PHP mbstring extension requirement check fails on upgrade

[raamdev]

This was originally reported on WordPress.org.

The report indicates that updating to a version of Comet Cache that requires the mbstring extension (>= v160416, I believe) from a version that does not (<= v160227), when the server does not have the PHP mbstring extension installed, results in a fatal error.

The bug that is likely causing this issue was fixed in WP-PHP-RV v160712, so the next release of Comet Cache should include this newer version of the requirements handler.

[raamdev]

Next Release Changelog:

• Bug Fix: Fixed a bug where the Comet Cache PHP requirements check would fail and produce a fatal error when upgrading from a version of Comet Cache that did not require an extension that is now required by newer releases. This would occur when, for example, the required PHP mbstring extension was missing. Props @jaswsinc for finding the bug. See Issue #817.

[raamdev]

Comet Cache v160917 has been released and includes changes from this GitHub Issue. See the v160917 announcement for further details.

---

This issue will now be locked to further updates. If you have something to add related to this GitHub Issue, please open a new GitHub Issue and reference this one (#817).