### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java,v
retrieving revision 1.24
diff -u -r1.24 ExternalFoldersManager.java
--- model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java	27 Apr 2011 15:44:15 -0000	1.24
+++ model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java	3 May 2011 12:25:42 -0000
@@ -91,7 +91,8 @@
 	public static boolean isExternalFolderPath(IPath externalPath) {
 		if (externalPath == null)
 			return false;
-		if (ResourcesPlugin.getWorkspace().getRoot().getProject(externalPath.segment(0)).exists())
+		String firstSegment = externalPath.segment(0);
+		if (firstSegment != null && ResourcesPlugin.getWorkspace().getRoot().getProject(firstSegment).exists())
 			return false;
 		File externalFolder = externalPath.toFile();
 		if (externalFolder.isFile())