Notice: Only variables should be passed by reference

[olafgrabienski]

After hovering on a (partially working) Beautytips Node link and/or after clicking somewhere else to close the tooltip again, I get the following notice in DBlog:

Only variables should be passed by reference in beautytips_node_beautytips_node_output() (line 75 of /PATH-TO/modules/beautytips_node/beautytips_node.module).

Interestingly, I see the same error on a Drupal test page using Beautytips Node via simplytest.me, PHP versions are in both cases 7.0.2x.

[olafgrabienski]

I was able to reproduce the issue on a fresh Backdrop site using the official Beautytips API release and the current code of Beautytips Node. My PHP version is 7.1.12.

This is the line in question:

print backdrop_render(node_view($node, 'beautytips_node'));

Hopefully helpful pages:

• https://drupal.stackexchange.com/questions/6322/strict-warning-only-variables-should-be-passed-by-reference
• http://php.net/manual/en/language.references.pass.php