Bug in repair zip archive



  • I corrupted a zip archive by simply using edit on my windows pc to delete a line of a zip header and then i ried to open it with pa and winzip and it failed. So i used the the pa repair zip archive on it and that said that 6 of the files in the archive were ok, and created a new archive . However the resulting archive opened ok but when i tried to extract or look at the files pa and winzip saied that the files were corrupt but the zip repair tool said they were ok.

    Why is this.

    Thought i’d check out this feature in more detail as i was interested in knowing if it did actually work and it seems it does not.



  • I’m not sure, as I didn’t write the software, but I can guess. The ‘repair zip’ function probably assumes that corruption wil involve changing bytes, not deleting them. Try again, but add a garbage byte for every good one you delete.



  • well what ever i do the program correctly identifies a corrupt zip archive but can not repair it iif you follow my first post about this. The progarm should identify the problem as it does and should not repair it if it can not but in this case it recreates the archive so you can look at it but not extract files from it. It should not say it could create a repair zip if it could not repair it so you can use it.

    when will this be fixed.


  • conexware

    @davidsplash:

    well what ever i do the program correctly identifies a corrupt zip archive but can not repair it iif you follow my first post about this. The progarm should identify the problem as it does and should not repair it if it can not but in this case it recreates the archive so you can look at it but not extract files from it. It should not say it could create a repair zip if it could not repair it so you can use it.

    when will this be fixed.

    Well, there is nothing really wrong here that I can see.

    What happens is that PowerArchiver checks CRC of every file in the archive and recreates and file with files that have correct CRC so those files can be usable.

    What you did is corrupt complete archive by saving it as ASCII while it is actually an binary file. You also deleted lines from the zip file as well .I dont think there is any possibility to save this kind of archive since it is now completly corrupted due to ASCII saving.

    ZIP repair tool is not an magical tool, it will help in cases your zip file got corrupted due to bad media, and let you save rest of the files from the zip file. It certain cases it will not be able to help at all, but is certainly an good tool to have.



  • my point is if it can not help a zip file like the one i made then it should not say it can fix it, if it can’t. Thats the bug i’m reporting.

    False reporting of a fixed zip archive when it is not fixed and can not be.


  • conexware

    When I do exactly what you did, it shows me “corrupted” on single files and “Error fixing archives” error message at the end. Right?



  • yes however it created a reapir achive and in the repair windows beside all the files listed it said ok and created the archive. It should not have created an archive if the resulting archive was corrupt


 

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