[mythtv] Bug: MythTV 0.20 DVB networkid 0 becomes NULL in database

[Kenneth Falck]

Hi, I thought I'd report this:

When I scan for DVB-C channels on a virgin MythTV 0.20 (Ubuntu 6.10) 
system, MythTV inserts NULL instead of 0 for networkid in the 
dtv_multiplex table.

This causes all scanned channels to fail with "Found channel, but it 
doesn't match existing tsid" and results in no channels found. I was 
able to fix this by manually running:
UPDATE dtv_multiplex SET networkid=0 WHERE networkid IS NULL;
And then running a re-scan of existing transports.

Unfortunately, the re-scan of all existing transports found only a part 
of the channels. I had to to additional scans of single transports to 
find all that I wanted. Also a number of extra non-tv channels (software 
downloads, radio channels) were detected that I had to delete manually. 
They caused some weird tuning problems, because their logical channel 
numbers overlapped with some TV channels.

Overall, it seems MythTV may have some confusion with the standard DVB 
service identifier scheme <originalnetworkid>.<transportid>.<serviceid>. 
Every DVB service should be identified with, and only with, this 
complete combination.