bug#50237: 28.0.50; [calc] Default terminal when plotting in gnuplot without x11 support

[Ihor Radchenko <yantar92@gmail.com>]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> I was unable to reproduce the problem.
>
>> ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS HARFBUZZ IMAGEMAGICK JPEG
>> JSON LIBSELINUX LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY OLDXMENU
>> PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF X11 XDBE XIM XPM ZLIB
>
> I assume that the bug report was sent from a different Emacs, since this
> one has X11 support?  Can you give the `M-x report-emacs-bug' output
> from the Emacs that failed?  That should enable others to reproduce the
> issue.

Sorry, I was not clear enough. My Emacs is compiled with X11 support,
but my Gnuplot does not have X11 support. To reproduce, you need to
compile Gnuplot without X11 support.

The following is output of "set term" command in gnuplot. x11 terminal
is not there.

Available terminal types:
       cairolatex  LaTeX picture environment using graphicx package and Cairo backend
           canvas  HTML Canvas object
              cgm  Computer Graphics Metafile
          context  ConTeXt with MetaFun (for PDF documents)
          domterm  DomTerm terminal emulator with embedded SVG
             dumb  ascii art for anything that prints text
              dxf  dxf-file for AutoCad (default size 120x80)
              emf  Enhanced Metafile format
         epscairo  eps terminal based on cairo
         epslatex  LaTeX picture environment using graphicx package
              fig  FIG graphics language V3.2 for XFIG graphics editor
              gif  GIF images using libgd and TrueType fonts
             hpgl  HP7475 and relatives [number of pens] [eject]
             jpeg  JPEG images using libgd and TrueType fonts
               mf  Metafont plotting standard
               mp  MetaPost plotting standard
             pcl5  PCL5e/PCL5c printers using HP-GL/2
         pdfcairo  pdf terminal based on cairo
           pict2e  LaTeX2e picture environment
              png  PNG images using libgd and TrueType fonts
         pngcairo  png terminal based on cairo
       postscript  PostScript graphics, including EPSF embedded files (*.eps)
          pslatex  LaTeX picture environment with PostScript \specials
            pstex  plain TeX with PostScript \specials
         pstricks  LaTeX picture environment with PSTricks macros
               qt  Qt cross-platform interactive terminal
          sixelgd  sixel using libgd and TrueType fonts
              svg  W3C Scalable Vector Graphics
          tek40xx  Tektronix 4010 and others; most TEK emulators
          tek410x  Tektronix 4106, 4107, 4109 and 420X terminals
          texdraw  LaTeX texdraw environment
         tkcanvas  Tk canvas widget
          unknown  Unknown terminal type - not a plotting device
            vttek  VT-like tek40xx terminal emulator
            xterm  Xterm Tektronix 4014 Mode

Best,
Ihor