Fix drag-n-drop after folder move/create (#1489648)

program/js/app.js

@@ -5891,6 +5891,9 @@ function rcube_webmail()
     if (!this.gui_objects.subscriptionlist)
       return false;
 
+    // disable drag-n-drop temporarily
+    this.subscription_list.draggable('destroy').droppable('destroy');
+
     var row, n, tmp, tmp_name, rowid, collator, pos, p, parent = '',
       folders = [], list = [], slist = [],
       list_element = $(this.gui_objects.subscriptionlist);

program/js/treelist.js

@@ -482,12 +482,14 @@ function rcube_treelist_widget(node, p)
 
     if (keep_content) {
       if (draggable_opts) {
-        draggable('destroy');
+        if (ui_draggable)
+          draggable('destroy');
         draggable(draggable_opts);
       }
 
       if (droppable_opts) {
-        droppable('destroy');
+        if (ui_droppable)
+          droppable('destroy');
         droppable(droppable_opts);
       }
 
@@ -1061,6 +1063,9 @@ function rcube_treelist_widget(node, p)
     if (!opts) opts = {};
 
     if ($.type(opts) == 'string') {
+      if (opts == 'destroy') {
+        ui_droppable = null;
+      }
       $('li:not(.virtual)', container).droppable(opts);
       return this;
     }
@@ -1109,6 +1114,9 @@ function rcube_treelist_widget(node, p)
     if (!opts) opts = {};
 
     if ($.type(opts) == 'string') {
+      if (opts == 'destroy') {
+        ui_draggable = null;
+      }
       $('li:not(.virtual)', container).draggable(opts);
       return this;
     }
@@ -1121,6 +1129,7 @@ function rcube_treelist_widget(node, p)
         iframeFix: true,
         addClasses: false,
         cursorAt: {left: -20, top: 5},
+        create: function(e, ui) { ui_draggable = ui; },
         helper: function(e) {
           return $('<div>').attr('id', 'rcmdraglayer')
             .text($.trim($(e.target).first().text()));