My problem is that when user upload avatar, ImageMagick creates small and medium variants which are CHMOD 600. This means they are not displayed in posts. What should I do to force IM to CHMOD files correct (644)?
Large avatar has proper permissions after upload, medium and small not, so I think large one is untouched but medium and small are chmoded improperly after conversion? ImageMagick is set as image processor in AdminCP.
I've tried with $config['chmodWritableValue'] = 0644; in config.php (find it suggested somewhere) but it makes no any changes.
I've seen things like this before when servers have disabled the chmod function. You can check admin.php?tools/phpinfo and look at the disable_functions line to see if it's disabled there.
If so, unfortunately there isn't anything you can directly do about it. You need to contact your host and have them re-enable the chmod function or they need to fix the umask on the user PHP is running as to not create files as 0600.