Multiple edits lose work item data

[Diogo Matsubara]

Steps to reproduce:
1. Open https://blueprints.launchpad.dev/kubuntu/+spec/krunch-desktop-plan in two different tabs
2. In the first tab, add some work items:
 foo bar: TODO
 foo bar2: POSTPONED
 foo bar3: DONE
3. In the second tab, add more items
 foo bar4: TODO
 foo bar 5: POSTPONED

Since the second tab was loaded before the work items field had any data on it, when the form is submitted, the previous data added in the first tab is deleted. Perhaps, Launchpad could detect that another edit was done while the page was stale and warn the user.

[Guilherme Salgado (salgado)]

This probably happens with any inline text fields. I think it should be combined with bug 577462. Fixing this would require a significant amount of infrastructure work

[Guilherme Salgado (salgado)]

Apparently launchpadlib can detect this and prevent the data loss but support for this hasn't been added to Y.EditableText yet. I've just confirmed that the same data loss occurs if you perform the steps described here on the whiteboard.

[Francis J. Lacoste (flacoste)]

Th lp.client JS library would need to support sending an If-Match header containing the Etag of the object you are editing. And then add support for handling the 412 Precondition error that would result when an editing conflict happens.