NULL is defined in stddef.h according to the C11 standard, so include it if it exists. opt is missing its data type so compilation of the code always fails. Fix it by adding int, the return type of getopt_long.
Coverage increased (+0.5%) to 77.314% when pulling 858a363ad2f03e165d0184bb05b4399751bcee84 on niclasr:fix-getopt_long-check into d4d2eccafb4fa658a2e77840ea52ca67a4f6248f on tbeu:master.
NULL is defined in stddef.h according to the C11 standard, so include it if it exists. opt is missing its data type so compilation of the code always fails. Fix it by adding int, the return type of getopt_long.