Program: 10315
Project: 10315
Buggy source:
/** 
 * Called when   {@link WorldClient#tick()} is called.<br/> Should be at end of the method.
 */
public static void onWorldClientTick(WorldClient sender){
  try {
    PROFILER.startSection("String_Node_Str");
    List<EntityPlayer> players=ImmutableList.copyOf(sender.playerEntities);
    if (sender != WDL.worldClient) {
      PROFILER.startSection("String_Node_Str");
      if (WDL.worldLoadingDeferred) {
        return;
      }
      WDLEvents.onWorldLoad(sender);
      PROFILER.endSection();
    }
 else {
      PROFILER.startSection("String_Node_Str");
      if (WDL.downloading && WDL.thePlayer != null) {
        if (WDL.thePlayer.openContainer != WDL.windowContainer) {
          if (WDL.thePlayer.openContainer == WDL.thePlayer.inventoryContainer) {
            boolean handled;
            PROFILER.startSection("String_Node_Str");
            PROFILER.startSection("String_Node_Str");
            handled=WDLEvents.onItemGuiClosed();
            PROFILER.endSection();
            Container container=WDL.thePlayer.openContainer;
            if (WDL.lastEntity != null) {
              Entity entity=WDL.lastEntity;
              for (              ModInfo<IGuiHooksListener> info : WDLApi.getImplementingExtensions(IGuiHooksListener.class)) {
                if (handled) {
                  break;
                }
                PROFILER.startSection(info.id);
                handled=info.mod.onEntityGuiClosed(sender,entity,container);
                PROFILER.endSection();
              }
              if (!handled) {
                WDLMessages.chatMessageTranslated(WDLMessageTypes.ON_GUI_CLOSED_WARNING,"String_Node_Str",entity);
              }
            }
 else {
              BlockPos pos=WDL.lastClickedBlock;
              for (              ModInfo<IGuiHooksListener> info : WDLApi.getImplementingExtensions(IGuiHooksListener.class)) {
                if (handled) {
                  break;
                }
                PROFILER.startSection(info.id);
                handled=info.mod.onBlockGuiClosed(sender,pos,container);
                PROFILER.endSection();
              }
              if (!handled) {
                WDLMessages.chatMessageTranslated(WDLMessageTypes.ON_GUI_CLOSED_WARNING,"String_Node_Str",pos,sender.getTileEntity(pos));
              }
            }
            PROFILER.endSection();
          }
 else {
            PROFILER.startSection("String_Node_Str");
            PROFILER.startSection("String_Node_Str");
            WDLEvents.onItemGuiOpened();
            PROFILER.endSection();
            PROFILER.endSection();
          }
          WDL.windowContainer=WDL.thePlayer.openContainer;
        }
      }
      PROFILER.endSection();
    }
    PROFILER.startSection("String_Node_Str");
    CapeHandler.onWorldTick(players);
    PROFILER.endSection();
    PROFILER.endSection();
  }
 catch (  Throwable e) {
    WDL.crashed(e,"String_Node_Str");
  }
}

Fixed version (ground truth):
/** 
 * Called when   {@link WorldClient#tick()} is called.<br/> Should be at end of the method.
 */
public static void onWorldClientTick(WorldClient sender){
  try {
    PROFILER.startSection("String_Node_Str");
    List<EntityPlayer> players=ImmutableList.copyOf(sender.playerEntities);
    if (sender != WDL.worldClient) {
      PROFILER.startSection("String_Node_Str");
      if (WDL.worldLoadingDeferred) {
        return;
      }
      WDLEvents.onWorldLoad(sender);
      PROFILER.endSection();
    }
 else {
      PROFILER.startSection("String_Node_Str");
      if (WDL.downloading && WDL.thePlayer != null) {
        if (WDL.thePlayer.openContainer != WDL.windowContainer) {
          if (WDL.thePlayer.openContainer == WDL.thePlayer.inventoryContainer) {
            boolean handled;
            PROFILER.startSection("String_Node_Str");
            PROFILER.startSection("String_Node_Str");
            handled=WDLEvents.onItemGuiClosed();
            PROFILER.endSection();
            Container container=WDL.thePlayer.openContainer;
            if (WDL.lastEntity != null) {
              Entity entity=WDL.lastEntity;
              for (              ModInfo<IGuiHooksListener> info : WDLApi.getImplementingExtensions(IGuiHooksListener.class)) {
                if (handled) {
                  break;
                }
                PROFILER.startSection(info.id);
                handled=info.mod.onEntityGuiClosed(sender,entity,container);
                PROFILER.endSection();
              }
              if (!handled) {
                WDLMessages.chatMessageTranslated(WDLMessageTypes.ON_GUI_CLOSED_WARNING,"String_Node_Str",entity);
              }
            }
 else {
              BlockPos pos=WDL.lastClickedBlock;
              for (              ModInfo<IGuiHooksListener> info : WDLApi.getImplementingExtensions(IGuiHooksListener.class)) {
                if (handled) {
                  break;
                }
                PROFILER.startSection(info.id);
                handled=info.mod.onBlockGuiClosed(sender,pos,container);
                PROFILER.endSection();
              }
              if (!handled) {
                WDLMessages.chatMessageTranslated(WDLMessageTypes.ON_GUI_CLOSED_WARNING,"String_Node_Str",pos,sender.getTileEntity(pos));
              }
            }
            PROFILER.endSection();
          }
 else {
            PROFILER.startSection("String_Node_Str");
            PROFILER.startSection("String_Node_Str");
            WDLEvents.onItemGuiOpened();
            PROFILER.endSection();
            PROFILER.endSection();
          }
          WDL.windowContainer=WDL.thePlayer.openContainer;
        }
      }
      PROFILER.endSection();
    }
    PROFILER.startSection("String_Node_Str");
    CapeHandler.onWorldTick(players);
    PROFILER.endSection();
    PROFILER.startSection("String_Node_Str");
    GuiTurningCameraBase.onWorldTick();
    PROFILER.endSection();
    PROFILER.endSection();
  }
 catch (  Throwable e) {
    WDL.crashed(e,"String_Node_Str");
  }
}