ID 208802 - Closing a Histogram tab results in black renders in Monitor tab

Problem summary

Closing the Histogram tab after use leaves the Monitor tab unable to display rendered images. Note that renders appear to be completing successfully, as can be seen in the Catalog tab or in the thumbnails of the Monitor tab. However, once a Monitor tab is in this state, there doesn't appear to be a way to return to normal functionality.

Steps to reproduce

1. Open a renderable Katana project and fire off a render. Once the render has completed, open a Histogram tab and use the pixel probe in the Monitor tab to select an array of pixels to display in the Histogram tab.

2. Now close the Histogram tab. Note that the Monitor tab's main render view is now black. Re-rendering will work, but will not be displayed in the Monitor tab. Moving the pixel probe on the now black Monitor will update the Histogram correctly.

Workaround

Setting the filmlook visualisation LUT to ‘None’ makes an image appear, albeit in the wrong colorspace.

Reproduced versions

The issue can be inconsistent to reproduce. It has been reproduced as far back as 2.1v2 -- the issue presumably goes back much further than this.

This issue is present in both Linux and Windows builds.

Expected behaviour

Closing the Histogram tab should not affect the Monitor’s ability to display images.

Actual behaviour

It does.