Debug spid loop

Author: WrathfulSpatula

FindAFactor/_find_a_factor.cpp

@@ -704,15 +704,16 @@ struct Factorizer {
       std::vector<size_t> nspids(spids);
       for (size_t rpi = 0U; rpi < spids.size(); ++rpi) {
         const size_t pi = spids.size() - (rpi + 1U);
-        const size_t& p = smoothPrimes[spids[pi]];
+        const size_t pid = spids[pi];
+        const size_t& p = smoothPrimes[pid];
         if (factor % p) {
           // Once a preamble factor is found not to be present,
           // there's no longer use trying for it on the next iteration.
           nspids.erase(nspids.begin() + pi);
           continue;
         }
         factor /= p;
-        vec.flip(pi);
+        vec.flip(pid);
         if (factor == 1U) {
           // The step is fully factored.
           // (This case is always reached.)