Merge remote-tracking branch 'upstream/master'

# Conflicts:
#	README.md

plugin/notes/speaker-view.html

@@ -414,14 +414,24 @@
 					}
 					// Messages sent by the reveal.js inside of the current slide preview
 					else if( data && data.namespace === 'reveal' ) {
+						const supportedEvents = [
+							'slidechanged',
+							'fragmentshown',
+							'fragmenthidden',
+							'paused',
+							'resumed',
+							'previewiframe',
+							'previewimage',
+							'previewvideo',
+							'closeoverlay'
+						];
+
 						if( /ready/.test( data.eventName ) ) {
 							// Send a message back to notify that the handshake is complete
 							window.opener.postMessage( JSON.stringify({ namespace: 'reveal-notes', type: 'connected'} ), '*' );
 						}
-						else if( /slidechanged|fragmentshown|fragmenthidden|paused|resumed/.test( data.eventName ) && currentState !== JSON.stringify( data.state ) ) {
-
+						else if( supportedEvents.includes( data.eventName ) && currentState !== JSON.stringify( data.state ) ) {
 							dispatchStateToMainWindow( data.state );
-
 						}
 					}
 
@@ -494,9 +504,12 @@
 						notes.classList.add( 'hidden' );
 					}
 
+					// Don't show lightboxes in the upcoming slide
+					const { previewVideo, previewImage, previewIframe, ...upcomingState } = data.state;
+
 					// Update the note slides
 					currentSlide.contentWindow.postMessage( JSON.stringify({ method: 'setState', args: [ data.state ] }), '*' );
-					upcomingSlide.contentWindow.postMessage( JSON.stringify({ method: 'setState', args: [ data.state ] }), '*' );
+					upcomingSlide.contentWindow.postMessage( JSON.stringify({ method: 'setState', args: [ upcomingState ] }), '*' );
 					upcomingSlide.contentWindow.postMessage( JSON.stringify({ method: 'next' }), '*' );
 
 				}