Lars at the OSL

Try this in Linux: open Firefox on your local machine. Then open a terminal window and ssh to another machine using the -X option for X forwarding. On the remote machine, start Firefox. The behavior I get is so bizarre that it cannot be a bug — somehow this looks intentional. The Firefox process on the remote machine sits for a few moments and then dies. Then a new local Firefox window opens. WTF?

I thought I was going insane. The people at the OSL that I told about this thought I was insane. The Mozilla developers that I work with and tried to explain this to thought I was insane.

Some research shows this: the remote Firefox actually starts and communicates with the X server running on the local machine. The X server tells the remote Firefox that there is already a process called Firefox running. The remote Firefox then sends a message to the local one to open a new window and then the remote Firefox dies. This protects a user from creating too many instances of a Firefox process on their machine. Clever, huh? But totally WRONG and counterintuitive!

Apparently you can stop this behavior if you start the remote Firefox with the intuitively named “no-remote” switch. That prevents the remote Firefox from “connecting” to the local Firefox.

Sigh, there goes an hour of my life that I’d like to have back…