#2416 Cannot rename file in zip from pigz

[Sam Tansy]

It happened to me when I was testing something and wanted to quickly make zip with pigz.. File was named '-' and when I tried to rename it with 7zip it failed.
Here is a script that shows it:

$ echo aaaaaa > a
$ zip zip.zip a
$ 7z rn zip.zip a b
(...)
Updating archive: zip.zip

Items to compress: 0

Files read from disk: 0
Archive size: 158 bytes (1 KiB)
Everything is Ok

$ pigz -K -k a
$ mv a.zip pigz.zip
$ 7z rn pigz.zip a b

Updating archive: pigz.zip

Items to compress: 0

System ERROR:
E_NOTIMPL

As you can see zip file created with zip works, zip file created with pigz doesn't . What is even more surprising, test ($ 7z t pigz.zip) is ok.

It maybe a problem with pigz, maybe with 7zip. I don't know. They follow somewhat strange specs or something, for example zip.zip starts with 50 4B 03 04 │ 14, pigz.zip starts with 50 4B 03 04 │ 2D.

[Igor Pavlov]

That zip archive uses descriptor (stream mode compression).
7-Zip doesn't allow to rename such items by some reasons.
Descptor case has no good specification in zip format.
So diffirent ways to implement it are possible. And if we update such archive, we can broke zip archive, because we don't know what exact way was used to create discriptor records in archive.
So 7-Zip just doesn't allow rename operations for descptor cases.

7z l pigz.zip -slt
Characteristics = UT:M:1 : Descriptor

zip specification:

      4.3.9.3 Although not originally assigned a signature, the value 
      0x08074b50 has commonly been adopted as a signature value 
      for the data descriptor record.  Implementers SHOULD be 
      aware that ZIP files MAY be encountered with or without this 
      signature marking data descriptors and SHOULD account for
      either case when reading ZIP files to ensure compatibility.

The problem in this specification statement: ZIP files MAY be encountered with or without this signature.

So we don't know for 100% what exact size of descriptor record.
We can try to detect size of descriptor record with additional code, but it's not safe for 100% still, and it was not implemented in 7-zip.

[Sam Tansy]

Understood.
Not a bug then.

Can be closed.