Mat-select - options with no value should not have selected state #11928
Description
Bug, feature request, or proposal:
The documentation recommends using an option with no value to reset the value of a mat-select. When a reset option is selected and you re-open the drop down, that option looks selected.
What is the expected behavior?
I would expect the "reset" options to be unselectable. At the least I would expect no styling after a reset option is selected.
What is the current behavior?
The "reset" option has the "selected" text color and background color.
What are the steps to reproduce?
The issue is present in the reset demo: https://material.angular.io/components/select/overview#resetting-the-select-value
What is the use-case or motivation for changing an existing behavior?
User confusion as to why the reset option "randomly" (from their perspective) changes color.
Which versions of Angular, Material, OS, TypeScript, browsers are affected?
Tested in Chrome and Firefox.