Working draft

K06 symlink-named-dot

A symlink .: dropped, renamed, or an error?

Reject(draft) A strict parser must reject this archive.

Category
kind
Default policy
rejects it
Files
K06-symlink-named-dot.tar test archive, 3,072 bytes sha256 a02453579913af2146d9663d840b4ea2a0714ffc75d6e22c62e9fd9af597681a
K06-symlink-named-dot.jsonexpected result
K06-symlink-named-dot.txtannotated blocks
K06-symlink-named-dot.pygenerator script

The case

The archive has a directory d, then a symlink . to d, then a file f.

The special filename dot refers to the directory that it is in, so in POSIX a member . is the directory that the archive is extracted to. Creating a symlink there fails, as the name exists, which is an error. This case is ambiguous in practice because a reader can take the symlink in one of three ways. A reader that normalizes the name to the root drops the symlink, and extracts d and f. One that renames the member creates the symlink under another name, such as _. Other readers report an error.

Decision point: whether a link may have the name ..

Seen in: not measured, as the scans did not record the kind of a member .: 64 of the scanned tarballs have a member . or ./.

The archive

Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.

K06-symlink-named-dot: every block of the archive0x000000header: directoryname [0,100): "d" + 99 NULnamemode [100,108): "0000755" + NUL, 755 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000000" + NUL, 0mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007351\0 ", 3817: the unsigned sum of the header, this field as spacestypeflag [156,157): "5", directorylinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "d" + 99 NUL0x000200header: symlink, a symlink named .name [0,100): "." + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000000" + NUL, 0mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007421\0 ", 3857: the unsigned sum of the header, this field as spacestypeflag [156,157): "2", symlinklinkname [157,257): "d" + 99 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "." + 99 NULlinkname "d" + 99 NUL0x000400header: regular filename [0,100): "f" + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000002" + NUL, 2mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007345\0 ", 3813: the unsigned sum of the header, this field as spacestypeflag [156,157): "0", regular filelinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "f" + 99 NUL0x000600data2 bytes, then 510 NUL to the end of the block; "f\n""f\n"0x0008002 zero blocks: the end-of-archive markerbytes 0 to 512 of 1024: 512 NUL0x000a002 zero blocks, continuedbytes 512 to 1024 of 1024: 512 NUL0x000c00end of fileNULprintable ASCIIspacecontrol character, such as a newlinebyte over 0x7fwritten by the case itself
Every block, as text
K06-symlink-named-dot: must reject

A symlink `.`: dropped, renamed, or an error?

The archive has a directory `d`, then a symlink `.` to `d`, then a file `f`.

The special filename dot refers to the directory that it is in, so in POSIX a
member `.` is the directory that the archive is extracted to. Creating a symlink there fails, as
the name exists, which is an error. This case is ambiguous in
practice because a reader can take the symlink in one of three ways. A reader that normalizes the
name to the root drops the symlink, and extracts `d` and `f`. One that renames the member creates
the symlink under another name, such as `_`. Other readers report an error.

Decision point: whether a link may have the name `.`.
Seen in: not measured, as the scans did not record the kind of a member `.`: 64 of the scanned
tarballs have a member `.` or `./`.
See also: N05, a directory `./`.

0x000000  header: directory
          name     [  0,100)  "d" + 99 NUL
          mode     [100,108)  "0000755" + NUL  755 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000000" + NUL  0
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007351\0 "  3817: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "5"  directory
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000200  header: symlink, a symlink named .
          name     [  0,100)  "." + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000000" + NUL  0
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007421\0 "  3857: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "2"  symlink
          linkname [157,257)  "d" + 99 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000400  header: regular file
          name     [  0,100)  "f" + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000002" + NUL  2
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007345\0 "  3813: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "0"  regular file
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000600  data
          2 bytes, then 510 NUL to the end of the block
          "f\n"
0x000800  2 zero blocks: the end-of-archive marker
0x000c00  end of file
Every byte, as a hex dump

As xxd writes it: xxd -r makes the archive of it.

00000000: 6400 0000 0000 0000 0000 0000 0000 0000  d...............
00000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000060: 0000 0000 3030 3030 3735 3500 3030 3030  ....0000755.0000
00000070: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000080: 3030 3030 3030 3000 3030 3030 3030 3030  0000000.00000000
00000090: 3030 3000 3030 3733 3531 0020 3500 0000  000.007351. 5...
000000a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000100: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000120: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000130: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000140: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000150: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000200: 2e00 0000 0000 0000 0000 0000 0000 0000  ................
00000210: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000220: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000230: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000240: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000250: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000260: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000270: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000280: 3030 3030 3030 3000 3030 3030 3030 3030  0000000.00000000
00000290: 3030 3000 3030 3734 3231 0020 3264 0000  000.007421. 2d..
000002a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000300: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000310: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000320: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000330: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000340: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000350: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000360: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000370: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000380: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000390: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000400: 6600 0000 0000 0000 0000 0000 0000 0000  f...............
00000410: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000420: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000430: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000440: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000450: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000460: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000470: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000480: 3030 3030 3030 3200 3030 3030 3030 3030  0000002.00000000
00000490: 3030 3000 3030 3733 3435 0020 3000 0000  000.007345. 0...
000004a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000500: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000510: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000520: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000530: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000540: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000550: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000560: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000570: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000580: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000590: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000600: 660a 0000 0000 0000 0000 0000 0000 0000  f...............
00000610: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000620: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000630: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000640: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000650: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000660: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000670: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000680: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000690: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000700: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000710: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000720: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000730: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000740: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000750: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000760: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000770: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000780: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000790: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000800: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000810: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000820: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000830: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000840: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000850: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000860: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000870: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000880: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000890: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000008f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000900: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000910: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000920: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000930: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000940: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000950: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000960: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000970: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000980: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000990: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000009f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a00: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a10: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a20: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a30: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a40: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a50: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a60: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a70: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a80: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a90: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000aa0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000ab0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000ac0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000ad0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000ae0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000af0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b00: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b10: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b20: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b30: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b40: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b50: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b60: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b70: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b80: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b90: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000ba0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000bb0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000bc0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000bd0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000be0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000bf0: 0000 0000 0000 0000 0000 0000 0000 0000  ................

