automatic join for belongsTo association with cross databases not work

[ericj]

In cakephp 2.2.x, we can have automatic join work for cross databases with a simple patch:

"lib/Model/Datasource/DboSource.php function read()
if ($model->useDbConfig === $linkModel->useDbConfig) {
...

to
if ($model->useDbConfig === $linkModel->useDbConfig || $type=='belongsTo') {
...

But in recent 2.5.x, the read function seems have some changes,
I was wondering how to make the cross database auto join for belongsTo ?

[markstory]

We can't always do cross db joins as the dbs could be on different servers or database server types.

[lorenzo]

The misunderstanding was solved in IRC by talking to @ericj. Cake will not inspect into datasource configurations for resolving possible joins. You need to either use the same datasource or set the table name correctly to include the database name