bug#30208: M-x pdb breaks if certain characters are in the file's path

[Eli Zaretskii]

> From: Robin Allen <Robin.Allen@artsalliancemedia.com>
> Date: Mon, 22 Jan 2018 11:35:09 +0000
> 
> WORKAROUND
> This is caused by GUD choking on the @ character in the file path. I worked 
> around it by putting this in .emacs:
> (setq gud-pdb-marker-regexp
>   "^> \\([-a-zA-Z0-9_/.:\\@ 
> ]*\\|<string>\\)(\\([0-9]+\\))\\([a-zA-Z0-9_]*\\|\\?\\|<module>\\)()\\(->[^\n\r]*\\)?[\n\r]")
> 
> This is the default value, with @ (and space, for good measure) inserted in 
> the first group.

Thanks, I made that change.  But why did you need to escape the @
character?  It isn't a special character in Emacs regular expressions,
AFAIK.