* Add method to Check whether a story can be subdivided in storyTao.

module/story/control.php

@@ -227,7 +227,8 @@ class story extends control
         if($storyID)
         {
             $story = $this->story->getById($storyID);
-            if(($story->status != 'active' or (empty($product->shadow) && $story->stage != 'wait') or (!empty($product->shadow) && $story->stage != 'projected') or $story->parent > 0) and $this->config->vision != 'lite') return print(js::alert($this->lang->story->errorNotSubdivide) . js::locate('back'));
+            $isShadowProduct = !empty($product->shadow);
+            if(!$this->storyTao->checkCanSubdivide($story, $isShadowProduct)) return print(js::alert($this->lang->story->errorNotSubdivide) . js::locate('back'));
         }
 
         if(!empty($_POST))

module/story/tao.php

@@ -881,4 +881,24 @@ class storyTao extends storyModel
         parse_str($extra, $output);
         return $output;
     }
+
+    /**
+     * Check whether a story can be subdivided.
+     *
+     * @param  object    $story
+     * @param  bool      $isShadowProduct
+     * @access protected
+     * @return bool
+     */
+    protected function checkCanSubdivide($story, $isShadowProduct): bool
+    {
+        if($this->config->vision == 'lite') return true;
+
+        if($story->status != 'active')                       return false;
+        if(!$isShadowProduct && $story->stage != 'wait')     return false;
+        if($isShadowProduct && $story->stage != 'projected') return false;
+        if($story->parent > 0)                               return false;
+
+        return true;
+    }
 }