0042032: [19Q4] [Restaurants] Sharing a table between two users usually breaks the system

Description

The module does not seem prepared to manage concurrency. While trying to create and pay different tickets for the same table using more than one user, the system usually ends up broken.

Steps To Reproduce

Note: There are several possible scenarios. Here I'll describe one of them.

1. Having an empty table, enter with userA and create a ticket for that table.
2. Add an item to that table.
3. In a separate terminal, enter as userB and create an unassigned ticket.
4. Add an item to that ticket.
5. With userB, assign the ticket to the table selected in step 1. Upon selection, the table should show also the ticket created by userA.
6. As userB, select the ticket created in step 3 and assign it to a Customer.
7. Pay the ticket. The window keeps behind the ticket from userA but a blank window is shown so no action other than refresh is possible. See attached screenshot.

Proposed Solution

We cannot allow to assign unassigned tickets from Terminal B to a table opened in Terminal A.
If we try to set to a ticket a table opened in another terminal, we should show a popup with the error.

Issue History
Date Modified	Username	Field	Change
2019-10-15 16:56	plujan	New Issue
2019-10-15 16:56	plujan	Assigned To	=> Retail
2019-10-15 16:56	plujan	File Added: BlockedTicket.png
2019-10-15 16:56	plujan	Triggers an Emergency Pack	=> No
2019-11-11 16:02	migueldejuana	Proposed Solution updated

Relationships [ Relation Graph ] [ Dependency Graph ]