @@ protected void drawGuiContainerForegroundLayer(int mouseX, int mouseZ)
 
 	protected void drawGuiContainerBackgroundLayer(float partialTicks, int mouseX, int mouseZ)
 	{
-		 if (Minecraft.getMinecraft().thePlayer.inventory.mainInventory[this.blockedSlot] == null)
-			 Minecraft.getMinecraft().thePlayer.closeScreen();
+		EntityPlayer p = Minecraft.getMinecraft().thePlayer;
+		 if (p.inventory.mainInventory.length > this.blockedSlot && p.inventory.mainInventory[this.blockedSlot] == null)
+			 p.closeScreen();
 
 		 Minecraft.getMinecraft().renderEngine.bindTexture(revolverTextures);
 		 GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);