Fix #5025: Type error when sending a PM without the attachment field

[Deltik]

Motivation and Context

There is a bug where the pm plugin would return fatally error in PHP 8.2 if the user doesn't have permission to add an attachment when sending a private message. This error is due to the fact that the code expects $_FILES['file_userfile'] to be an array, but this array will not be present if the user doesn't have permission to add an attachment.

Fixes #5025

Description

This change adds a check before trying to iterate through $_FILES['file_userfile'], ensuring that it is an array before processing the attachment. If this is not an array, then no actions will be taken on $_FILES['file_userfile'], which avoids the TypeError.

How Has This Been Tested?

The fix was manually tested in a local development environment with PHP 8.2 by sending PMs with and without the attachment permission.

Types of Changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Performance enhancement (non-breaking change which improves efficiency)
• [ ] Code cleanup (non-breaking change which makes code smaller or more readable)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation (a change to man pages or other documentation)

Checklist

• [x] My code adheres to the e107 code style standard.
• [x] I have read the contributing document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests pass.

[codeclimate[bot]]

Code Climate has analyzed commit 5196c4f5 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 0.0% (80% is the threshold).

This pull request will bring the total coverage in the repository to 34.5% (-0.2% change).

View more on Code Climate.

[CaMer0n]

Thank you @Deltik !