TYPO3 Core

Ok, here are my debugging results.

In our case $this->tt_contentConfig['cols']) was containing an empty string which resulted in an 1 item containing array $cList = array(0 => '') after being exploded. $this->tt_contentConfig['cols']) was empty because of a TSconfig snippet mod.SHARED.colPos_list = 99, which removed all the tt_content column in page module. (Background: other tables have been added to page view, so we wouldn't need any tt_content columns!)

Up until 4.5.35 this work just fine. In order to get this working again I suggest to use t3lib_div::trimExplode() instead of explode(). See attached patch file for 4.5.x.

Is that still an issue with current 6.2 and 7.6 installations?

By reading the code the change from explode to trimExplode seems valid. explode(',', '') results in array(0 => '') (an array with the string that should be exploded)
This is not what the rest of the code expects. An empty array is a better value as it will prevent foreach loops from doing anything.

Patch set 1 for branch TYPO3_6-2 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/49000

Applied in changeset 44949dff5e24e7e292bbe820a41b2e29b930936d.