Responsive Preview: selecting "Desktop" when a custom canvas width is already wider than tablet does not set full width

[jordesign]

Description

When the canvas has been resized (using the draggable handles at the edges of the canvas) beyond tablet, the View menu shows Desktop as the selected viewport — but selecting "Desktop" from the menu doesn't snap the canvas back to its fullscreen default. The user has no way from the View menu to reset a widened canvas.

The View menu accurately reflects that Desktop is the current viewport intent, but its Desktop option isn't a "reset to fullscreen" action (as it is when in Tablet or Mobile view), so once the canvas has been widened the user has to drag the canvas edges back manually (or otherwise reset the width) to return to fullscreen.

7.1_responsive_desktop_toggle.mov

Steps to reproduce

1. Open a post or page in the editor.
2. Use the Preview button to select Tablet or Mobile viewport.
3. Drag the canvas edges to widen it beyond a standard viewport (past tablet width or into custom territory).
4. Open the View menu.
5. Observe that Desktop is already selected.
6. Click Desktop.

Expected

Selecting Desktop resets the canvas to its default fullscreen width. Alternatively, the View menu offers a distinct "Reset canvas" or "Fit to viewport" action.

Actual

Desktop is already selected and clicking it has no effect on the custom canvas width. The canvas remains at the user's dragged width with no in-menu way to reset it.

Reporter's own words

Desktop can't be reset/shown fullscreen from the View section when the custom canvas size exceeds tablet width.

Environment

• WordPress 7.1-beta4