Pull Request for joomla/joomla-cms#20280

Summary of Changes

If the open_basedir ini directive contains a path that links to a
symlink, PHP will resolve these paths and then perform the acutal
access check.

Joomla, however, only performed a plain string comparison. As a
result leading to false positives.

Testing Instructions

• Create directory: ~/a/public_html
• Create symlink: ~/b/ pointing to ~/a/
• Configure PHP's openbasedir to contain ~/b/public_html
• Have Joomla create a folder inside ~/a/public_html

Expected result

This should just work with no erorrs whatsoever.

Actual result

An error is presented that the path is not within open_basedir..

Documentation Changes Required

No