UI bug: unable to "clear" after output (cat, tail, less) a binary file

[vbouiller]

Hi!

Description

I was playing around with GPG an tried to output a public GPG key. Of course, this file being a binary file it should print garbage which Ghostty actually did as expected.
However, when executing the clear command afterwards, the window does not clear as expected, the cursor is moved up to the first line, and hitting Enter, of typing in commands replaces the previous output character's by the new output (not the whole line).

How to reproduce and mitigate

Reproduction

Caveat: After trying a few times, it seems like it's not reproducible 100% of the time. Happened 9/10 times for me.

1. Output a binary file (like a PGP key, a .dmg file) with cat, head, tail (all three tested)
   

2. Execute the clear command. Notice that the cursor is back to the first line, but the window didn't clear
   

3. Type in another command, and notice that for each line, only the characters of the new ouput are replaced, but the rest of the line is unchanged and still show the previous line's characters.
   

Mitigation

The only mitagation I've found without closing the window (and losing the env) is the following:

1. Open a new tab in the same window
   
2. Switch back to tab 1
   
3. Execute a clear
4. Back to step 1. if there're still some printed characters

Version and misc.

• macos: 15.1.1
• Ghostty:
  • version 1.0.1
  • build 8696
  • commit 3f7c3afa

[veltza]

You should use the reset command when your terminal is in an abnormal state.

[rhodes-b]

if you cant type the command, you should be able to right click and there will be a menu option for reset as well

[vbouiller]

Thanks! Do your comments imply this si not a bug?

[veltza]

When you output binary data to the standard output, your terminal may interpret some binary bytes as control sequences and put your terminal in a strange state. The same thing can happen when you echo random control sequences from your command line. So I'd say this isn't a bug, because if you accidentally put your terminal in a certain state or mode, it can behave strangely from the user's perspective. And in these cases, the reset is your best friend.

[vbouiller]

Yeah but this is not happening with Terminal.app with the same files 🤷‍♂️ Anyway, thanks for your help 😄

[rhodes-b]

Like stated binary files might have values that could be interpreted as some escape code

Ghostty does not ignore parsing any of these because it might happen to be a binary file (terminal.app might)

Terminal.app might not support those escape sequences either in that case it just ignores them since it doesnt understand it in the first place

[mitchellh]

As noted in the other comments, this is likely not a bug. I'm guessing the binary file put the terminal in a state such that clear was doing the right thing given the state. Without a reproduction we can't know for sure, but that is most likely the case.