For a long time, in some browsers/OSes there was a bug (or perhaps an archaic feature that was accidentally triggered) where the cursor in an input could get stuck and cause all new characters to be inserted to the left; I'm assuming it's related to that.

Notably this was a bug on the input for _setting_ your password, so if you think you've set Password123, you might have actually set 321drowassP, so even after fixing the bug it would still bite many users.

This is the first I've heard of it, and as a Linux user I feel like it's the kind of thing I'd either know about or experienced first-hand. What kind of system would do that? And "for a long time", like, you can't ever login anywhere, it's kind of obvious and breaking functionality badly, how can this exist for more than a single release if at all?

To be clear, it’s intermittent. Perhaps one in 500 times an input is focused, it exhibits this behavior.

I have experienced this so many times over my life with so many different hardware/software configurations, and I have to assume others have as well. It hasn’t happened in years but could explain why the “fix” described in the parent post was implemented.

This is in no way an educated guess, but it could be something about dealing with right-to-left language support?

The actual character bytes do not go end-to-start in RTL text, so I have a hard time seeing it'd be that. I have no better guess though.

But maybe humans were typing in reverse?

I could imagine having the left arrow key accidentally pressed (or stuck), but that's pretty niche