Blinking absorption heart textures do not appear to actually be used in-game

The bug

The textures absorbing_full_blinking.png, absorbing_half_blinking.png, absorbing_hardcore_full_blinking.png and absorbing_hardcore_half_blinking.png in the gui/sprites/hud/heart do nto appear to be used in-game when expected to, i.e. when taking damage or recovering health when under the effects of Absorption.

How to reproduce

A resource pack is attached to this ticket that switches the non-Hardcore textures for absorption hearts with the equivalent textures for frozen hearts.

To reproduce, take damage when under the effect of Absorption, or be at low health and gain the effect via a golden apple or other means and then recover health.

Expected results

With the resource pack active, the absorption hearts would turn pale blue when taking damage, etc.

Actual results

They are not.

How to fix

Making the absorption health bar blink when the player takes damage would probably fix this issue.