Avoid loading location list with errors if it's already loaded when "set autoread" is set.

[msdos]

First, thanks for this plugin. It's great.

Second, I don't know if this is really an issue, or just an improvement. Here it goes.

I have your plugin installed. Suppose I'm editing a file with some erros (warnings), and then I edit this same file elsewhere, and since "autoread" is set in my .vimrc, a location list is loaded on top and the original location list on the bottom is kept as well.

I don't know if this is possible, but here is the suggestion: if there's already a location list loaded, don't load it again. I'm dont know vimscript so well, I think you already do this checking, but it may be lost when "autoread" is run, so you cant detect if location list is loaded, so the script loads the location list with syntax errors on the top again.

[scrooloose]

I cant reproduce this right now so im closing off this issue.

If its still occurring then just post a comment and ill reopen it and try harder to reproduce.