fix(dav): handle HTML in CalDAV invitations

[ChristophWurst]

• Resolves: #

Summary

This avoids rendering issues with certain characters.

TODO

• ...

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
• 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)

[ChristophWurst]

/backport to stable32

[ChristophWurst]

/backport to stable31

[ChristophWurst]

/backport to stable30

[ChristophWurst]

/backport to stable29

[ChristophWurst]

/backport to stable28

[tcitworld]

No problem with that, but shouldn't it be handled directly by addBodyListItem instead?

[ChristophWurst]

No problem with that, but shouldn't it be handled directly by addBodyListItem instead?

No because sometimes we want the HTML to render, e.g. for the strike-through formatting of event updates.

[kesselb]

Error: apps/dav/lib/CalDAV/Schedule/IMipService.php:79:109: LessSpecificReturnType: The inferred return type 'string' for OCA\DAV\CalDAV\Schedule\IMipService::generateDiffString is more specific than the declared return type 'null|string' (see https://psalm.dev/088)

[kesselb]

Error: apps/dav/lib/CalDAV/Schedule/IMipService.php:79:109: LessSpecificReturnType: The inferred return type 'string' for OCA\DAV\CalDAV\Schedule\IMipService::generateDiffString is more specific than the declared return type 'null|string' (see https://psalm.dev/088)

I assume Psalm was unable to detect the return type for Sabre\VObject\Property::getValue. Now with the value being wrapped in htmlspecialchars it's always a string. Yet I'm not sure if we can trust sabre's return type annotations 🙈