Re: [PATCH v2 2/2] read-cache: check range before dereferencing an array element

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> Before accessing an array element at a given index, we should make sure
> that the index is within the desired bounds, otherwise it makes little
> sense to access the array element in the first place.
> 
> In this instance, testing whether `ce->name[common]` is the trailing NUL
> byte is technically different from testing whether `common` is within
> the bounds of `previous_name`. It is also redundant, as the range-check
> guarantees that `previous_name->buf[common]` cannot be NUL and therefore
> the condition `ce->name[common] == previous_name->buf[common]` would not
> be met if `ce->name[common]` evaluated to NUL.
> 
> However, in the interest of reducing the cognitive load to reason about
> the correctness of this loop (so that I can focus on interesting
> projects again), I'll simply move the range-check to the beginning of
> the loop condition and keep the redundant NUL check.