### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core.tests.model
Index: src/org/eclipse/jdt/core/tests/model/ClasspathTests.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ClasspathTests.java,v
retrieving revision 1.196
diff -u -r1.196 ClasspathTests.java
--- src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	15 Jan 2009 14:21:07 -0000	1.196
+++ src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	10 Feb 2009 08:24:07 -0000
@@ -526,6 +526,26 @@
 }
 
 /*
+ * Ensures that creating an external library folder referenced by a library entry and refreshing the workspace doesn't log a NPE
+ * (regression test for https://bugs.eclipse.org/bugs/show_bug.cgi?id=262363 )
+ */
+public void testAddExternalLibFolder7() throws CoreException {
+	try {
+		createJavaProject("P", new String[0], new String[] {getExternalResourcePath("externalLib")}, "");
+		waitForAutoBuild();
+		createExternalFolder("externalLib");
+		startLogListening(null/*listen to Platform's log*/);
+		getWorkspaceRoot().refreshLocal(IResource.DEPTH_INFINITE, null);
+		waitForManualRefresh();
+		assertLogEquals("");
+	} finally {
+		stopLogListening();
+		deleteExternalResource("externalLib");
+		deleteProject("P");
+	}
+}
+
+/*
  * Ensures that adding a library entry for an existing external ZIP archive doesn't generate a marker
  */
 public void testAddZIPArchive1() throws CoreException {
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/DeltaProcessor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java,v
retrieving revision 1.331
diff -u -r1.331 DeltaProcessor.java
--- model/org/eclipse/jdt/internal/core/DeltaProcessor.java	7 Jan 2009 16:29:42 -0000	1.331
+++ model/org/eclipse/jdt/internal/core/DeltaProcessor.java	10 Feb 2009 08:24:15 -0000
@@ -21,6 +21,7 @@
 import org.eclipse.core.resources.IResourceChangeEvent;
 import org.eclipse.core.resources.IResourceDelta;
 import org.eclipse.core.resources.IResourceDeltaVisitor;
+import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.resources.ResourcesPlugin;
@@ -1897,7 +1898,18 @@
 				return;
 
 			case IResourceChangeEvent.PRE_REFRESH:
-				JavaModelManager.getExternalManager().refreshReferences((IProject) resource, null);
+				IProject [] projects = null;
+				Object o = event.getSource();
+				if (o instanceof IProject) {
+					projects = new IProject[] { (IProject) o };
+				} else if (o instanceof IWorkspace) {
+					// https://bugs.eclipse.org/bugs/show_bug.cgi?id=261594. The single workspace refresh
+					// notification we see, implies that all projects are about to be refreshed.
+					 projects = ((IWorkspace) o).getRoot().getProjects(IContainer.INCLUDE_HIDDEN);
+				}
+				for (int i = 0; projects != null && i < projects.length; i++) {
+					JavaModelManager.getExternalManager().refreshReferences(projects[i], null);
+				}
 				return;
 
 			case IResourceChangeEvent.POST_CHANGE :