[An extra null pointer check is not needed](https://stackoverflow.com/questions/18775608/free-a-null-pointer-anyway-or-check-first "Free a null pointer anyway or check first?") in [the function “pdf_free_data”](https://github.com/PhilipHazel/pmw/blob/e007425ab34879aa7c11f8c16d8c689a21a5f52d/src/pdf.c#L2480 "Update candidate").
An extra null pointer check is not needed in the function “pdf_free_data”.