Guard against null spell HUD skins in all places, fixes #566

src/main/java/electroblob/wizardry/client/gui/GuiSpellDisplay.java

@@ -34,12 +34,13 @@ import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
 
+import javax.annotation.Nullable;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.*;
 import java.util.Map.Entry;
-import java.nio.charset.StandardCharsets;
 
 @Mod.EventBusSubscriber(Side.CLIENT)
 public class GuiSpellDisplay {
@@ -96,9 +97,28 @@ public class GuiSpellDisplay {
 		return Collections.unmodifiableMap(skins);
 	}
 	
-	/** Returns the skin that corresponds to the given key. */
+	/** Returns the skin that corresponds to the given key. If no such skin exists, returns the default skin as a
+	 * fallback. If the fallback skin is missing, prints a warning to the console and returns null. */
+	@Nullable
 	public static Skin getSkin(String key){
-		return skins.get(key);
+
+		Skin skin = skins.get(key);
+
+		if(skin == null){
+
+			Wizardry.logger.info("The spell HUD skin '" + Wizardry.settings.spellHUDSkin + "' specified in the config"
+					+ " did not match any of the loaded skins; using the default skin as a fallback.");
+
+			skin = skins.get(Settings.DEFAULT_HUD_SKIN_KEY);
+
+			if(skin == null){
+				Wizardry.logger.warn("The default spell HUD skin is missing! A resource pack must have overridden it"
+						+ " with an invalid JSON file (default.json), please try again without any resource packs.");
+				return null;
+			}
+		}
+
+		return skin;
 	}
 	
 	// Normally when extending Gui, you'd have to have an instance to access its methods. However, we're not actually
@@ -212,21 +232,9 @@ public class GuiSpellDisplay {
 			flipX = flipX == ((mainHand ? player.getPrimaryHand() : player.getPrimaryHand().opposite()) == EnumHandSide.LEFT);
 		}
 
-		Skin skin = skins.get(Wizardry.settings.spellHUDSkin);
+		Skin skin = getSkin(Wizardry.settings.spellHUDSkin);
 
-		if(skin == null){
+		if(skin == null) return; // Can't draw anything if there is no skin loaded!
-
-			Wizardry.logger.info("The spell HUD skin '" + Wizardry.settings.spellHUDSkin + "' specified in the config"
-					+ " did not match any of the loaded skins; using the default skin as a fallback.");
-
-			skin = skins.get(Settings.DEFAULT_HUD_SKIN_KEY);
-
-			if(skin == null){
-				Wizardry.logger.warn("The default spell HUD skin is missing! A resource pack must have overridden it"
-						+ " with an invalid JSON file (default.json), please try again without any resource packs.");
-				return;
-			}
-		}
 
 		GlStateManager.pushMatrix();
 

src/main/java/electroblob/wizardry/client/gui/config/GuiSelectHUDSkin.java

@@ -62,25 +62,28 @@ public class GuiSelectHUDSkin extends GuiSelectString {
 
 			Skin skin = GuiSpellDisplay.getSkin((String)this.currentValue);
 
-			float scale = Math.min((previewRight - previewLeft - 2*previewBorder)/(float)skin.getWidth(),
+			if(skin != null){
-									(previewBottom - previewTop - 2*previewBorder)/(float)skin.getHeight());
 
-			float x = (previewLeft + previewRight)/2f - (skin.getWidth()*scale)/2;
+				float scale = Math.min((previewRight - previewLeft - 2 * previewBorder) / (float)skin.getWidth(),
-			float y = (previewBottom + previewTop)/2f + (skin.getHeight()*scale)/2;
+						(previewBottom - previewTop - 2 * previewBorder) / (float)skin.getHeight());
 
-			GlStateManager.pushMatrix();
+				float x = (previewLeft + previewRight) / 2f - (skin.getWidth() * scale) / 2;
+				float y = (previewBottom + previewTop) / 2f + (skin.getHeight() * scale) / 2;
 
-			GlStateManager.scale(scale, scale, scale);
+				GlStateManager.pushMatrix();
 
-			skin.drawBackground((int)(x/scale), (int)(y/scale), false, false, 
+				GlStateManager.scale(scale, scale, scale);
-					Spells.magic_missile.getIcon(), 0.6f, false, false);
 
-			skin.drawText((int)(x/scale), (int)(y/scale), false, false, 
+				skin.drawBackground((int)(x / scale), (int)(y / scale), false, false,
-					Spells.none.getDisplayNameWithFormatting(),
+						Spells.magic_missile.getIcon(), 0.6f, false, false);
-					Spells.magic_missile.getDisplayNameWithFormatting(),
-					Spells.none.getDisplayNameWithFormatting(), 0);
 
-			GlStateManager.popMatrix();
+				skin.drawText((int)(x / scale), (int)(y / scale), false, false,
+						Spells.none.getDisplayNameWithFormatting(),
+						Spells.magic_missile.getDisplayNameWithFormatting(),
+						Spells.none.getDisplayNameWithFormatting(), 0);
+
+				GlStateManager.popMatrix();
+			}
 
 			Skin hovered = getHoveredSkin(mouseX, mouseY);