Cart editing

If we make a new superTrack and move an existing track into it, then we have a problem with old sessions, ones that predate this change:

If you load an old saved session, the was saved before the superTrack-move and the session has this track on, then the track disappears if you load the session after the superTrack-move, and there is no error at all.

This is because the superTracks is not set to "show" in the old cart.

Cart editing solves this. Cart editing consists of two parts:

• a version number for trackDb, always written into all saved carts, so we can distinguish old from new carts.
• a piece of C code (in cartEdit.c called from cart.c) that adds a new cart variable, always when a cart that is loaded, anytime or anywhere from any CGI and that cart is is older than the current trackDb.

So, before you move a track into a new superTrack you must do one thing:

  ask an engineer to add code to cartEdit.c

Then wait until the code goes out the normal way to the RR. After the release, any time, you can do these two things:

1) increase the version number in the top-level trackDb.ra file, at the top 2) add the superTrack and move the old track into it