Bug 347874

OS: Windows 7 64-bit
CPU: AMD A8-6410 APU with AMD Radeon R5 Graphics (4 core), ~2.0GHz

When I have a canvas open on Krita, there is this small block that does not render.
The non-rendering spot (from now on will be referred to as "square") is not fixed on a specific point on the canvas, but instead seems to be on a fixed point relative to the window of the editing field.
However, the square only shows up on top of the canvas.  If the spot that the square would show up is off of the canvas, it won't show.

I believe it has to do with how the editing window is being rendered and nothing to do with the canvas at all.  The reason why I suspect this is because the transparency squares that shows within the "square" is smaller than the transparency squares shown from the canvas' alpha (when all the layers in a spot are invisible).

I was lucky enough to be able to catch a screenshot of said issue.  The image is uploaded at the URL posted.  You can see what I am talking about top-right from the center of the screen.  It always happens at the same spot no matter where the canvas is positioned on the window.

PLAUSIBLE CAUSES:
1.) My primary (and currently only) idea on what is causing this is data is somehow getting lost or not even calculated on that tile set.  It is always at the same spot and at the same size.
In fact, the exact position of the square is at 28, 7 in "square" units using OpenGL's coordinate system (top-left oriented instead of the typical bottom-left).  It isn't "exactly" that, but the offset on the x and the y are the same.
You can see an example of this at http://postimg.org/image/6gfncsga5/

If the issue's actual source is still unknown by Wednesday, I will download the source code and try to find the issue.  I really like what is being done here and I would very much like to contribute and see it succeed.


Reproducible: Always

Steps to Reproduce:
Simply load a canvas (either new or pre-existing) onto Krita.

Actual Results:  
(As Described Above)

Expected Results:  
For that transparency spot to not flash in and out.

I kind of already put all of my information that I find relevant in the Details section.