What implementations make of it

In the outcome column, ✅ means that the implementation follows the default policy.

implementationversionoutcomewhat it makes of it
GNU tartar (GNU tar) 1.35✅ rejectserror: tar: .: Cannot create symlink to ‘d’: File exists tar: Exiting with failure status due to previous errors
bsdtarbsdtar 3.8.11 - libarchive 3.8.11✅ rejectserror: .: Can't replace existing directory with non-directory: Invalid argument bsdtar: Error exit delayed from previous errors
BusyBox tarBusyBox v1.38.0, defconfig✅ rejectserror: tar: can't remove old file .: Is a directory
7-Zip7-Zip (z) 26.05 (x64)⚠️ acceptstree A: _ → d, d/, f (2 B, 092fcfbb)
Python tarfile, filter=data, as in pipCPython 3.15.2✅ rejectserror: OutsideDestinationError: '.' would be extracted to 'DEST', which is outside the destination
Python tarfile, filter=tarCPython 3.15.2✅ rejectserror: OutsideDestinationError: '.' would be extracted to 'DEST', which is outside the destination
Python tarfile, filter=fully_trustedCPython 3.15.2⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
node-tartar 7.5.22⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
node-tar, stricttar 7.5.22⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
tar-fstar-fs 3.1.3, on tar-stream 3.2.2✅ rejectserror: Error: DEST/ is not a valid symlink
Java Commons CompressCommons Compress 1.28.0, Expander, on Java 27.0.1.0.2✅ rejectserror: java.nio.file.FileSystemException: DEST: Is a directory
.NET System.Formats.TarSystem.Formats.Tar of .NET 10.0.14, ExtractToDirectory✅ rejectserror: IOException: Extracting the Tar entry '.' would have resulted in a file outside the specified destination directory: 'DEST/'
PHP PharData, as in ComposerPharData of PHP 8.5.12, as Composer's TarDownloader calls it✅ rejectserror: PharException: Extraction from phar "suite/archives/K06-symlink-named-dot.tar" failed: Cannot extract ".", internal error
Go containerd archive.Applycontainerd v2.4.2, archive.Apply, of go1.27.3⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
Rust tartar 0.4.46, unpack⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
Rust astral-tokio-tarastral-tokio-tar 0.7.1, unpack⚠️ acceptstree B: d/, f (2 B, 092fcfbb)
Rust tar-codec, as in uvtar-codec 0.0.16, with the policies of uv 0.13✅ rejectserror: at byte 512: unsafe member path ".": only a directory may resolve to the extraction root
RubyGemsRubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz✅ rejectserror: Gem::Package::PathError: installing into parent path DEST of DEST is not allowed
R untar, internalutils::untar of R 4.6.2, tar = "internal"✅ rejectserror: object 'from' not found Warning message: In file.symlink(name2, nm) : cannot symlink 'd' to './d', reason 'File exists'
Perl Archive::TarArchive::Tar 3.12 of Perl v5.44.0✅ rejectserror: Could not remove old file 'DEST/.': Is a directory at contrib/matrix/runners/perl/extract.pl line 14. Could not extract '.' at contrib/matrix/runners/perl/extract.pl line 14. Could not extract '.'
Haskell tartar 0.7.2.0, extract, of GHC 9.14✅ rejectserror: createDirectoryLink:createSymbolicLink 'd' to 'DEST/.': already exists (File exists)
Julia Tar.jlTar 1.10.0 of Julia 1.13.3✅ rejectserror: non-directory path ending with '.' component Tar.Header(".", :symlink, 0o644, 0, "d")
live-bootstrap untarmescc-tools-extra a151c245e512, as live-bootstrap pins it✅ rejectserror: Failed to create symlink
live-bootstrap untar, --non-strictmescc-tools-extra a151c245e512, as live-bootstrap pins it⚠️ acceptstree B: d/, f (2 B, 092fcfbb)

Prevalence in release tarballs

The table below shows how many release tarballs have the features of this test case.

ecosystemtarballswith itshare
Spack37,553≤12*≤0.03%*
nixpkgs18,990≤19*≤0.10%*
Guix10,168≤13*≤0.13%*
PyPI10,000≤22*≤0.22%*
crates.io5,0000none
RubyGems5,000≤1*≤0.02%*
live-bootstrap1710none
total (distinct)82,586≤67*≤0.08%*

Note: cells with * are upper bounds. The exact count is likely lower, and awaits a new scan of all tarballs.

See also