A chain of ``if``/``else if`` statements is evaluated from top to bottom. At most, only one branch will be executed: the first one with a condition that evaluates to ``true``.
Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it's simply dead code and at worst, it's a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.
