Mouse doesn't work unless xterm mode forced

[horkykuba]

Is there an existing issue for this?

• I have searched the existing issues

Midnight Commander version and build configuration

GNU Midnight Commander 4.8.33
Built with GLib 2.82.4
Built with S-Lang 2.3.3 with terminfo database
Built with libssh2 1.11.1
With builtin editor and aspell support
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
With ext2fs attributes support
Virtual File Systems:
 cpiofs, tarfs, sfs, extfs, ext2undelfs, ftpfs, sftpfs, shell
Data types:
 char: 8; int: 32; long: 64; void *: 64; size_t: 64; off_t: 64; uintmax_t: 64;

Operating system

Linux www 6.12.41+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.41-1 (2025-08-12) x86_64 GNU/Linux

Is this issue reproducible using the latest version of Midnight Commander?

• I confirm the issue is still reproducible with the latest version of Midnight Commander

How to reproduce

1. Use any terminal with mouse support excluding xterm mode hardcoded ones (xterm, alacritty, contour, dtterm, Eterm, foot, konsole, rxvt, screen, tmux), for example putty
2. Run mc (without -x command line option)
3. Mouse doesn't work

Expected behavior

mc should check kmous terminfo capability and enable mouse based on that.

Actual behavior

Mouse doesn't work. Hardcoding few terminals into code produces errorneous results.

Additional context

No response

[zyv]

@egmontkob, could you help out here? Is checking terminfo for mouse support desirable and easily implemented?

[egmontkob]

Use any terminal with mouse support excluding xterm mode hardcoded ones

The phrasing here is unclear to me. I guess the reporter refers to the value of $TERM, and whether that describes mouse support. E.g. currently with TERM=xterm-256color mouse works, but with TERM=putty-256color it doesn't although it should.

Is checking terminfo for mouse support desirable and easily implemented?

Yes, I believe so.

It looks to me that this is what tty_init_xterm_support() does, subject to is_xterm being true and thus entering the branch that will initialize use_mouse_p. However, with TERM=putty-256color, the is_xterm parameter is false.

This is inherited from the caller method tty_init(), to which mc_global.tty.xterm_flag is passed as this parameter. This value is set by tty_check_xterm_compat(), which compares TERM's string value against a list of known ones, excluding putty.

A quick workaround is to add putty here (I don't know what other consequences—good or bad—that would have), but ideally the whole situation should be revised. Such a hardcoded list is fine for situations where terminfo doesn't provide the necessary knowledge for us, but not where it does.

I don't know what else this xterm_flag is used for, but for mouse support I agree that we should eliminate its use and rely on terminfo's kmous.