V571. Recurring check. This condition was already verified in previous line.

The analyzer detected a potential error: one and the same condition is checked twice.

Consider two samples:

// Example N1:
if (A == B)
{
  if (A == B)
    ...
}

// Example N2:
if (A == B) {
} else {
  if (A == B)
    ...
}

In the first case, the second check "if (A==B)" is always true. In the second case, the second check is always false.

It is highly probable that this code has an error. For instance, a wrong variable name is used because of a misprint. This is the correct code:

// Example N1:
if (A == B)
{
  if (A == C)
    ...
}

// Example N2:
if (A == B) {
} else {
  if (A == C)
    ...
}

This diagnostic is classified as: