`uip` is always true

[Simon Felix]

PVS Studio (https://pvs-studio.com/en/order/for-students/#IDD159822EC6) found this potential problem.

The if statement on analyze.cpp:1186 is superfluous. uip must be non-zero because of the while loop on line 1093:

  uip = 0;
  while (!uip) {
    assert (i > 0);
    const int lit = (*t)[--i];
    if (!flags (lit).seen)
      continue;
    if (var (lit).level == level)
      uip = lit;
  }

https://github.com/arminbiere/cadical/blob/e7369b4b04fafe8b4b139d5e181528f5006d0816/src/analyze.cpp#L1186C4-L1186C4

[Armin Biere]

Looks like redundant indeed but not harmful.

[Armin Biere]

It is probably better to keep it as it is, since this function is pretty complex and somewhat defensive code is better in these cases.