[mythtv] Scheduler bug

[Bruce Markey]

Friday night, I had "Late Show With David Letterman"
scheduled as the only thing in it's time slot with three
tuners available. It got assigned to two tuners on two
different machines. The hint that something was wrong
was DB errors for duplicates in recordedmarkup. The
recorded table has one hostname so the other recording
file was orphaned.

I assumed this was an anomaly due to too many experiments
with scheduling. However, the same thing happened again
today during college basketball when I'd done nothing
unusual. There should have been three games recorded but
one game went to two tuners so another game got bumped.
I had no debugging info to see what might be happening.

Tonight, with some output, I saw this on a one tuner
standalone system (local frontend and backend).


Started recording 1 = College Basketball
Changing from None to RecordingOnly         // State change
audio volume set to '32768'                 // for BB gane
Changing from RecordingOnly to None
adding: nordtv as a player 1
Started recording 1 = Nashville Star
Changing from None to RecordingOnly         // State change
Changing from RecordingOnly to None
Started recording 1 = Saturday Night Live
Changing from None to RecordingOnly         // SNL starts
Started recording 1 = Saturday Night Live   // Already recording,
adding: nordtv as a player 1                // shouldn't happen
adding: nordtv as a player 0
adding: nordtv as a player 0                // (using frontend)
Started recording 1 = Saturday Night Live   // Still thinks it
adding: nordtv as a player 1                // needs recording
Changing from RecordingOnly to None         // SNL ends

During SNL, it appeared in red on the Watch Recordings
page and also in white in the Fix Conflicts page.

When a recording is assigned to a busy tuner, it silently
fails and the current recording continues. Therefore, this
may happen often on a single tuner system and go unnoticed.

I assume that either "RemoveRecording(nextRecording)" fails
to remove the item from "recordingList" or something else
re-adds it after it had been removed.

I've added more debug statements and scheduled a bunch of stuff
for both the three tuner and one tuner systems but this seems
to be random so I don't know when I'll see it again.

--  bjm