Program: 10334
Project: 10334
Buggy source:
/** 
 * Adds the "Download this world" button to the ingame pause GUI.
 * @param gui
 * @param buttonList
 */
@SuppressWarnings({"String_Node_Str","String_Node_Str"}) public static void injectWDLButtons(GuiIngameMenu gui,List buttonList){
  int insertAtYPos=0;
  for (  Object obj : buttonList) {
    GuiButton btn=(GuiButton)obj;
    if (btn.id == 5) {
      insertAtYPos=btn.yPosition + 24;
      break;
    }
  }
  for (  Object obj : buttonList) {
    GuiButton btn=(GuiButton)obj;
    if (btn.yPosition >= insertAtYPos) {
      btn.yPosition+=24;
    }
  }
  GuiButton wdlDownload=new GuiButton(WDLs,gui.width / 2 - 100,insertAtYPos,170,20,null);
  GuiButton wdlOptions=new GuiButton(WDLo,gui.width / 2 + 71,insertAtYPos,28,20,I18n.format("String_Node_Str"));
  if (WDL.minecraft.isIntegratedServerRunning()) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
    wdlDownload.enabled=false;
  }
 else   if (!WDLPluginChannels.canDownloadAtAll()) {
    if (WDLPluginChannels.canRequestPermissions()) {
      wdlDownload.displayString=I18n.format("String_Node_Str");
    }
 else {
      wdlDownload.displayString=I18n.format("String_Node_Str");
      wdlDownload.enabled=false;
    }
  }
 else   if (WDL.saving) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
    wdlDownload.enabled=false;
    wdlOptions.enabled=false;
  }
 else   if (WDL.downloading) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
  }
 else {
    wdlDownload.displayString=I18n.format("String_Node_Str");
  }
  buttonList.add(wdlDownload);
  buttonList.add(wdlOptions);
}

Fixed version (ground truth):
/** 
 * Adds the "Download this world" button to the ingame pause GUI.
 * @param gui
 * @param buttonList
 */
@SuppressWarnings({"String_Node_Str","String_Node_Str"}) public static void injectWDLButtons(GuiIngameMenu gui,List buttonList){
  int insertAtYPos=0;
  for (  Object obj : buttonList) {
    GuiButton btn=(GuiButton)obj;
    if (btn.id == 5) {
      insertAtYPos=btn.y + 24;
      break;
    }
  }
  for (  Object obj : buttonList) {
    GuiButton btn=(GuiButton)obj;
    if (btn.y >= insertAtYPos) {
      btn.y+=24;
    }
  }
  GuiButton wdlDownload=new GuiButton(WDLs,gui.width / 2 - 100,insertAtYPos,170,20,null);
  GuiButton wdlOptions=new GuiButton(WDLo,gui.width / 2 + 71,insertAtYPos,28,20,I18n.format("String_Node_Str"));
  if (WDL.minecraft.isIntegratedServerRunning()) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
    wdlDownload.enabled=false;
  }
 else   if (!WDLPluginChannels.canDownloadAtAll()) {
    if (WDLPluginChannels.canRequestPermissions()) {
      wdlDownload.displayString=I18n.format("String_Node_Str");
    }
 else {
      wdlDownload.displayString=I18n.format("String_Node_Str");
      wdlDownload.enabled=false;
    }
  }
 else   if (WDL.saving) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
    wdlDownload.enabled=false;
    wdlOptions.enabled=false;
  }
 else   if (WDL.downloading) {
    wdlDownload.displayString=I18n.format("String_Node_Str");
  }
 else {
    wdlDownload.displayString=I18n.format("String_Node_Str");
  }
  buttonList.add(wdlDownload);
  buttonList.add(wdlOptions);
}