Allow quota write streams with unknown free space

[veryCrunchy]

• Resolves [Bug]: Chunked upload to object-store (S3) primary fails with 413 "Insufficient space" for any user with a finite quota, regardless of free space #61488
• Resolves [Bug]: WebDAV chunked uploads fail with S3 primary storage and per-user quota #61704

Summary

This PR allows quota-wrapped writeStream() calls to proceed when the reported free space is unknown.

With S3 primary object storage and a finite user quota, chunked WebDAV uploads can fail while writing chunks to the DAV upload staging path under uploads/.... For upload staging paths, Quota::free_space() delegates to the wrapped storage. Object-store-backed storage can report free space as unknown, but Quota::writeStream() currently compares the known stream size directly against that value and can raise NotEnoughSpaceException even though the user's destination quota has enough available space.

This changes Quota::writeStream() to treat unknown free space consistently with other quota wrapper write paths such as file_put_contents(), copy(), copyFromStorage(), and moveFromStorage().

A regression test covers writing a known-size stream to an uploads/... path when the wrapped storage reports unknown free space.

AI assistance was used to help inspect logs, reason through the relevant code path, draft the regression test, and organize validation. I prepared this patch after reproducing the issue on an affected Nextcloud instance. After the fix was drafted and tested locally, I found the existing report in #61488 and linked this PR to that issue.

Validation performed:

./autotest.sh sqlite lib/Files/Storage/Wrapper/QuotaTest.php

Result:

OK, but some tests were skipped!
Tests: 115, Assertions: 506, Skipped: 1.

Manual validation was also performed against an affected Nextcloud instance with S3 primary storage and a finite user quota:

• Chunked WebDAV upload failed before this patch with 413 Request Entity Too Large / Insufficient space.
• Applying this one-line change allowed the same chunked WebDAV upload to complete successfully.
• Previously queued rclone VFS cache uploads were able to proceed without new 413 Insufficient space errors after applying the fix.
• Backport requested for stable34. I checked stable33, stable32, stable31, and stable30; those branches do not contain the Quota::writeStream() override with the vulnerable $size < $free comparison.

TODO

• Maintainer review

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes are not required
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[Copilot]

Pull request overview

This PR fixes false NotEnoughSpaceException failures during quota-wrapped writeStream() writes when the underlying storage reports “unknown/unlimited” free space (negative sentinel), which particularly affects chunked WebDAV uploads to uploads/... on S3 primary storage.

Changes:

• Update OC\Files\Storage\Wrapper\Quota::writeStream() to allow known-size writes when free_space() is negative (unknown/unlimited), aligning with other quota wrapper write paths.
• Add a PHPUnit regression test covering a known-size stream write to an uploads/... path when the wrapped storage reports unknown free space.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
lib/private/Files/Storage/Wrapper/Quota.php	Treat negative free_space() as allowed in writeStream() to avoid false “insufficient space” on storages that can’t report free space.
tests/lib/Files/Storage/Wrapper/QuotaTest.php	Adds regression coverage for writing a sized stream to uploads/... when wrapped storage reports unknown free space.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[veryCrunchy]

/backport to stable34

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.