bound dilate and erode width to avoid mask-size overflow

[metsw24-max]

Unbounded dilate/erode width overflows the mask size

dilate() and erode() accept any positive integer, unlike the sibling median() which bounds its window to 1 to 1000, so an oversized width reaches the native Dilate/Erode where the structuring element is sized as 2 * width + 1 and passed to new_matrix; read through AttrAsUint32 into an int, a width of 2^30 wraps that signed size negative and 2^32 narrows it to zero, silently dropping the operation. Bounded the width to match median so the value can no longer reach that calculation.

[lovell]

Thanks for the PR to fix this. Is there a reason for the 1000 limit? I think it might need to be a bit higher than this, perhaps 65536 (1 << 16)?

[metsw24-max]

No strong reason for 1000, I just matched the bound median() uses for its window. 65536 is fine here. The only value that needs guarding is the 2 * width + 1 mask size, and at 65536 that comes to 131073, still well within int. Pushed a change bounding both to 1..65536.

[lovell]

Thank you