Size overflow for large images

[rdengate]

Imagine you have an inr file with dimensions 1500 x 1500 x 1500, which you are trying to read in, for mesh generation.

In ImageIO_impl.h, from line 1245, we have:

unsigned long size, nread;

if(im->openMode != OM_CLOSE) {
    size = im->xdim * im->ydim * im->zdim * im->vdim * im->wdim;

Let's say vdim is 1 and wdim is 2. Size should then be 6,750,000,000, but anything over 4,294,967,295 overflows. When the wrong value for size is used, the image is not read in correctly, which later results in an access violation exception.

If size_t (unsigned long long) is used for size instead of unsigned long, the value of size is stored correctly.

I propose changing this (in three places) in ImageIO_impl. If this is an acceptable solution, I'm happy to lodge a pull request.

[lrineau]

You are right. We would welcome a pull-request on that issue. Thanks @rdengate

[rdengate]

Thanks @lrineau. I have created a pull request, please see #7677.