### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/JavaProject.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/JavaProject.java,v
retrieving revision 1.441
diff -u -r1.441 JavaProject.java
--- model/org/eclipse/jdt/internal/core/JavaProject.java	22 Dec 2010 05:56:55 -0000	1.441
+++ model/org/eclipse/jdt/internal/core/JavaProject.java	2 Feb 2011 14:17:49 -0000
@@ -2744,6 +2744,10 @@
 		if (resolvedEntry.getEntryKind() == IClasspathEntry.CPE_LIBRARY && ExternalFoldersManager.isExternalFolderPath(resolvedPath)) {
 			externalFoldersManager.addFolder(resolvedPath, true/*scheduleForCreation*/); // no-op if not an external folder or if already registered
 		}
+		IPath sourcePath = resolvedEntry.getSourceAttachmentPath();
+		if (sourcePath != null && ExternalFoldersManager.isExternalFolderPath(sourcePath) ) {
+			externalFoldersManager.addFolder(sourcePath, true);
+		}
 	}
 
 	private void copyFromOldChainedEntry(ClasspathEntry resolvedEntry, ClasspathEntry chainedEntry) {