Quoth Jonathan Gray <jsg@jsg.id.au>:
> 
> Does any other shell use \O like this?
> 
> My preference is not to add more escape sequences.

Typos/style aside (I'll send a new patch if we get to
consensuus on the direction):

The typical methods of adding OSC7 support to your shell
look something like this:

	https://codeberg.org/dnkl/foot/wiki#user-content-how-to-configure-my-shell-to-emit-the-osc-7-escape-sequence

It's doable without shell support, but t seems quite clunky
to me.

The thing that make me think it's possibly sensible to
add support to the shell directly in some form is the
ugliness/fragility of doing url encoding in shell.

So, there are 3.5 options that we can pick from:

1) This patch, modulo cleanup
2) Doing this on cwd
	2.5) behind some knob, or unconditionally
3) Doing nothing, and using some external program
   or clunky chunk of shell.

I'm happy with either, though I may just carry a
patch forward for my own use if the consensus ends
up on option 3.