Fix this Metamorph crash when navigating with arrow keys into empty Chameleon section

Author: mchorse

gradle.properties

@@ -3,5 +3,5 @@ version=1.2.9
 mclib=2.3.1
 
 mc_version=1.12.2
-forge_version=14.23.2.2611
+forge_version=14.23.5.2799
 snapshot=snapshot_20171003

src/main/java/mchorse/metamorph/client/gui/GuiMorphs.java

@@ -14,6 +14,8 @@
 
 public class GuiMorphs extends GuiScrollElement
 {
+    private static final MorphCategory EMPTY_CATEGORY = new MorphCategory(null, null);
+
     /**
      * Cached previous filter. Used for avoiding double recalculations
      */
@@ -105,7 +107,7 @@ else if (y > 0 && this.isLastCategory(this.selected))
                 }
 
                 section = this.sections.get(sectionIndex);
-                category = section.section.categories.get(section.section.categories.size() - 1);
+                category = section.section.categories.isEmpty() ? EMPTY_CATEGORY : section.section.categories.get(section.section.categories.size() - 1);
             }
             else if (index >= section.section.categories.size())
             {
@@ -117,7 +119,7 @@ else if (index >= section.section.categories.size())
                 }
 
                 section = this.sections.get(sectionIndex);
-                category = section.section.categories.get(0);
+                category = section.section.categories.isEmpty() ? EMPTY_CATEGORY : section.section.categories.get(0);
             }
             else
             {