Allow upload of empty folders via drag & drop in WebUI

[AlexAndBear]

Description

Enhancement: Allow empty folder uploads via webUI

Before this PR, drag and drop an empty folder did not work, there was no
response in the webUI anyways.
While uploading a folder with a text file and an empty folder,
the folder with the text file was created but the empty folder wasn't.

With this PR the upper scenarios work now.

Related Issue

• Fixes Drag and drop empty folder not working #32235
• Fixes https://github.com/owncloud/enterprise/issues/3117

Motivation and Context

• I have my music collection on my computer with dirs from interprets a-z
• I want to upload my music collection to ownCloud
• Some folders have not been uploaded as they are empty
• Bad :(

How Has This Been Tested?

Tested on browsers

• IE 11 -> Dropping folders does not work, even with content or not -> this issue was prexisting Does not work
• Chrome/Chromium -> Works
• Edge -> Works
• Firefox -> Works
• Safari -> Works

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Database schema changes (next release will require increase of minor version instead of patch)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:
• Changelog item, see TEMPLATE

[AlexAndBear]

Note, we are touching apps/files/js/jquery.fileupload.js here.

Which has been already done by our devs, e.g bf04daf#diff-ae6d415538c7caff6e1d808b2d442226a680c6ca54576ba4e9f08317bdeee387

[phil-davis]

Just a few suggestions for words in text. If you are sorting out test coverage, you can consider these also. IMO we should not say "This PR" in changelogs, because readers of the changelog may not know what "PR" is.

[phil-davis]

Works for me - I manually tested drag-and-drop of an empty folder, folder with a file, and flder with a mix of files and folders. I dropped them into the root, or on top of (=into) an existing folder of a user. All combinations worked.

Tested on Ubuntu 20.04 with these browsers:
Chrome Version 94.0.4606.54 (Official Build) (64-bit)
Firefox 92.0
Opera Version:79.0.4143.50

[jvillafanez]

I might be mistaking with a similar issue, but I think there were problems because the behavior is browser-dependent.
Please, include a list of browsers where you've tested the feature.

[AlexAndBear]

@jvillafanez Please reference the GitHub or Portal issue here

I suspect IE and Opera won't work here, because of the limited API https://developer.mozilla.org/en-US/docs/Web/API/DataTransferItem/webkitGetAsEntry

[phil-davis]

I suspect IE and Opera won't work here

I tested Opera on Ubuntu 20.04 and it works.

[AlexAndBear]

@micbar can we merge as approved, adding js tests for this case would be much overhead

[jvillafanez]

assuming tests pass

[phil-davis]

LGTM. I manually tested with 3 different browsers. See comment #39285 (comment)

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

12.5% Coverage
0.0% Duplication