Meaning of level when reading

[reynir]

To me the meaning of the compatibility level argument when reading is unclear. It seems to only affect how the link indicator is deserialized:

ocaml-tar/lib/tar.ml

Lines 280 to 293 in fa05f16

	let of_char ?level =
	let level = get_level level in function
	| '1' -> Hard
	| '2' -> Symbolic
	| 'g' -> GlobalExtendedHeader
	| 'x' -> PerFileExtendedHeader
	| 'L' -> LongLink
	(* All other types returned as Normal in V7 for compatibility with older versions of ocaml-tar *)
	| _ when level = V7 -> Normal (* if value is malformed, treat as a normal file *)
	| '3' -> Character
	| '4' -> Block
	| '5' -> Directory
	| '6' -> FIFO
	| _ -> Normal (* if value is malformed, treat as a normal file *)

A few lines above that function a comment says V7 strictly speaking only supports Normal and Hard only.

ocaml-tar/lib/tar.ml

Lines 266 to 267 in fa05f16

	(* Strictly speaking, v7 supports Normal (as \0) and Hard only *)
	let to_char ?level =

To me, it seems that at least V7 and Ustar should not support GlobalExtendedHeader or PerFileExtendedHeader as they require Posix.

Since the reader is not very good at enforcing the compatibility level when reading perhaps this option should just be removed?

[reynir]

I discovered it is also used when deciding how to deal with link indicator types K and L (LongName and LongLink).

[hannesm]

This has been removed in #127