lib: revamp overflow checks in vec operations.

* lib.c (vector): Bugfix: we are checking whether
length + 2 is negative, not length. Check the original
value, and simplify everything using check_mulloc.
(list_vec, sub_vec): Use chk_xalloc just in case. There
shouldn't be any overflow if the vector was constructed and
manipulated properly.
(replace_vec): Replace division-based oveflow check with
a simple test that total + 2 doesn't overflow; then
rely on chk_xalloc to do the multiplication overflow
check.

0 files changed, 0 insertions, 0 deletions