Fixed User Mentions sometimes generate errors

[Xon]

If a post has a valid user mention, and then a user mention which is too long, the tagging dies.

This is because of the length test in XenForo_Model_UserTagging::_getTagMatchUsers:

		foreach ($matches AS $key => $match)
		{
			if (utf8_strlen($match[1][0]) > 50)
			{
				// longer than max username length
				continue;
			}
...
		}
...
			foreach ($matchKeys AS $key)
			{
				if ($user["match_$key"])
				{
					$usersByMatch[$key][$user['user_id']] = $userInfo;
				}
			}

The line "if ($user["match_$key"])" is at fault, as that key will never exist because it's generator was skipped.

This needs to be wrapped in an !empty() or isset() && $value guard.

 

[Mike]

We had this reported once before, but didn't have the reproduce case so didn't manage to trigger it. But no problem reproducing it here with the explanation. Fixed now, thanks.