bug#24125: 25.1.50; Docstring of gud-gdb

[Eli Zaretskii]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Date: Mon, 01 Aug 2016 19:31:06 +0200
> 
> The docstring of gud-gdb says:
> 
> (gud-gdb COMMAND-LINE)
> 
> Run gdb on program FILE in buffer *gud-FILE*.
> The directory containing FILE becomes the initial working
> directory and source-file directory for your debugger.
> 
> /end quote
> 
> There is no FILE in the argument list of the function, so this is
> confusing, moreover when gdb can be invoked without a program name (when
> attaching to a running process, for example.) It is not clear from the
> docstring if this case is supported.

Thanks fixed on the emacs-25 branch.