[bug #64308] [troff] should warn of negative arguments to \D'{c, e, E}' drawing commands

[G. Branden Robinson]

URL:
  <https://savannah.gnu.org/bugs/?64308>

                 Summary: [troff] should warn of negative arguments to
\D'{c,e,E}' drawing commands
                   Group: GNU roff
               Submitter: gbranden
               Submitted: Fri 16 Jun 2023 03:36:00 AM UTC
                Category: Core
                Severity: 3 - Normal
              Item Group: Warning/Suspicious behaviour
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None


    _______________________________________________________

Follow-up Comments:


-------------------------------------------------------
Date: Fri 16 Jun 2023 03:36:00 AM UTC By: G. Branden Robinson <gbranden>
It doesn't make any sense for a circle to have a negative diameter or an
ellipse to have axes of negative length.

Yet GNU troff accepts this and happily delivers this nonsense to output
drivers.

It should not.


$ groff -Z
\D'e -5 -2'
<Control+D>
x T ps
x res 72000 1 1
x init
p1
V12000
H72000
md
DFd
s10000
De -50000 -24000
n12000 0
x trailer
V792000
x stop
$ groff -Z
\D'c -10'
<Control+D>
x T ps
x res 72000 1 1
x init
p1
V12000
H72000
md
DFd
s10000
Dc -100000
n12000 0
x trailer
V792000
x stop









    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?64308>

_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/