Windows: Additional write permissions check

[Alkl58]

The Problem: The isWritable() function checks only(?) for write permissions for the user, owner, group or anyone(?).

Its technically correct - when opening the folder permissions of an SMB share in Explorer, it shows that the user doesn't have those permissions. The actual permission for being able to read/write/delete is not covered by the "base" permissions of Explorer, it's covered by the "special permissions".

It looks similar to this (just imageine it being an SMB share):

For more info check my comment: #3910 (comment)

This PR adds an additional actual write test for Windows hosts.

This PR fixes #3910

First time using C++, comments/improvements welcome!

[Alkl58]

Also closes/fixes: #3201

[Alkl58]

Test on SMB share:

Test on normal folder:

Test on protected system folder:

Test on write protected folder:

[codecov]

Codecov Report

Merging #5510 (d72c932) into master (406bad8) will decrease coverage by 1.63%.
Report is 10 commits behind head on master.
The diff coverage is n/a.

❗ Current head d72c932 differs from pull request most recent head 67205a2. Consider uploading reports for the commit 67205a2 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5510      +/-   ##
==========================================
- Coverage   60.56%   58.94%   -1.63%     
==========================================
  Files         145      143       -2     
  Lines       18846    18313     -533     
==========================================
- Hits        11414    10794     -620     
- Misses       7432     7519      +87     

see 78 files with indirect coverage changes

[Alkl58]

Will this be merged at some point? Or should I close it?

[claucambra]

It looks good at first glance, but need to find time to test

[claucambra]

A couple of small comments

[claucambra]

Hi @Alkl58 are you able to make the requested changes? If not we are happy to take over the PR and include your changes with our own fixes :)

[Alkl58]

Hi @Alkl58 are you able to make the requested changes? If not we are happy to take over the PR and include your changes with our own fixes :)

Sorry for the delay. Should be all good now :)

[nextcloud-desktop-bot]

AppImage file: nextcloud-PR-5510-67205a2cec923c441ec1e962388e287219073afa-x86_64.AppImage

To test this change/fix you can simply download above AppImage file and test it.

Please make sure to quit your existing Nextcloud app and backup your data.

[Alkl58]

Just a FYI: Apparently I completely broke my local dev environment after trying to install all qt dependencies. I'll reinstall my system / use a VM, will take some time so I can properly debug / fix things.

[allexzander]

Just a FYI: Apparently I completely broke my local dev environment after trying to install all qt dependencies. I'll reinstall my system / use a VM, will take some time so I can properly debug / fix things.

sure, no worries, I've noticed you're using fopen function from C, that only takes const char* as filename. We need to use QFile instead. If you are ok, I can take over the PR and incorporate changes.

[Alkl58]

@allexzander sure, thats probably faster, sorry for the hassle

[allexzander]

Moved to #6209