MDL-39351 collapsed editor had grey bars above and below.

lib/editor/tinymce/yui/build/moodle-editor_tinymce-collapse/moodle-editor_tinymce-collapse-debug.js

@@ -94,6 +94,12 @@ Y.extend(COLLAPSE, Y.Base, {
         } else {
             this.toggle_collapse(thisToggleNode, editortable, 1);
         }
+
+        // When TinyMCE initialises itself, it adds a height to the table.
+        // Unfortuately, the height it sets is too big for when the editor is collpsed.
+        // Fortunately, the hight is not necessary, so we can just remove it.
+        // (If you re-size the editor then it will remove this style attribute itself.)
+        editortable.setStyle('height', '');
     },
 
     /**
@@ -105,8 +111,7 @@ Y.extend(COLLAPSE, Y.Base, {
       */
     toggle_collapse : function(button, editortable, newstate) {
         var toolbar = editortable.one('td.mceToolbar').ancestor('tr'),
-            statusbar = editortable.one('.mceStatusbar').ancestor('tr'),
-            editor, iframe, size;
+            statusbar = editortable.one('.mceStatusbar').ancestor('tr');
 
         // Check whether we have a state already.
         if (typeof newstate === 'undefined') {

lib/editor/tinymce/yui/build/moodle-editor_tinymce-collapse/moodle-editor_tinymce-collapse.js

@@ -94,6 +94,12 @@ Y.extend(COLLAPSE, Y.Base, {
         } else {
             this.toggle_collapse(thisToggleNode, editortable, 1);
         }
+
+        // When TinyMCE initialises itself, it adds a height to the table.
+        // Unfortuately, the height it sets is too big for when the editor is collpsed.
+        // Fortunately, the hight is not necessary, so we can just remove it.
+        // (If you re-size the editor then it will remove this style attribute itself.)
+        editortable.setStyle('height', '');
     },
 
     /**
@@ -105,8 +111,7 @@ Y.extend(COLLAPSE, Y.Base, {
       */
     toggle_collapse : function(button, editortable, newstate) {
         var toolbar = editortable.one('td.mceToolbar').ancestor('tr'),
-            statusbar = editortable.one('.mceStatusbar').ancestor('tr'),
-            editor, iframe, size;
+            statusbar = editortable.one('.mceStatusbar').ancestor('tr');
 
         // Check whether we have a state already.
         if (typeof newstate === 'undefined') {

lib/editor/tinymce/yui/src/collapse/js/collapse.js

@@ -92,6 +92,12 @@ Y.extend(COLLAPSE, Y.Base, {
         } else {
             this.toggle_collapse(thisToggleNode, editortable, 1);
         }
+
+        // When TinyMCE initialises itself, it adds a height to the table.
+        // Unfortuately, the height it sets is too big for when the editor is collpsed.
+        // Fortunately, the hight is not necessary, so we can just remove it.
+        // (If you re-size the editor then it will remove this style attribute itself.)
+        editortable.setStyle('height', '');
     },
 
     /**
@@ -103,8 +109,7 @@ Y.extend(COLLAPSE, Y.Base, {
       */
     toggle_collapse : function(button, editortable, newstate) {
         var toolbar = editortable.one('td.mceToolbar').ancestor('tr'),
-            statusbar = editortable.one('.mceStatusbar').ancestor('tr'),
-            editor, iframe, size;
+            statusbar = editortable.one('.mceStatusbar').ancestor('tr');
 
         // Check whether we have a state already.
         if (typeof newstate === 'undefined') {