fix 12077 Carousel update not possible

We have to make sure the TinyMCE updates the underlying
textarea before we grab the text from it

docs/changelog/7.x.x.txt

@@ -10,6 +10,7 @@
  - added: lineage increment_step and increment_offset for multi-master DB clusters
  - Change Group INSERT to REPLACE to prevent merge problems in multi-master DB clusters
  - added #12078: Add alt tag to default Image template
+ - fixed #12077: Carousel update not possible
 
 7.10.11
  - fixed #12057: WebGUI::Search, assetIds search clause

www/extras/wobject/Carousel/carousel.js

@@ -95,6 +95,9 @@ WebGUI.Carousel.Editor.prototype.handleSubmit
         item.itemId = id.value;
 
         var text    = elem.getElementsByTagName( 'textarea' )[0];
+        // Force the TinyMCE to update the textarea
+        tinyMCE.getInstanceById( text.id ).save();
+
         item.text   = text.value;
 
         item.sequenceNumber = i;