Bug: GUNW/GOFF `mask` edge pixels mislabeled as water

[nemo794]

For GUNW and GOFF datasets, the mask layers are labeling the outer edge of the layer as water (100). I think this is a bug?

NOTE: This Issue is a follow-up to #224 . If the decision in #224 is to simply mark all geocoding fill as 255, then this Issue will be no longer relevant and can be closed.

[xhuang-jpl]

This is strange, can you point me the product? Thanks