Backend initialization too early, causes --help to except if no backend found

[Sigurd Schneider]

Desired behaviour:
disper --help prints help and exits cleanly even if no backend is available

Observed behaviour:
disper --help excepts if no backend is available.

Propsed fix:
Delay backend initialization until switch has checked for --help arguments. See attached patch for details. The patch seems to work fine on my system.

More information:
The problem showed up when remaking disper.1.in: help2man wants to call disper, but fails because in the build environment no backend is available. Maybe there is a more generic way to get disper to print help even if no backend is available.

[wvengen (wvengen)]

Hi Sigurd, thanks for the bug report and the patch!
Your patch would work fine, but I'd like people to be able to user disper.switch_primary() directly as well, and then self.switcher would not yet be available. The issue is very much a valid one!

[Sigurd Schneider (sigurdschneider)]

I did not notice the dependency on switch_primary - so the patch is too simple. Anyway, thanks for taking the issue into consideration!

[wvengen (wvengen)]

would mind checking current bzr trunk works?

[Sigurd Schneider (sigurdschneider)]

That was fast, thanks! disper --help works without available backend, and switching displays works also works fine. (revno 115)

[wvengen (wvengen)]

Thanks for checking!