Author Topic: ZIP unpack bug  (Read 7352 times)

Suncatcher

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ZIP unpack bug
« on: February 03, 2018, 14:00:47 »
MC cannot properly unpack some ZIP file (example attached). The archive structure is recreated properly, but the contents are lost.
On the screenshot you can see unpacked folder in left panel and original folder contents viewable by click in the right.
I also encounter the error when unpacking via built-in Windows unzipper, and they say Windows doesn't recognize some ZIP algorithms properly. If you use built-in Windows ZIP-engine (which is a bad decision of course), you should at least throw an error to user that archive was not properly extracted, but not silently unpack the empty folder.
7zip unpacks this file properly, so it's better to use its engine.

Mathias (Author)

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Re: ZIP unpack bug
« Reply #1 on: February 03, 2018, 15:20:31 »
No MS engine is not used, it is not available to be used like that. But I guess there are some extended none standard properties used in the zip, that are not fully supported.

Mathias (Author)

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Re: ZIP unpack bug
« Reply #2 on: February 03, 2018, 15:29:37 »
Looks like it is packed with a extended zip algorithm, that not many zip tools support
« Last Edit: February 03, 2018, 15:34:42 by Mathias (Author) »

Suncatcher

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Re: ZIP unpack bug
« Reply #3 on: February 03, 2018, 15:36:26 »
Looks like it is packed with a extended zip algorithm, that not many zip tools support

So maybe it's worth to switch to 7Zip library? It's have LGPL license and can be freely used.

Mathias (Author)

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Re: ZIP unpack bug
« Reply #4 on: February 03, 2018, 15:40:33 »
Looks like it is packed with a extended zip algorithm, that not many zip tools support

So maybe it's worth to switch to 7Zip library? It's have LGPL license and can be freely used.

Don't mix up 7Z lib and there 7Zip app..  there app support more.
MC is using the 7Z lib for 7z file.
But Im not wrapping everything in the 7zip app,  Also the 7Z sdk has a lot of issues and is very limited.
« Last Edit: February 03, 2018, 15:45:18 by Mathias (Author) »