Tidy test/prichunkpng
PATH=${PWD%code*}code:$PATH
-python -m pngsuite basn0g08 | prichunkpng - | file - | grep -q PNG
+# Null case for prichunkpng
+
+python -m pngsuite basn0g08 | prichunkpng - |
+ pripnglsch - |
+ grep -q IHDR
