Modify test for special files.

[Vadiml1024]

For some reason the test S_ISREG fails on regular files.
For example:
stat /usr/lib/cups/backend/snmp
File: /usr/lib/cups/backend/snmp
Size: 35120 Blocks: 72 IO Block: 4096 regular file
Device: fd01h/64769d Inode: 656159 Links: 2
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2022-06-28 10:10:02.242856283 +0000
Modify: 2020-04-24 14:37:14.000000000 +0000
Change: 2021-12-15 23:29:04.213415906 +0000
Birth: -

If the above file is stored in tar.gz the S_ISREG(archive_entry_mode(e)) returns FALSE!

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[vassilit]

Could you provide a sample .tar.gz containing such a file ?

[mattmart3]

I can reproduce it with a tar.gz archive containing hard links.

The issue is likely related to how libarchive handles hard links.

Details in issue #18.