Check for empty instead of loose comparsion to 0
Check for empty instead of loose comparsion to 0

kkiernan/commonmark,colinodell/commonmark,thephpleague/commonmark,kkiernan/commonmark,fesor/commonmark,postalservice14/commonmark,fesor/commonmark,garethellis36/commonmark,postalservice14/commonmark,thephpleague/commonmark,garethellis36/commonmark