Caret can disappear from script editor

[KoBeWi]

Tested versions

4.3 beta1

System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 31.0.15.4633) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

Issue description

Might be related to #90569

godot_cmbRAkzpFD.mp4

Seems to happen randomly. Also it's specific to the affected CodeEdit, as other scripts don't have the issue:

godot_zNqdxIHEMl.mp4

Steps to reproduce

1. 🤷‍♂️
2. Caret is not visible

Minimal reproduction project (MRP)

N/A

[Calinou]

If you disable caret blink in the script editor (either in the editor settings or by hacking around the editor source), does this still occur?

[KoBeWi]

Yes.

[jinyangcruise]

Same problem happens if text field in a standalone sub Window and in 4.3.dev6. But not happen in 4.3.beta1.
This is a MRP for this situation.

test_caret_blink_in_window.zip

Maybe it's not the same situation with KoBeWi's. But maybe related.

[Infini-Creation]

Got the same issue for a while (maybe from 4.3-dev5 release or a previous version), sometimes when renaming scene or script or even a directory, no caret at all. Pretty annoying.

[Calinou]

Same problem happens if text field in a standalone sub Window and in 4.3.dev6. But not happen in 4.3.beta1.
This is a MRP for this situation.

This may be due to an intentional check in the code that hides the caret for unfocused windows (like many operating systems tend to do on their native windows).

[KoBeWi]

I think this might be related to #92634