Funny action on "opening" a pdf document

[Theodore Kilgore <kilgota banach math auburn edu>]

I just did an update of my Slackware64-current system a few days ago. 
Today when I open a pdf file it starts to use xpdf (right, reasonable, and 
in accord with my previous practice). But for some weird reason it opens 
Firefox at the same time. I looked under Edit extension file and I found 

# PDF
type/^PDF
<------>Open=/usr/libexec/mc/ext.d/doc.sh open pdf
<------>View=%view{ascii} /usr/libexec/mc/ext.d/doc.sh view pdf

So then I looked at the doc.sh file and I found

do_open_action() {
    filetype=$1

    case "${filetype}" in
    ps)
        (gv "${MC_EXT_FILENAME}" &)
        ;;
    pdf)
        (xpdf "${MC_EXT_FILENAME}" &)
        #(acroread "${MC_EXT_FILENAME}" &)
        #(ghostview "${MC_EXT_FILENAME}" &)
        ;;

...(more entries)...
 
    esac
}

All looks innocent enough ...

But then at the bottom of the same file one sees

case "${action}" in
view)
    do_view_action "${filetype}"
    ;;
open)
    xdg-open "${MC_EXT_FILENAME}" 2>/dev/null || \
        do_open_action "${filetype}"
    ;;
*)
    ;;
esac

Then I do "man xdg-open" and I see this:

XDG-OPEN(1)                     xdg-open Manual                    
XDG-OPEN(1)

NAME
       xdg-open - opens a file or URL in the user's preferred application

SYNOPSIS
       xdg-open {file | URL}

       xdg-open {--help | --manual | --version}

DESCRIPTION
       xdg-open opens a file or URL in the user's preferred application. 
If a
       URL is provided the URL will be opened in the user's preferred web
       browser. If a file is provided the file will be opened in the 
preferred
       application for files of that type. xdg-open supports file, ftp, 
http
       and https URLs.

       xdg-open is for use inside a desktop session only. It is not
       recommended to use xdg-open as root.

etc. etc. 
----------------------------------------------------------------

So what seems to be happening is that the (purely local!) command to open 
a file which is on the hard drive of the local machine with an application 
which is on the local machine becomes an occasion for performing 
the purely extraneous act of opening a web browser in addition.

Weird. Also slightly irritating. I am using a desktop 
system at the moment, so it is only irritatint. But it is really not a 
very nice thing to do on a low-power machine like the Raspberry Pi which I 
am putting through its paces at home. On that or a similar hardware setup, 
this would not be funny, at all.

Does anyone know how to fix this?


----------------------------------------------------------------
kilgota banach:~$ mc -V
GNU Midnight Commander 4.8.4
Built with GLib 2.32.4
Using the S-Lang library with terminfo database
With builtin Editor
With subshell support as default
With support for background operations
With mouse support on xterm and Linux console
With support for X11 events
With internationalization support
With multiple codepages support
Virtual File Systems: cpiofs, tarfs, sfs, extfs, ftpfs, fish, smbfs
Data types: char: 8; int: 32; long: 64; void *: 64; size_t: 64; off_t: 64;
kilgota banach:~$ 

Theodore Kilgore