closedir() should be called conditionally

[GaryJ]

BuddyPress 14.3.4 has a PHP 8 compatibility bug where closedir() is called outside the conditional block that checks if opendir() succeeded. This causes fatal errors on platforms that intentionally return empty strings for avatar directories (e.g. WPVIP's file service).

In two places in BuddyPress, closedir() is called unconditionally:

• Line 571 in bp_core_fetch_avatar()
• Line 865 in bp_core_delete_existing_avatar()

This generates a noisy set of PHP warnings that can't be worked around with filters, and only a patch being applied to BuddyPress works. If the closedir() called was inside the conditional that uses opendir(), then the same intended behaviour would still work, but without the warning from PHP 8.

[GaryJ]

See ​this change for BuddyBoss which tackles the same issue.

[espellcaste]

I can handle this. Thanks for the bug report and the prior art.

[johnjamesjacoby]

In 14140:

Core: improve PHP8 compatibility by only calling closedir() on proper opendir() resources.

The intent of this change is to avoid closedir() producing warnings & errors when opendir() had previously returned false.

It also adds a missing closedir() call to the bp_attachments_cover_image_generate_file() function.

Props GaryJ.

Fixes #9307.