bin/60213: cat dumps dir list and glitchs tty font after using cat on a directory accidentaly (for ex. cat /); using NetBSD 11.0_RC3 (i386)

["c.santa%gmx.de@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60213
>Category:       bin
>Synopsis:       cat dumps dir list and glitchs tty font after using cat on a directory accidentaly (for ex. cat /); using NetBSD 11.0_RC3 (i386)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Apr 26 16:30:00 +0000 2026
>Originator:     Claus Santa
>Release:        
>Organization:
>Environment:
>Description:
Hello,

I think I have found a serious bug /bin/cat. I used cat on a directory by accident. This dumps the contentent of that directory and glitches the font of my TTY, which made it unreadable. For reproducing this bug yourself, for ex.:

cat /

Details:
version: NetBSD 11.0_RC3
arch: i386

This problem occours on all my devices: Akoya E1210 and EeePC 701. I do not have any 64bit cpmputer, thererfore I am not able to test this on this architecture too. But I think it's a bug in that programm, which doesn't check for it's arguments, if it's a file (or special file/block device) or a directory. I am not a programmer and switched recently staight from Windows to NetBSD (and love it).

Because I couldn't find any hint in the manpages and documentation about this issue I guess cat souldn't behave like this and it's a serious bug.

Best regards,
Santa
>How-To-Repeat:
cat / or any other directory
>Fix:
cat should check its arguments for beeing not a directory