### Eclipse Workspace Patch 1.0
#P org.eclipse.core.resources
Index: src/org/eclipse/core/internal/resources/LocalMetaArea.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/LocalMetaArea.java,v
retrieving revision 1.42
diff -u -r1.42 LocalMetaArea.java
--- src/org/eclipse/core/internal/resources/LocalMetaArea.java	4 Mar 2010 23:02:51 -0000	1.42
+++ src/org/eclipse/core/internal/resources/LocalMetaArea.java	2 Jun 2010 10:21:02 -0000
@@ -219,6 +219,62 @@
 		return locationFor(target).append(sequenceNumber + F_TREE);
 	}
 
+	void validate() throws CoreException{
+		IPath treeLocation = getTreeLocationFor(getWorkspace().getRoot(), false);
+		IPath tempLocation = getBackupLocationFor(treeLocation);
+		if (!treeLocation.toFile().exists() && !tempLocation.toFile().exists()) {
+			//do not panic yet, it still may be possible to recover, if we can
+			// force the consistency between the version in the .tree name and in master table
+			// TODO: the same kind of checking must be done for .bak files
+			
+			// get the sequence number from the master table
+			String key = getWorkspace().getRoot().getFullPath().append(F_TREE).toString();
+			String masterTableSequenceNumber = getWorkspace().getSaveManager().getMasterTable().getProperty(key);
+			
+			if (masterTableSequenceNumber == null){
+				//nothing in the master table, it looks like first launch
+				//assume success
+				return;
+			}
+			
+			//get the sequence number of the stored .tree file
+			
+			//list all files
+			String[] files = treeLocation.removeLastSegments(1).toFile().list();
+			
+			// find the .tree file. ensure that there is only one
+			// TODO: the case with many  .tree files must be investigated further
+			String matchingTreeFile = null;
+			for (int i = 0; i < files.length; i++) {
+				if (files[i].endsWith(F_TREE) && matchingTreeFile == null) {
+					matchingTreeFile = files[i];
+					continue;
+				}
+				if (files[i].endsWith(F_TREE)) {
+					//panic, more than one .tree file
+					throw new CoreException(new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, "More than one .tree file, you may need to delete .snap")); //$NON-NLS-1$
+				}
+			}
+			
+			// get the sequence number from the .tree file 
+			String fileSequenceNumber = matchingTreeFile.substring(0, matchingTreeFile.indexOf(F_TREE));
+			
+			//fix the master table
+			getWorkspace().getSaveManager().getMasterTable().setProperty(key, fileSequenceNumber);
+			
+			//verify that it was successful operation
+			treeLocation = getTreeLocationFor(getWorkspace().getRoot(), false);
+			tempLocation = getBackupLocationFor(treeLocation);
+			
+			if (!treeLocation.toFile().exists() && !tempLocation.toFile().exists()) {
+				//panic NOW!
+				throw new CoreException(new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, "Corruption, please delete .snap files!")); //$NON-NLS-1$
+			}
+			
+			//SUCCESS
+		}
+	}
+
 	public IPath getWorkingLocation(IResource resource, String id) {
 		return locationFor(resource).append(id);
 	}
Index: src/org/eclipse/core/internal/resources/SaveManager.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/SaveManager.java,v
retrieving revision 1.105
diff -u -r1.105 SaveManager.java
--- src/org/eclipse/core/internal/resources/SaveManager.java	16 Apr 2010 14:26:20 -0000	1.105
+++ src/org/eclipse/core/internal/resources/SaveManager.java	2 Jun 2010 10:21:02 -0000
@@ -966,12 +966,9 @@
 	 */
 	protected void restoreTree(IProgressMonitor monitor) throws CoreException {
 		long start = System.currentTimeMillis();
+		workspace.getMetaArea().validate();
 		IPath treeLocation = workspace.getMetaArea().getTreeLocationFor(workspace.getRoot(), false);
 		IPath tempLocation = workspace.getMetaArea().getBackupLocationFor(treeLocation);
-		if (!treeLocation.toFile().exists() && !tempLocation.toFile().exists()) {
-			savedStates = Collections.synchronizedMap(new HashMap(10));
-			return;
-		}
 		try {
 			DataInputStream input = new DataInputStream(new SafeFileInputStream(treeLocation.toOSString(), tempLocation.toOSString(), TREE_BUFFER_SIZE));
 			try {
@@ -987,6 +984,8 @@
 			System.out.println("Restore Tree for workspace: " + (System.currentTimeMillis() - start) + "ms"); //$NON-NLS-1$ //$NON-NLS-2$
 		}
 	}
+	
+	
 
 	/**
 	 * Restores the trees for the builders of this project from the local disk.