data loss after editing geojson

[jfirebaugh]

1. Open http://geojson.io/#id=gist:anonymous/08b09c066e72a801616c
2. Edit the coordinates of the polygon in the "JSON" tab
3. Cmd+S

Result: It reverted to the original data, your edits are gone.

[jfirebaugh]

Finally figured out that this was because of a validation error (first coord != last). To avoid data loss, save should be disabled in this case, or it should save even though there's a validation error.