fix +11728 Preview on tree selection reopens randomly

node_modules/ace_tree/lib/ace_tree/mouse/default_handlers.js

@@ -172,7 +172,8 @@ function DefaultHandlers(mouseHandler) {
     };
     
     this.onMouseUp = function(ev) {
-        if (this.isMousePressed) return;
+        if (this.isMousePressed == 2) return; // wait until release capture
+        this.isMousePressed = false;
         var pos = ev.getDocumentPosition();
         var node = this.editor.provider.findItemAtOffset(pos.y);
         if (node && this.$clickNode && this.$clickNode == node) {

node_modules/ace_tree/lib/ace_tree/mouse/mouse_handler.js

@@ -87,7 +87,7 @@ var MouseHandler = function(editor) {
         this.x = ev.x;
         this.y = ev.y;
         
-        this.isMousePressed = true;
+        this.isMousePressed = 2;
 
         // do not move textarea during selection
         var renderer = this.editor.renderer;