std.zip.Iterator.Entry.extract fails for some zip files

[kartikynwa]

Zig Version

0.14.0-dev.2370+5c6b25d9b

Steps to Reproduce and Observed Behavior

1. Prepare the zip files

mkdir ziptest && cd ziptest
head --bytes=100 /dev/urandom > file.txt

# xbps-query -p pkgver zip
# zip-3.0_6
zip compressed_1.zip file.txt
#  adding: file.txt (stored 0%)
zip -fz compressed_2.zip file.txt
#  adding: file.txt (stored 0%)
rm file.txt

2. Prepare the zig code to extract said files

cat <<EOF > extract.zig
const std = @import("std");
const zip = std.zip;

pub fn main() !void {
    var args = std.process.args();
    _ = args.next();
    const zip_path: []const u8 = args.next().?;

    const zip_file = try std.fs.cwd().openFile(zip_path, .{});
    defer zip_file.close();
    const zip_stream = zip_file.seekableStream();

    try std.zip.extract(std.fs.cwd(), zip_stream, .{});

    std.debug.print("Extracted successfully: {s}\n", .{zip_path});
}
EOF

3. Extract the zip files

zig run extract.zig -- compressed_1.zip && rm file.txt
# Extracted successfully: compressed_1.zip
# removed 'file.txt'
zig run extract.zig -- compressed_1.zip && rm file.txt
# error: ZipMismatchCompLen
# /home/ks/stuff/zig/zig-linux-x86_64-0.14.0-dev/lib/std/zip.zig:471:25: 0x1058d46 in extract (extract)
#                         return error.ZipMismatchCompLen;
#                         ^
# /home/ks/stuff/zig/zig-linux-x86_64-0.14.0-dev/lib/std/zip.zig:588:23: 0x105a47a in extract__anon_1914 (extract)
#         const crc32 = try entry.extract(seekable_stream, options, &filename_buf, dest);
#                       ^
# /home/ks/stuff/zig/ziptest/extract.zig:13:5: 0x105aa06 in main (extract)
#     try std.zip.extract(std.fs.cwd(), zip_stream, .{});
#     ^

Expected Behavior

The file compressed_2.zip should be extracted successfully. compressed_2.zip is a perfectly valid zip file that passes integrity checks like:

unzip -t compressed_2.zip
# Archive:  compressed_2.zip
#     testing: file.txt                 OK
# No errors detected in compressed data of compressed_2.zip.

This is happening because the file is created using the -fz flag. I am unsure of zip lore but it causes issue with this part of the zip library's code:

zig/lib/std/zip.zig

Lines 469 to 474 in 30169d1

	if (local_header.compressed_size != 0 and
	local_header.compressed_size != self.compressed_size)
	return error.ZipMismatchCompLen;
	if (local_header.uncompressed_size != 0 and
	local_header.uncompressed_size != self.uncompressed_size)
	return error.ZipMismatchUncompLen;

For this particular zip file both local_header.compressed_size and local_header.uncompressed_size are 0xffffffff. The zip spec says something about when these fields are to be 0xffffffff but it goes over my head. Sorry about that.