QApplication cannot switch displays at runtime

Customer ran into the issue described in QTBUG-128345 due to a need to switch the display set to QApplication at runtime. They have the need to change an X11 display during runtime without stopping their application. They also need to be able to switch from an X11 display to Offscreen display and back to an X11 display to cover their current functionality. Currently this functionality does not exist causing them to need to delete QApplication in order to change displays, which is causing their application to crash. Below describes their current flow

  Example Current flow:

• Set Initial X11 Display Name
• Create QApplication
• XOpenDisplay called

• Destroy QApplication
• XCloseDisplay called

• Change X11 Display Name
• Create QApplication
• XOpenDisplay called

• ...

  Desired flow:

• Set Initial X11 Display Name
• Create QApplication
• Set New X11 Display Name
• Switch Display in Current QApplication
• ...

The ideal outcome for the customer is providing the ability for them to replace the current X11 connection with a different one.