Please describe the problem:
When QIF securities are imported, new GnuCash commodities may need to be created. However, commodity creation is skipped for those QIF securities that have ever been imported in the past - even if they were originally imported into a different GnuCash data file.

Steps to reproduce:
1. Make a backup your qif-accounts-map file, then remove the original.
2. Start GnuCash with --nofile.
3. Import a QIF file containing a transaction that involves a QIF security, such as the example attached.
4. Notice that a new GnuCash commodity was created during by the importer.
5. Restart GnuCash, again with --nofile.
6. Import the same QIF file.
7. Notice that no GnuCash commodity gets created by the importer.


Actual results:
The QIF importer does not create a commodity.

Expected results:
The QIF importer should create a commodity, and that commodity should be used for the GnuCash account that holds the shares.

Does this happen every time?
Yes.

Other information:
The problem occurs because the QIF importer assumes that any QIF security that has been imported in the past will already exist as a commodity in the GnuCash data file. This is not a valid assumption for users that switch between multiple GnuCash data files.