In many compiled templates I see this instruction:

$context = array_intersect_key($context, $_parent) + $_parent;

Problem is that many times that variable at the very end of some method and it's never used:

Two quick questions:

• Is setting this variable needed ... or is this indeed a case of "unused variable" that we should optimize?
• If it's a truly unused variable ... should we care about it or will PHP itself remove this variable (and avoid computing its value) when optimizing code to generate the bytecode?

Thanks!