What happened?

I noticed a possible regression in one of my apps. I had some QSelects where the value labels would contain newline characters (\n). While I need a slot for the options in the dropdown menu, for the representation of the actually selected value I could just set the css white-space: pre-wrap on the QSelect. This would cause the css property
white-space-collapse: preserve to be set on all the nested elements.

What did you expect to happen?

Before (<= 2.18.0), setting white-space: pre-wrap (or any other value for that matter) would work and cause the selected value in the QSelect, if it contained \n characters, to render these as newlines, as white-space-collapse: preserve would be set on all elements including the relevant span.

Since 2.18.1, this behavior stopped working: most of the nested elements still have white-space-collapse: preserve, except the related span, which as white-space-collapse: collapse set.

Reproduction URL

https://jsfiddle.net/kLdf7qv5/22/

How to reproduce?

1. Go to the reproduction URL
2. Observe how the various inputs render differently

Note that switching Quasar versions (not possible afaik on jsfiddle) would show it works on quasar <= 2.18.0

Flavour

Quasar CLI with Vite (@quasar/cli | @quasar/app-vite)

Areas

Components (quasar)

Platforms/Browsers

Chrome

Quasar info output

Operating System - Windows_NT(10.0.19045) - win32/x64
NodeJs - 20.11.1

Global packages
  NPM - 10.2.4
  yarn - 1.22.22
  pnpm - 9.14.2
  bun - Not installed
  @quasar/cli - 2.4.1
  @quasar/icongenie - Not installed
  cordova - Not installed

Important local packages
  quasar - 2.18.0 -- Build high-performance VueJS user interfaces (SPA, PWA, SSR, Mobile and Desktop) in record time
  @quasar/app-vite - 2.2.0 -- Quasar Framework App CLI with Vite
  @quasar/extras - 1.16.17 -- Quasar Framework fonts, icons and animations
  eslint-plugin-quasar - Not installed
  vue - 3.5.13 -- The progressive JavaScript framework for building modern web UI.
  vue-router - 4.5.0
  pinia - 3.0.2 -- Intuitive, type safe and flexible Store for Vue
  vite - 5.4.18 -- Native-ESM powered web dev build tool
  vite-plugin-checker - Not installed
  eslint - 9.24.0 -- An AST-based pattern checker for JavaScript.
  esbuild - 0.25.0 -- An extremely fast JavaScript and CSS bundler and minifier.
  typescript - 5.8.3 -- TypeScript is a language for application scale JavaScript development
  workbox-build - 7.3.0 -- A module that integrates into your build process, helping you generate a manifest of local files that workbox-sw should precache.
  register-service-worker - 1.7.2 -- Script for registering service worker, with hooks
  electron - Not installed
  @electron/packager - Not installed
  electron-builder - Not installed
  @capacitor/core - Not installed
  @capacitor/cli - Not installed
  @capacitor/android - Not installed
  @capacitor/ios - Not installed

Quasar App Extensions
  @quasar/quasar-app-extension-testing-unit-vitest - 1.1.0 -- A Quasar App Extension for running tests with Vitest

Networking
  Host - G3H16G3
  vEthernet (Default Switch) - 172.26.80.1
  Wi-Fi - 10.14.12.4

Relevant log output

Additional context

I am however not sure if this was ever supported in the first place. It seems the passing of the properties down to the span is intentional, but I could be wrong. I just wanted to flag it: if it is unintentional, you might want to decide what to do with this. If it was intentional, good to know and I'll double-check my projects.

Given the version number it happened in (2.18.1) and the release notes, I would suspect the "regression" to have been caused by changes for #17875