Allow control characters from literal template text

[stanio]

Following:

• edcf3c8 (next #7711, v29.35.1)
• Regression: ANSI escape sequences not rendered anymore #7718

It is no longer possible to (effectively) specify literal (vs. dynamic/injected) control sequences in template text:

          "template": "\u001B[2 q", // reset to non-blinking block cursor

Can the control character filtering be limited just to injected variables vs. the full template result?

          "template": "{{ .Env.FOO }} \u001B[2 q",

I think such hard-coded text should be deemed safe, though I might be missing some edge case.

[JanDeDobbeleer]

It's not actually. This can also negatively influence the render (shell side). If you explain the use-case I could always add natively.

[stanio]

My use case is for working around:

• Add support for turning off cursor blink microsoft/terminal#1379

After exiting various editors (e.g. nvim, hx), they reset the cursors as if they output \u001B[0 q which makes Windows Terminal reset the cursor to blink. I would like to have the possibility of my prompt resetting the cursor to non-blinking state, like \u001B[?12l, or other specific cursor shape (\u001B[2 q, \u001B[4 q, \u001B[6 q).

I can imagine one may want to emit whatever other terminal control sequence directly, for any other reason of customization.

[stanio]

v30.5.0 works like a charm for me – thank you!

I'm using cursor_style: steady_block but I've noticed Windows Terminal provides Vintage (thick underscore), Double underscore (‗), and Empty box (▯) cursors that don't have specific DECSCUSR sequences, while ESC [ 0 SP q will reset to any of these, when configured. Blinking could be then controlled via ESC [ ? 12 l (disable) and ESC [ ? 12 h (enable). Maybe default_steady (ESC [ 0 SP q ESC [ ? 12 h) and default_blinking (ESC [ 0 SP q ESC [ ? 12 l) options could be added in future.

• https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences