Duplicating a cue causes BLT to fail to quit later on

[brunchboy]

Describe the bug
BLT throws an exception during the quitting process that prevents it from quitting if a cue has been duplicated in a show.

To Reproduce
Steps to reproduce the behavior:

1. Start with a show that has at least one track with a cue in it.
2. Duplicate that cue.
3. Try quitting BLT.
4. It will fail, with an exception in the stack trace that looks like (:close show) is returning nil rather than a function to close the show inside beat-link-trigger.show/close-all-shows (currently line 2434).

Exceptions and Stack Traces

2023-Feb-28 10:02:48 ERROR [beat-link-trigger.logs:55] - Uncaught exception on AWT-EventQueue-0
                                                         java.awt.EventDispatchThread.run  EventDispatchThread.java:   90
                                                  java.awt.EventDispatchThread.pumpEvents  EventDispatchThread.java:  101
                                                  java.awt.EventDispatchThread.pumpEvents  EventDispatchThread.java:  109
                                      java.awt.EventDispatchThread.pumpEventsForHierarchy  EventDispatchThread.java:  113
                                         java.awt.EventDispatchThread.pumpEventsForFilter  EventDispatchThread.java:  124
                                      java.awt.EventDispatchThread.pumpOneEventForFilters  EventDispatchThread.java:  203
                                                        java.awt.EventQueue.dispatchEvent           EventQueue.java:  741
            java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege     ProtectionDomain.java:   86
                                              java.security.AccessController.doPrivileged     AccessController.java:  399
                                                                java.awt.EventQueue$4.run           EventQueue.java:  716
                                                                java.awt.EventQueue$4.run           EventQueue.java:  722
                                                    java.awt.EventQueue.dispatchEventImpl           EventQueue.java:  771
                                                  java.awt.event.InvocationEvent.dispatch      InvocationEvent.java:  318
                                com.apple.eawt._AppEventHandler$_AppEventDispatcher$1.run     _AppEventHandler.java:  552
                             com.apple.eawt._AppEventHandler$_QuitDispatcher.performUsing     _AppEventHandler.java:  420
                             com.apple.eawt._AppEventHandler$_QuitDispatcher.performUsing     _AppEventHandler.java:  431
beat_link_trigger.menus.proxy$java.lang.Object$QuitHandler$53b64fb5.handleQuitRequestWith                                
                                                     beat-link-trigger.menus/eval28549/fn                 REPL Input     
                                                                                      ...                                
                                                          beat-link-trigger.triggers/quit              triggers.clj:  114
                                                         java.awt.Component.dispatchEvent            Component.java: 4833
                                                        java.awt.Window.dispatchEventImpl               Window.java: 2780
                                                     java.awt.Container.dispatchEventImpl            Container.java: 2324
                                                     java.awt.Component.dispatchEventImpl            Component.java: 5001
                           seesaw.core.proxy$javax.swing.JFrame$Tag$fd407141.processEvent                                
                                                             java.awt.Window.processEvent               Window.java: 2044
                     seesaw.core.proxy$javax.swing.JFrame$Tag$fd407141.processWindowEvent                                
                                                    javax.swing.JFrame.processWindowEvent               JFrame.java:  298
                                                       java.awt.Window.processWindowEvent               Window.java: 2085
                                               java.awt.AWTEventMulticaster.windowClosing  AWTEventMulticaster.java:  357
                                               java.awt.AWTEventMulticaster.windowClosing  AWTEventMulticaster.java:  358
                                                      seesaw.event/fn/reify/windowClosing                 event.clj:  290
                                                                        seesaw.event/fire                 event.clj:  263
                                      beat-link-trigger.triggers/create-trigger-window/fn              triggers.clj: 1567
                                                   beat-link-trigger.show/close-all-shows                  show.clj: 2434
                                                                      clojure.core/every?                  core.clj: 2698
                                                beat-link-trigger.show/close-all-shows/fn                  show.clj: 2434
java.lang.NullPointerException: Cannot invoke "clojure.lang.IFn.invoke(Object, Object)"

[brunchboy]

The problem is being set up because somewhere in the act of duplicating the cue, open-shows is being corrupted, and an entry with a file key of nil is being added, with only partial content:

{ :contents { :phrases { nil { :cues { :hue 62.5 } } } }, :last { :playing-phrases { 1 nil, 2 nil }, :phrases {} }, :phrases {}, :playing-phrases { 1 nil, 2 nil } }

[brunchboy]

Ah ha! The problem was that assign-cue-hue was being called with something that was not a track/phrase context (because of a simple typo, passing content rather than context), and it needs one in order to be able to update the show to record the most recent color assignment; this was causing corruption of the show structure. I have fixed this, as well as adding validation to all the show-updating functions so they will throw an exception making it easy to find such mistakes, rather than corrupting the structure in the future.