In most places where pointer can be an 'error' it cannot be null
pointer. Further, in those cases just calling PTR_ERR() is not enough
to handle the null case. Simplify code by removing this case.
If NULL case needs to be handled, it's better to add separate check
and return fixed error code in that case.
- check magic field for 'ustar' on read
- harden get_octal to report errors on non-octal characters
(e.g. GNU base256 encoding), fixes#10757
- fix mtime and size octal fields to not have zero terminator
This moves and isolates the tar code to tar.c. And the actual
file extraction to disk is moved to extract.c.
A new API is introduced and used for v2 file extraction. This
essentially moves and isolates the apk_sign_ctx_* beast into
extract_v2.c and offers a saner interface to handling packages.
A place holder is added for v3 extraction.
ptrcnull