Make sure we only use numbers as length

[nickvergessen]

A try to fix#1707

[mention-bot]

@nickvergessen, thanks for your PR! By analyzing the history of the files in this pull request, we identified @DeepDiver1975, @PVince81 and @owncloud-bot to be potential reviewers.

[derkostka]

@nickvergessen . Sorry, does not help for #1707 .

As soon as the filesize exceeds 32 bit, a 0 byte file is downloaded. Also, if i mount the DAV endpoint in OSX, an error message is thrown instead of downloading the file.

I have tried to understand the Architecture, in order to find things out for myself, but i didn´t get it right now.

[nickvergessen]

Added the unit tests, ready for review since this is fixing a different issue.
cc @LukasReschke@MorrisJobke

[codecov-io]

Current coverage is 57.35% (diff: 100%)

Merging #1740 into master will increase coverage by <.01%

@@ master #1740 diff @@
==========================================
Files 1075 1075 Lines 61314 61315 +1 Methods 6865 6865 Messages 0 0 Branches 0 0 ==========================================
+ Hits 35163 35165 +2 + Misses 26151 26150 -1 
Partials 0 0 

Diff Coverage	File Path
•••••••••• 100%	apps/dav/lib/Connector/Sabre/QuotaPlugin.php

Powered by Codecov. Last update 46406f5...05223a3

[MorrisJobke]

Tested and works 👍

[MorrisJobke]

@karlitschek We should backport this to stable9 and stable10

@nickvergessen Could you open the backport PRs? Thanks

[karlitschek]

please backport 👍