Blitz Zip Userlib (Create an manipulate zip files)

Ow .. that's stupid, the example was wrong .. I understand the error checking now. It seems my experiment returned a ZIPAPI_BUF_ERROR.
However, I don't understand why. When I poke random data in a bank, size 5000, the compressed version of the bank can be uncompressed. However, when I leave the original bank empty, or fill it with predicable numbers, it can't. Is that right ?

	; Include required libraries
	Include "../Blitz_Basic_Bank.bb"
	Include "../Blitz_File_FileName.bb"
	Include "../Blitz_File_ZipApi.bb"		

	;create bank	
	bank = CreateBank(5000)

;	;without these lines, it returns a data error
;   ;but with them, the bank can be extracted 
;
;	For i = 0 To BankSize(bank) / 2
;		PokeByte bank, i, Rand(255)
;	Next
	
	;compress
	bank1 = ZipApi_Compress(bank)
	bank2 = ZipApi_UnCompress(bank1)
	Print "org:" + BankSize(bank)
	Print "cmp:" + BankSize(bank1)
	
	;cmp. ratio
	Print "scale = " + BankSize(bank) / Float(BankSize(bank1))

	Print "error? " + bank2
	
	If bank2 > 0 Then
	
		;test uncompressed bank
		Print "unc:" + BankSize(bank2)
	
	End If
	
	FreeBank bank
	FreeBank bank1
	FreeBank bank2

	WaitKey()
	End	

I think the structure you chose is a good solution. I don't think is it necessary to be able to compress banks with a length of zero. If any error occurs, it might be better to abort, it will make debugging much easier I think.