The amount of triangles drawn by the button depends on its `sizex`. See: ``` immBegin(GPU_PRIM_TRI_STRIP, (sizex + 1) * 2); ``` Therefore the `sizex` cannot be 0. Solution a bit similar to rB56b0cd1d. Ref T67671 Reviewers: fclem, brecht Maniphest Tasks: T67671 Differential Revision: https://developer.blender.org/D5347