Converted aggregate graph cannot be edited

A converted aggregate graph cannot be edited via the web UI. As soon as the edit form is submitted, the graph breaks.

Steps to reproduce the behavior:

1. Convert existing aggregate graph to normal graph
2. Visit edit view of converted graph
3. Hit the save button
4. Graph preview and edit view is different

Part of edit view and graph before:

Edit view and graph after hitting save:

This issue occurs on v1.2.8 (also observed in 1.2.7, can't say for previous versions)

[TheWitness]

Can you update to 1.2.9 and see if you can repeat this?

[TheWitness]

Oh, I just reproduced.

[TheWitness]

This should be fixed now. Just update graphs.php from the 1.2.x branch.

Can confirm it's working fine now. Very nice, thanks!