Bug 255749 – input[type="range"]: changing slot name while dragging thumb breaks interaction

• Component: DOM
• Status: RESOLVED CONFIGURATION CHANGED

If a custom element changes a slot name while an input[type="range"]'s thumb is being dragged and the pointer leaves the input, the interaction breaks as described below.

Reproduction: https://lit.dev/playground/#gist=710d6862ae3a2549ecb2b2d4a8663729

1. click the "Set slot name while dragging thumb" checkbox.
2. drag the range's thumb and move the pointer outside the input.

Expected: The thumb drags regardless of where the pointer is and stops dragging when the pointer is released.

Actual: The thumb stops dragging when the pointer moves outside the input; and if it's released while outside the input, when it is subsequently moved back to the input, the thumb starts dragging again even when the pointer is not down.

[Radar WebKit Bug Importer]

<rdar://problem/108628927>

[Ahmad Saleem]

(In reply to sorvell from comment #0)
> If a custom element changes a slot name while an input[type="range"]'s thumb
> is being dragged and the pointer leaves the input, the interaction breaks as
> described below.
> 
> Reproduction:
> https://lit.dev/playground/#gist=710d6862ae3a2549ecb2b2d4a8663729
> 
> 1. click the "Set slot name while dragging thumb" checkbox.
> 2. drag the range's thumb and move the pointer outside the input.
> 
> Expected: The thumb drags regardless of where the pointer is and stops
> dragging when the pointer is released.
> 
> Actual: The thumb stops dragging when the pointer moves outside the input;
> and if it's released while outside the input, when it is subsequently moved
> back to the input, the thumb starts dragging again even when the pointer is
> not down.

It seems to work fine now in WebKit ToT (263968@main). Appreciate if someone can also confirm, so we can close this.