if (!isset($GLOBALS['vbulletin']->db))

[Captain Tycoon]

Can anyone tell me what that means?
if (!isset($GLOBALS['vbulletin']->db))

[kh99]

Do you want the full explanation or the bottom line? Basically it's saying "if the vbulletin database connection hasn't been initialized". Seems most likely that's it just a "safety" check rather than something that's expected to happen.

[Captain Tycoon]

Thank you,

I asked because it does happen which stumped me and I wasn't sure what it meant. Although what I don't understand is the database connection is fine on all other pages except the includes/paymentapi/class_2checkout.php and the other class files in the same folder - this only recently started happening so I'm not really sure what's causing it (visiting the link directly).

[kh99]

Oh, yeah, that script is not meant to be visited directly. It's only meant to be included by other scripts, which would have the database object created already. But to be honest I don't really understand the reasoning behind doing that check since the only thing in the file is a class definition.

ETA: I notice that it's at the top of many files, so I guess it's a standard thing that they decided to put at the top of each file that's meant to only be included, to head off any unforseen issues if someone accesses it directly.

[Paul M]

Its actually checking if the database class exists, not if you have a connection, but yes, its just a sanity check.