An image in a .ai's editing data whose operands had no matrix, fewer
than 11 numbers, or a matrix of other than six numbers was left out
with no warning. So was one whose matrix maps it onto a line or a
point. The reader's warnings did not mention such an image, while the
reader warned "an image VectorCraft can't read was left out" for an
image whose size or bit depth it can't use.
Each of those exits now adds the same warning, as does the one where
the decoded pixels don't make an image.