Inconsistent UI in Customizer > Navigaton

[kucrut]

On a new install or after activating a theme that supports menu locations, the menu dropdowns on the Navigation section have empty options selected, while — Select — should be selected instead.

[kucrut]

Use empty string as default option's value instead of 0.

[SergeyBiryukov]

30929.diff​ works as expected.

Any idea why it works without the patch on the Menus screen?

[kucrut]

Replying to SergeyBiryukov:

30929.diff​ works as expected.

Any idea why it works without the patch on the Menus screen?

I believe it's because on the Customizer screen, the option is actually selected by JS, while on the Menu Locations screen, the browser simply displays the first option (nothing is selected).

[SergeyBiryukov]

[31069] missed the ticket.