Is the presentation engine allowed to perform queue family ownership transfers?

vkQueuePresentKHR says

> Presentation is a **read-only** operation that will not affect the content of the presentable images.

7.7.6. Queue Family Ownership Transfer says

> Queue family ownership transfers may perform read **and write** accesses on all memory bound to the image subresource or buffer range

The WSI and wayland compositors perform transitions to and from the foreign queue during presentation. While the WSI might have internal knowledge that this is a read-only operation, the wayland compositor does not.

Therefore it is unclear how the read-only requirement can be satisfied.

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As a side note: Wayland compositors also perform image layout transitions to shader-read-optimal and such, however, that can be worked around by always leaving the image in the general layout.

Start by comparing the vkQueuePresentKHR requirement with section 7.7.6, Queue Family Ownership Transfer. Review the described WSI and Wayland compositor transitions, including the note about shader-read-optimal layouts, and determine what clarification or specification change is needed so the read-only requirement is unambiguous.

Written by the indexing model from the issue text.