Fusion Mask Bypass Bug v19

I recently upgraded to v19.0.1 from v18.5 and when bypassing a mask that is placed on a merge node in Fusion, the entire background is displayed instead of the entire foreground. This is new to v19 and it did not used to do this before. The only way to bypass the mask properly is to disconnect it entirely from the merge, which is not convenient for quick toggling. Bypassing the mask should behave exactly the same as when it is not connected at all.

Here is a quick test with a white foreground over a blue background.
- Disconnecting the rectangle mask entirely shows the white foreground.
- Bypassing the rectangle mask shows the blue background.

Code: Select all

{
   Tools = ordered() {
      Rectangle1 = RectangleMask {
         CtrlWZoom = false,
         Inputs = {
            Filter = Input { Value = FuID { "Fast Gaussian" }, },
            MaskWidth = Input { Value = 1920, },
            MaskHeight = Input { Value = 1080, },
            PixelAspect = Input { Value = { 1, 1 }, },
            UseFrameFormatSettings = Input { Value = 1, },
            ClippingMode = Input { Value = FuID { "None" }, }
         },
         ViewInfo = OperatorInfo { Pos = { 660, 49.5 } },
      },
      white = Background {
         NameSet = true,
         Inputs = {
            GlobalOut = Input { Value = 25, },
            Width = Input { Value = 1920, },
            Height = Input { Value = 1080, },
            UseFrameFormatSettings = Input { Value = 1, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
            TopLeftRed = Input { Value = 1, },
            TopLeftGreen = Input { Value = 1, },
            TopLeftBlue = Input { Value = 1, }
         },
         ViewInfo = OperatorInfo { Pos = { 495, 82.5 } },
      },
      Merge1 = Merge {
         Inputs = {
            Background = Input {
               SourceOp = "blue",
               Source = "Output",
            },
            Foreground = Input {
               SourceOp = "white",
               Source = "Output",
            },
            PerformDepthMerge = Input { Value = 0, },
            EffectMask = Input {
               SourceOp = "Rectangle1",
               Source = "Mask",
            }
         },
         ViewInfo = OperatorInfo { Pos = { 660, 115.5 } },
      },
      MediaOut1 = MediaOut {
         Inputs = {
            Index = Input { Value = "0", },
            Input = Input {
               SourceOp = "Merge1",
               Source = "Output",
            }
         },
         ViewInfo = OperatorInfo { Pos = { 825, 115.5 } },
      },
      blue = Background {
         NameSet = true,
         Inputs = {
            GlobalOut = Input { Value = 25, },
            Width = Input { Value = 1920, },
            Height = Input { Value = 1080, },
            UseFrameFormatSettings = Input { Value = 1, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
            TopLeftGreen = Input { Value = 0.333333333333333, },
            TopLeftBlue = Input { Value = 0.498039215686275, }
         },
         ViewInfo = OperatorInfo { Pos = { 495, 115.5 } },
      }
   }
}


Yes, I'm seeing the same thing. I cannot recall if this was always like this or not, I haven't really paid attention, but I agree, it should show foreground as if the mask was detached. Possibly a bug.

I used to toggle masks on/off for comparison all the time in v18 and it definitely did not do this. I'm not sure how long it has been like this though as I didn't use any of the v19 beta versions. I noticed this problem right away when I switched to v19.0.1.