Normal record
a,b,c,d
EOL = CR+LF
a,b,c,d
EOL = CR+CR+LF
a,b,c,d
Quoted field
a,"b,c",d
Quote in quoted field
a,"b""c",d
Null fields
,a,b,,c,d,
Quoted null field, EOL = CR+LF
a,b,"",c,d
Embedded LF
a,"b
c",d
Embedded CR+LF and LF, EOL = CR+LF
"a
b","c
d"
Embedded plain CR, EOL = LR
a,b
c,d
No EOL at EOF
a,b,c,d