array_iter_base::advance Should Take a ssize_t

[nhusung]

I recently had an issue with Adiar, which uses TPIE. Running the example with clang’s undefined behavior sanitizer revealed unsigned overflows when computing offsets in the following method:

tpie/tpie/array.h

Line 56 in 663a261

void advance(size_t n) {if (forward) elm += n; else elm -= n;}

The overflow happens e.g. in case of n = (size_t) -1. Using ssize_t (i.e. the signed version of size_t) as argument seems to fix the issue.

[nhusung]

(I don’t know if this issue is related to my original problem, though.)