Currently, it's possible to change the listening socket for FvwmMFL via
an environment variable, FVWMMFL_SOCKET. The reasons for this is that it
makes it easier to move the socket path to different locations away from
/tmp, to, say, $FVWM_USERDIR.
However, this single environment variable is reused across different
running fvwm instances which means commands sent via FvwmPrompt or
FvwmCommand end up going to the wrong fvwm instance, as it's a case of
whichever process reads that first, is sent to the DISPLAY that fvwm is
running on.
Therefore, set FVWMMFL_SOCKET_PATH to a base directory, under which,
namespaced directories per DISPLAY for the relevant FvwmMFL sockets can
be created.
Currently, it's possible to change the listening socket for FvwmMFL via an environment variable, FVWMMFL_SOCKET. The reasons for this is that it makes it easier to move the socket path to different locations away from /tmp, to, say, $FVWM_USERDIR.
However, this single environment variable is reused across different running fvwm instances which means commands sent via FvwmPrompt or FvwmCommand end up going to the wrong fvwm instance, as it's a case of whichever process reads that first, is sent to the DISPLAY that fvwm is running on.
Therefore, set FVWMMFL_SOCKET_PATH to a base directory, under which, namespaced directories per DISPLAY for the relevant FvwmMFL sockets can be created.
Fixes #995