MySQL 5.7.5+ support for get_tag_cloud_tags()

Having a Tag Cloud widget on the dashboard when used with MySQL 5.7.5+ (released Sept 2014) results in the following message being displayed:

Syntax Error: SELECT tag,tag_id,COUNT(object_id) AS quantity FROM vtiger_freetags INNER JOIN vtiger_freetagged_objects ON (vtiger_freetags.id = tag_id) WHERE 1=1 AND tagger_id = ? GROUP BY tag ORDER BY quantity DESC LIMIT 0, 100

This is because as of MySQL 5.7.5 ONLY_FULL_GROUP_BY is enabled by default.

Easiest way to solve this seemed to be to add tag_id to the GROUP BY statement thus:

libraries/freetag/freetag.class.php

  function get_tag_cloud_tags($max = 100, $tagger_id = NULL,$module = "",$obj_id = NULL) {
    ...
-   GROUP BY tag
+   GROUP BY tag,tag_id
    ...
  }

It's also worth noting that the freetag library (https://github.com/freetag/freetag) doesn't bother SELECTing tag_id at all, so an alternative solution would be to just remove it, but I didn't look into the code enough to check if this would have any adverse effects or not.

However here is a patch for the original suggestion: vtiger-get_tag_cloud_tags-tag_id.patch