Drawing to canvas breaks scissor coordinates, even when not drawing to canvas
While working on my game (Santacid), I used Canvas + Shaders for a special effect and noticed serious offset/clipping issues when changing scissors coordinates (as a result of a window resize) to be something other than the size of the Canvas object. I half-fixed it in my game by disabling scissors in the level that was having issues, but then the rest of the game continued to have clipping problems even though no canvas drawing occurred.
The bad offset + clipping only occurs along the Y axis. See attached screenshot and .love file.
I noticed a similar defect had already been written up here, though it pertains to use of scissors inside of canvas drawing. This is about scissors outside of canvas drawing, after the canvas drawing has occurred.
When no canvas drawing is performed, the bug fixes itself when the scissor coordinates change. Because the only state being saved by this test .love is whether or not the canvas is enabled, it definitely looks like an issue with LOVE.