The analyzer has detected a case where a variable is assigned the value already stored in it. Such an assignment is very likely to be a logic error.
Consider the following example:
int i = foo();
if (i == 0)
{
i = 0; // <=
}
The reported assignment does not change the value of the variable, and the code is apparently faulty.
The analyzer can also detect cases where exact values of variables are unknown:
void foo(int x, int y)
{
if (x == y)
{
x = y; // <=
}
}
Even though the variables 'x' and 'y' can take any values, the assignment is still meaningless because of the earlier condition checking these variables for equality.