Why is this an issue?

There is no reason to re-assign a variable to itself. Either this statement is redundant and should be removed, or the re-assignment is a mistake and some other value or variable was intended for the assignment instead.

Noncompliant code example

public void setName(String name) {
  name = name;
}

Compliant solution

public void setName(String name) {
  this.name = name;
}

Resources