Problem Description

navigateToURL works only with Firefox with Linux. It ignores default selected web browser. Also it doesn't works if not installed Firefox.

Tested with multiple AIR versions, even with latest 51.2.2.5 with multiple different Ubuntu 22/24 devices (VM and physical, X11 and Wayland), with different applications and different default web browsers.
The same issue in all cases.

Related issues:
#4026
#3450
#3452
#3453
#3897
#1453

Steps to Reproduce

Test case 1:

1. Install Firefox (if it not installed).
2. Install Chrome web browser (or different) and make it default in OS system settings.
3. Launch application with code below and click anywhere on stage to open URL in default web browser.

Test case 2:

1. Uninstall Firefox (if it installed).
2. Install Chrome web browser (or different) and make it default in OS system settings.
3. Launch application with code below and click anywhere on stage to open URL in default web browser.

Application example with sources attached.
linux_navigatetourl_default_browser_bug.zip

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import flash.net.URLRequest;
	import flash.net.navigateToURL;
	
	public class LinuxNavigateToURLDefaultBrowserBug extends Sprite {
		
		public function LinuxNavigateToURLDefaultBrowserBug() {
			addEventListener(Event.ADDED_TO_STAGE, init);
		}
		
		private function init(e:Event):void {
			removeEventListener(Event.ADDED_TO_STAGE, init);
			
			stage.addEventListener(MouseEvent.CLICK, click);
		}
	
		private function click(e:MouseEvent):void {
			navigateToURL(new URLRequest("https://airsdk.harman.com/"));
		}
	}
}

Actual Result:
Test case 1:
URL will be opened in Firefox.

Test case 2:
Nothing happens.

Expected Result:
Test case 1:
URL will be opened in default system web browser (Chrome or which was set up).

Test case 2:
URL will be opened in default system web browser (Chrome or which was set up).

Known Workarounds

Launch via NativeProcess:
xdg-open https://airsdk.harman.com/