QGIS » QGIS Application

I've spotted a pretty serious bug with joined columns in the attributes table window and symbology classification. Basically, all of the columns following the column which is used to join two tables will be wrongly indexed by not taking into account the removed column which was joined.

Shapefile Table:
id | name | date

To be joined by this XLS Table:
shared_id | extra_a | extra_b | extra_c

When joined, the resulting table would be:
id | name | date | extra_a | extra_b | extra_c

The shared_id column is merged with id, and therefore doesn't show. What seems to happen however is that the QGIS' table column index still takes into account shared_id. So when the user open the attribute table window and try to sort extra_a by clicking on its header, it'll end up sorting extra_b as the extra_a header refers to an index which takes into account shared_id.

Similarly, when doing symbology's graduated / categorized classification by selecting a joined column, the same shift happens.