From 3e84270a99ea13d50cc0a51fe3faf7bbcef7b059 Mon Sep 17 00:00:00 2001
From: anna <Anna.Kozlova@jetbrains.com>
Date: Fri, 8 Oct 2010 19:58:48 +0400
Subject: [PATCH] dnd: do not accept redundant

---
 .../ide/projectView/impl/ProjectViewDropTarget.java    | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/platform/lang-impl/src/com/intellij/ide/projectView/impl/ProjectViewDropTarget.java b/platform/lang-impl/src/com/intellij/ide/projectView/impl/ProjectViewDropTarget.java
index df1878fba764..84bdf9819f8d 100644
--- a/platform/lang-impl/src/com/intellij/ide/projectView/impl/ProjectViewDropTarget.java
+++ b/platform/lang-impl/src/com/intellij/ide/projectView/impl/ProjectViewDropTarget.java
@@ -81,6 +81,16 @@ class ProjectViewDropTarget implements DnDNativeTarget {
     else if (sourceNodes != null && !dropHandler.isValidSource(sourceNodes, targetNode)) {
       return false;
     }
+    if (sourceNodes != null) {
+      boolean redundant = true;
+      for (TreeNode sourceNode : sourceNodes) {
+        if (!dropHandler.isDropRedundant(sourceNode, targetNode)) {
+          redundant = false;
+          break;
+        }
+      }
+      if (redundant) return false;
+    }
     final Rectangle pathBounds = myTree.getPathBounds(myTree.getPathForLocation(point.x, point.y));
     aEvent.setHighlighting(new RelativeRectangle(myTree, pathBounds), DnDEvent.DropTargetHighlightingType.RECTANGLE );
     aEvent.setDropPossible(true, null);