### Eclipse Workspace Patch 1.0
#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 1.326
diff -u -r1.326 DeltaProcessor.java
--- model/org/eclipse/jdt/internal/core/DeltaProcessor.java	27 Aug 2008 08:59:19 -0000	1.326
+++ model/org/eclipse/jdt/internal/core/DeltaProcessor.java	4 Sep 2008 17:04:07 -0000
@@ -1013,8 +1013,10 @@
 		if (elementType == IJavaElement.JAVA_PROJECT) {
 			// project add is handled by JavaProject.configure() because
 			// when a project is created, it does not yet have a java nature
-			if (delta != null && JavaProject.hasJavaNature((IProject)delta.getResource())) {
+			IProject project;
+			if (delta != null && JavaProject.hasJavaNature(project = (IProject)delta.getResource())) {
 				addToParentInfo(element);
+				this.manager.getPerProjectInfo(project, false /* don't create info */).rememberExternalLibTimestamps();
 				if ((delta.getFlags() & IResourceDelta.MOVED_FROM) != 0) {
 					Openable movedFromElement = (Openable)element.getJavaModel().getJavaProject(delta.getMovedFromPath().lastSegment());
 					currentDelta().movedTo(element, movedFromElement);
Index: model/org/eclipse/jdt/internal/core/ClasspathChange.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathChange.java,v
retrieving revision 1.18
diff -u -r1.18 ClasspathChange.java
--- model/org/eclipse/jdt/internal/core/ClasspathChange.java	27 Jun 2008 16:03:51 -0000	1.18
+++ model/org/eclipse/jdt/internal/core/ClasspathChange.java	4 Sep 2008 17:04:07 -0000
@@ -333,26 +333,6 @@
 					}
 				}
 				addClasspathDeltas(delta, pkgFragmentRoots, IJavaElementDelta.F_REMOVED_FROM_CLASSPATH);
-
-				// remember timestamp of jars that were removed (in case they are added as external jar in the same operation)
-				for (int j = 0, length = pkgFragmentRoots.length; j < length; j++) {
-					PackageFragmentRoot root = pkgFragmentRoots[j];
-					if (root.isArchive() && !root.isExternal()) {
-						URI location = root.resource().getLocationURI();
-						File file = null;
-						try {
-							IFileStore fileStore = EFS.getStore(location);
-							file = fileStore.toLocalFile(EFS.NONE, null);
-						} catch (CoreException e) {
-							// continue
-						}
-						if (file == null)
-							continue;
-						long timeStamp = DeltaProcessor.getTimeStamp(file);
-						IPath externalPath = new org.eclipse.core.runtime.Path(file.getAbsolutePath());
-						state.getExternalLibTimeStamps().put(externalPath, new Long(timeStamp));
-					}
-				}
 			} else {
 				// remote project changes
 				if (this.oldResolvedClasspath[i].getEntryKind() == IClasspathEntry.CPE_PROJECT) {
Index: model/org/eclipse/jdt/internal/core/DeltaProcessingState.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessingState.java,v
retrieving revision 1.50
diff -u -r1.50 DeltaProcessingState.java
--- model/org/eclipse/jdt/internal/core/DeltaProcessingState.java	27 Jun 2008 16:03:51 -0000	1.50
+++ model/org/eclipse/jdt/internal/core/DeltaProcessingState.java	4 Sep 2008 17:04:07 -0000
@@ -507,18 +507,33 @@
 
 	public void saveExternalLibTimeStamps() throws CoreException {
 		if (this.externalTimeStamps == null) return;
+		
+		// cleanup to avoid any leak ( https://bugs.eclipse.org/bugs/show_bug.cgi?id=244849 )
+		HashSet toRemove = new HashSet();
+		if (this.roots != null) {
+			Enumeration keys = this.externalTimeStamps.keys();
+			while (keys.hasMoreElements()) {
+				Object key = keys.nextElement();
+				if (this.roots.get(key) == null) {
+					toRemove.add(key);
+				}
+			}
+		}
+		
 		File timestamps = getTimeStampsFile();
 		DataOutputStream out = null;
 		try {
 			out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(timestamps)));
-			out.writeInt(this.externalTimeStamps.size());
+			out.writeInt(this.externalTimeStamps.size() - toRemove.size());
 			Iterator entries = this.externalTimeStamps.entrySet().iterator();
 			while (entries.hasNext()) {
 				Map.Entry entry = (Map.Entry) entries.next();
 				IPath key = (IPath) entry.getKey();
-				out.writeUTF(key.toPortableString());
-				Long timestamp = (Long) entry.getValue();
-				out.writeLong(timestamp.longValue());
+				if (!toRemove.contains(key)) {
+					out.writeUTF(key.toPortableString());
+					Long timestamp = (Long) entry.getValue();
+					out.writeLong(timestamp.longValue());
+				}
 			}
 		} catch (IOException e) {
 			IStatus status = new Status(IStatus.ERROR, JavaCore.PLUGIN_ID, IStatus.ERROR, "Problems while saving timestamps", e); //$NON-NLS-1$