the method ScanCentralHeader of Type TZipFileList can be changed to the following code (or similar), in order to make extraction of CRX (Chrome Extension Files) possible via zipengine.
Rem
bbdoc: Scans the central header for files. Returns true if successful.
End Rem
Method ScanCentralHeader:Int()
SeekStream(zipFile, 0)
Local magic_number:Int = ReadInt(zipFile);
Local zip_start_pos:Int = 0;
' CRX FILE (Google Chrome Extension File), see: http://developer.chrome.com/extensions/crx.html
If magic_number = $34327243 Then
zip_start_pos:+4;
ReadInt(zipFile); ' CRX Version
zip_start_pos:+4;
zip_start_pos:+ReadInt(zipFile); ' length of crx public key
zip_start_pos:+4;
zip_start_pos:+ReadInt(zipFile); ' length of crx signature
zip_start_pos:+4;
SeekStream(zipFile, zip_start_pos);
magic_number:Int = ReadInt(zipFile);
EndIf
' first check to see if its even a valid ZIP file
If magic_number <> $04034b50 Then
DebugLog("Invalid ZIP file!")
Return False
EndIf
Local header_start:Int = 0
' jump to the end
SeekStream(zipFile, StreamSize(zipFile) - 4)
' seek the end central directory structure
While Not StreamPos(zipFile) = 0
Local sig:Int = ReadInt(zipFile)
If sig = $06054b50 Then
' jump to start of central dir location
SeekStream(zipFile, StreamPos(zipFile) + 12)
header_start = ReadInt(zipFile)
Exit
Else
' rewind 3 bytes and try again
SeekStream(zipFile, StreamPos(zipFile) - 5)
EndIf
EndWhile
' if we found the header, then process
If Not header_start Then
DebugLog("unable to locate central directory!")
Return False
EndIf
header_start:+zip_start_pos;
' seek to the start of the central directory
SeekStream(zipFile, header_start)
While True And Not Eof(zipFile)
Local entry:SZipFileEntry = SZipFileEntry.Create()
If entry.header.fill(zipFile) Then
FileList.AddLast(entry)
' read filename
entry.zipFileName = entry.header.FileName
extractFilename(entry)
Else
Exit
EndIf
EndWhile
Return True
EndMethod