TC creates invalid ZIPs

[MarcinW]

Under some circumstances, TC creates an invalid ZIP archive (but with no data loss). Steps to reproduce:

1) Create file "C:\test\file.txt" on your local disk, file may be empty.
2) Select folder "test" and pack it into "test.zip". We get an archive with the following structure: "test.zip\test\file.txt".
3) Go into the archive and press F4 on the "file.txt" - after confirming it will be unpacked to the TEMP folder and opened with the Notepad.
4) Switch from the Notepad to the TC and - in the "test.zip" - delete file "file.txt" and folder "test".
Please note: folder "test" has been removed from the internal ZIP directory (at the end of a ZIP file - see ZIP file format).
5) Now switch to the Notepad, edit file and close Notepad with saving changes.
6) TC informs that file has been changed - repack it into the ZIP file.
7) TC creates again file "test\file.txt" inside "test.zip", but it doesn't recreate folder "test" (which was removed in step 4).
In other words, internal ZIP directory (at the end of our ZIP file) contains now "test\file.txt" record (for file), but doesn't contain "test" record (for folder).

In such way we created an invalid ZIP file, without folder "test", but with a file inside this folder. Now go into "test.zip\test\file.txt" and delete "file.txt" - file seems not to be deleted(!) and refreshing shows, that folder "test" also disappeared (because, in fact, it wasn't existing).

To be fixed: when repacking a file into an archive, make sure that the full folder tree is existing. If not - recreate.

Regards

[MVV]

AFAIK empty directories are not necessary in ZIPs, structure is built using relative file paths inside of archive. As I see, TC removes file correctly but it doesn't update panel so it is still shows folder with removed file after removing.

[MarcinW]

So - because empty directories are not necessary in ZIP files (and other archives?) - there is also a second fix to be done: after deleting last file from the "nonexistent" folder, panel contents should be properly refreshed, i.e. we should be moved one level up in the folder hierarchy.

[MVV]

i.e. we should be moved one level up in the folder hierarchy

That's what 7-Zip does with such archive.

[ghisler(Author)]

Indeed empty folders are not a requirement in ZIP archives. TC adds them when packing normally so you can remove all files from the folder and still keep the folder itself. But it's not required by the ZIP standard.

[MarcinW]

Ok, ok. However for consistency and for user convenience, TC could recreate folder structure when repacking a file. And panel should be properly refreshed when deleting last file from the "nonexistent" folder.

[MarcinW]

For the sake of completeness: there is also much more trivial way of creating ZIP file without directory structure:
- search for some files with Alt+F7,
- feed results to listbox,
- pack result files to ZIP (with paths).

[MarcinW]

There is also another problem with ZIPs without directory structure: searching for directory names (with Alt+F7) doesn't work as it can be expected.

Below is a test ZIP archive. The structure is:

test.zip\dir1
test.zip\dir1\file1.txt
test.zip\dir2\file2.txt

Now if we go into test.zip and search for "dir" with Alt+F7, we will find "dir1", but we will not find "dir2".



So, as a summary of this thread - three things can be improved:

1) directory structure could be created, when packing with paths to a ZIP archive (after editing a packed file or when adding to the ZIP archive from the panel, after feeding search results to that panel),

2) panel contents could be properly refreshed, after deleting last file from the "nonexistent" directory (for ZIPs created by previous versions of TCMD or by other tools),

3) search algorithm could be improved, to include also "nonexistent" directories (for ZIPs created by previous versions of TCMD or by other tools).

Regards



test.b64:

Code: Select all

MIME-Version: 1.0
Content-Type: application/octet-stream; name="test.zip"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.zip"

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AAAAAA4AAABkaXIxL2ZpbGUxLnR4dAMAUEsDBBQAAgAIAC8NyUIAAAAAAgAAAAAAAAAOAAAAZGly
Mi9maWxlMi50eHQDAFBLAQIUABQAAgAAACcNyUIAAAAAAAAAAAAAAAAFAAAAAAAAAAAAEAAAAAAA
AABkaXIxL1BLAQIUABQAAgAIACsNyUIAAAAAAgAAAAAAAAAOAAAAAAAAAAAAIAAAACMAAABkaXIx
L2ZpbGUxLnR4dFBLAQIUABQAAgAIAC8NyUIAAAAAAgAAAAAAAAAOAAAAAAAAAAAAIAAAAFEAAABk
aXIyL2ZpbGUyLnR4dFBLBQYAAAAAAwADAKsAAAB/AAAAAAA=