Re: [Libguestfs] [PATCH nbdkit 2/2] common: Add checked-overflow macros and use for safe vector extension

How about: if (ADD_SIZE_T_OVERFLOW (v->cap, 1, &newcap) || ADD_SIZE_T_OVERFLOW (v->cap, newcap / 2, &newcap) || MUL_SIZE_T_OVERFLOW (newcap, itemsize, &newbytes) || newbytes < reqbytes) { /* If that either overflows or is less than the minimum requested, * fall back to the requested capacity. */ ... }