Prevent hanging when using older versions of tmux

[huzecong]

This pull request fixes issue #32 .

Using tmuxline with tmux 1.6 would cause vim to hang on startup. The code in question was https://github.com/edkolev/tmuxline.vim/blob/master/autoload/tmuxline.vim#L130:

call system("tmux source " . tmuxline#util#wrap_in_quotes(temp_file))

which in effect ran the following bash command:

(tmux source /tmp/xxxxx/0) >/tmp/xxxxx/1 2>&1

which causes bash to hang. But if tmux source ... is executed without the piping, it would return normally, and give a warning that one of the options was not available.

I don't know the exact reason behind this, but I tried changing the line of code into:

call system("tmux source " . tmuxline#util#wrap_in_quotes(temp_file) . " | cat")

and vim could start normally.

This sure is a rare problem (few would still use tmux 1.6 as of now), but I don't think adding a patch would hurt compatibility with other versions.

[kevinkjt2000]

Seems harmless enough to pipe to cat. I will go put this in my fork.