after linux Thunderbird upgrade to v. 68.2.2, email link opens firefox outside of sandbox
I'm running Antix 17 linux system on 32 bit system. After recent upgrade of Firefox (0.9.60-2) and Thunderbird (68.2.2), email links open a new instance of Firefox outside of Firejail sandbox, even when Firefox is already running in the sandbox. Before this upgrade, email links opened a new tab in the Firefox (already open). However, email link from Claws Mail does open a tab in running Firefox in sandbox.
The Thunderbird Preferences-Attachments- https line is set to use Firefox, the path shown is a symlink which should open Firefox in Firejail. The http line shows "please ask". With a link to http a dialogue box provides "use browser" option (opens new Firefox instance outside of sandbox). With a link to https, there is no dialogue box and Firefox opens outside of sandbox.
The default browser is Firefox in Firejail. From a terminal window, typing "firefox" opens Firefox inside Firejail sandbox. (The same occurs by typing the symlink path in terminal. So, I suspect that Thunderbird is not really going to the symlink, even though it appears to be set to do so.
What am I missing? Thanks in advance for your help.
Additional System Details
- User Agent: Mozilla/5.0 (X11; Linux i686; rv:68.0) Gecko/20100101 Firefox/68.0