set_color creates extra space

[rackodo]

set_color creates extra space

[zanchey]

Excitingly, this does not happen in git main at 4c1e25b, but the set_color invocation does not work quite right (eg echo What color is the date\? (set_color yellow; date +%T; set_color blue) has a blue date, not a yellow one).

[rackodo]

Weird... that's not what happens for me.

For reference, here's my fish_greeting.fish file.

function fish_greeting
    echo Hello friend!
    echo The time is (set_color yellow; date +%T; set_color blue) and this machine is called $hostname
end

(I know the text doesn't look blue, but that's what blue is in my palette.)

[zanchey]

Sorry, I see the behaviour you describe, but only on 3.6.4 and not in main, where it is different but also wrong.

[rackodo]

Is 3.6.4 not the latest release...? I tried upgrading fish (using Homebrew) but 3.6.4 is the latest version available. Or is main not the same?

[zanchey]

3.6.4 is the most recent release, but main includes a substantial port of the internals of fish, which has fixed some longstanding bugs but also introduced new ones.

[krobelus]

the color change bisects to ce559bc (cc @mqudsi)

[krobelus]

I've fixed the color.

The extra space happens because

$ echo (echo 1; set_color blue) 2

is equivalent(*) to

$ echo (echo 1; echo -n \e\[34m) 2

or

$ echo (echo 1\n\e\[34m) 2

fish trims trailing newlines from command substitution output.
There is no trailing newline here. echo will print both lines separated by a space. The second line is empty.

We could try to remove the last \n if it's followed by only invisible character sequences but that sounds confusing.
Probably best to work around it on your end

(*) found with

$ set_color blue | string escape
\e\[34m⏎

[zanchey]

Possibly we should fix the tutorial, but it's inelegant. echo The time is (set_color yellow)(date +%T)(set_color normal) now is the best I can do, but runs into our old friend Cartesian expansion if set_color produces no output.