macOS System Print Dialog bypasses "Open in Preview" and "Save as PDF" in Thunderbird v152 (macOS Tahoe / Apple M4)

   * OS: macOS Tahoe 15.5.1 (26.5.1)
   * Hardware: Apple M4 (Silicon)
   * Thunderbird Version: 152 (Issue present) / 151 (Works perfectly)

  * Open an email in Thunderbird v152.
  * Select Print...
  * in the Print Dialog window, select "Print using the system dialog" 
  * The system print dialog is opened
  * Click the PDF dropdown and select "Open in Preview" or "Save as PDF".

  Result: The document is instantly printed on the physical printer instead of performing the macOS system action.

  * Tested with Thunderbird v151: The macOS system print dialog works perfectly as intended.
  * Upgraded to v152: The issue appears immediately and consistently.
  * All other applications (Safari, Chrome, Microsoft products, Apple Mail) work correctly 

Hello, I am experiencing a severe issue with the macOS system print dialog handling in Thunderbird, which started immediately after updating to version 152. '''Environment''' * OS: macOS Tahoe 15.5.1 (26.5.1) * Hardware: Apple M4 (Silicon) * Thunderbird Version: 152 (Issue present) / 151 (Works perfectly) '''Description of the problem:''' When I use the native macOS system print dialog within Thunderbird and select either "Open in Preview", Instead of opening the Preview app Thunderbird bypasses the command and immediately sends the document directly to the default physical printer. The same happens with "Save as PDF", the file-saving dialog is first presented, but after entering the filename the document is also sends to the default physical printer rather than being saved. '''Steps to reproduce:''' * Open an email in Thunderbird v152. * Select Print... * in the Print Dialog window, select "Print using the system dialog" * The system print dialog is opened * Click the PDF dropdown and select "Open in Preview" or "Save as PDF". '''Result''': The document is instantly printed on the physical printer instead of performing the macOS system action. Steps taken: * Tested with Thunderbird v151: The macOS system print dialog works perfectly as intended. * Upgraded to v152: The issue appears immediately and consistently. * All other applications (Safari, Chrome, Microsoft products, Apple Mail) work correctly This seems to be a serious regression in how Thunderbird v152 handles native macOS print system events and dialog actions on Apple Silicon / macOS Tahoe. Any help or a fix for this would be greatly appreciated. Best regards, Michel