resize fails check50 for final sizes other than 4x4

Question

So after quite some fiddling I am at a place where, when resizing both small.bmp and smiley.bmp: 1) in- and out-files look the same; 2) peek matches the staff's implementation; and 3) "diff student.bmp staff bmp" returns no diferences. But, when running check50, resize correctly to some sizes but not others...

I am at a loss as I cannot figure where the error lies. I am providing a link to my code below. Any input will be greatly appreciated!

here's the updated link to the culprit code...

(Link updated... Thanks for pointing out the issue with the link!)

Answer 1

Found out that the issue had to do with calculating biSizeImage and bfSize independently and accounting for padding in one but not the other... thus, things matched when the output image had a size that was a multiple of 4 but not otherwise.

To anyone facing similar mixed results in check50, note the differences between how biSizeImage and bfSize are calculated in the broken code...