Labels with tabs-only text don't allocate space

[tvanderstad]

Describe the bug
Labels with only tabs in their text don't allocate space e.g. don't affect the layout of subsequent labels. This is confusing because empty labels do affect the layout.

To Reproduce
Run the following app:

#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]

use eframe::egui;

struct MyApp {}

impl eframe::App for MyApp {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        let long_text = "long text\n".repeat(50);

        egui::CentralPanel::default().show(ctx, |ui| {
            ui.label("-----");
            ui.label(""); // rendered
            ui.label("-----");
            ui.label(" "); // rendered
            ui.label("-----");
            ui.label("\t "); // rendered
            ui.label("-----");
            ui.label("\t"); // NOT rendered
            ui.label("-----");
            ui.label("\t\t"); // NOT rendered
            ui.label("-----");
        });
    }
}

fn main() {
    eframe::run_native(
        "test",
        eframe::NativeOptions {
            drag_and_drop_support: true,
            initial_window_size: Some(egui::vec2(900.0, 600.0)),
            ..Default::default()
        },
        Box::new(|_cc: &eframe::CreationContext| Box::new(MyApp {})),
    )
    .unwrap();
}

Expected behavior
A series of labels with text "-----" spaced equally apart.

Screenshots

Desktop:

• OS: MacOS Ventura 13.3.1

Additional context
Building a markdown editor for github.com/lockbook/lockbook and not sure how I'm supposed to render tab characters

[StripedMonkey]

This appears to have been fixed in git by #3302

[emilk]

Trailing tab characters also messes up the text layout