Hi Martin,

On 06.04.2020 10:24, Martin Rudalics wrote:
> +
> +      if (totalwidth != gwidth || totalheight != gheight)
> +	{

Speaking of this optimization, can we make it apply to 'resize-mode' 
child frames too?

I've been doing some testing, and in certain situations, the value 
'hide' actually seems more performant when the size doesn't need to be 
changed. This largely makes a difference when, at random times, the 
child frame takes ~100ms to resize (which corresponds to the value of 
x-wait-for-event-timeout).

The attached patch seems to help.