In  Issue 828262  the implicit clearing code for WebGL is being improved to properly support using clearBufferfv to clear the color or depth buffer, clearBufferiv to clear the stencil buffer, and clearBufferfi to clear the depth and stencil buffers.

This code has some implicit assumptions that the color buffer's format is GL_RGB(A)8. With recent and somewhat experimental support for HDR, the color buffer might actually be 16-bit half-float. The code needs to be updated to work in this scenario.

There's another lurking problem in the code as currently written if the scissor test was enabled. This bug might be fixed in  Issue 828262 , but if not then that needs to be handled too: if the scissor test is enabled and the user calls e.g. clearBufferfv, we need to call ClearIfComposited for correctness before calling the real ClearBufferfv.