Heartbeat:

- Pass the actual error to the jQuery event 'heartbeat-connection-lost'.
- When in error state, keep trying to connect even when no response is expected until the error is cleared.
See #23216.

git-svn-id: https://develop.svn.wordpress.org/trunk@24577 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/heartbeat.js

@@ -107,7 +107,7 @@ window.wp = window.wp || {};
 
 				if ( trigger && ! self.connectionLost ) {
 					self.connectionLost = true;
-					$(document).trigger( 'heartbeat-connection-lost' );
+					$(document).trigger( 'heartbeat-connection-lost', [error] );
 				}
 			} else if ( self.connectionLost ) {
 				errorcount = 0;
@@ -136,7 +136,7 @@ window.wp = window.wp || {};
 
 			// If nothing to send (nothing is expecting a response),
 			// schedule the next tick and bail
-			if ( empty ) {
+			if ( empty && ! self.connectionLost ) {
 				connecting = false;
 				next();
 				return;