### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/ChangeClasspathOperation.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ChangeClasspathOperation.java,v
retrieving revision 1.2
diff -u -r1.2 ChangeClasspathOperation.java
--- model/org/eclipse/jdt/internal/core/ChangeClasspathOperation.java	10 Jul 2006 20:50:44 -0000	1.2
+++ model/org/eclipse/jdt/internal/core/ChangeClasspathOperation.java	15 May 2007 08:54:21 -0000
@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.jdt.internal.core;
 
+import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.JavaModelException;
@@ -43,6 +44,11 @@
 		DeltaProcessor deltaProcessor = state.getDeltaProcessor();
 		ClasspathChange change = (ClasspathChange) deltaProcessor.classpathChanges.get(project.getProject());
 		if (this.canChangeResources) {
+			// workaround for https://bugs.eclipse.org/bugs/show_bug.cgi?id=177922
+			if (isTopLevelOperation() && !ResourcesPlugin.getWorkspace().isTreeLocked()) {
+				new ClasspathValidation(project).validate();
+			}
+				
 			// delta, indexing and classpath markers are going to be created by the delta processor 
 			// while handling the .classpath file change
 
#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 1.162
diff -u -r1.162 ClasspathTests.java
--- src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	9 May 2007 11:31:58 -0000	1.162
+++ src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	15 May 2007 08:54:23 -0000
@@ -3715,6 +3715,37 @@
 }
 
 /*
+ * Ensures that renaming a .jar file and updating the classpath in a PRE_BUILD event doesn't leave markers
+ * (regression test for bug 177922 FlexibleProjectContainer refresh logic sporadically leaves project with "missing library" error on rename/delete)
+ */
+public void testRenameJar() throws CoreException {
+	try {
+		final IJavaProject p = createJavaProject("P", new String[0], new String[] {"/P/lib/test1.jar"}, "");
+		createFolder("/P/lib");
+		createFile("/P/lib/test1.jar", "");
+		// at this point no markers exist
+		
+		// register a listener that updates the classpath in a PRE_BUILD event
+		IResourceChangeListener listener = new IResourceChangeListener(){
+			public void resourceChanged(IResourceChangeEvent event) {
+				try {
+					p.setRawClasspath(new IClasspathEntry[] {JavaCore.newLibraryEntry(new Path("/P/lib/test2.jar"), null, null)}, null);
+				} catch (JavaModelException e) {
+					e.printStackTrace();
+				}
+			}
+		};
+		getWorkspace().addResourceChangeListener(listener, IResourceChangeEvent.PRE_BUILD);
+		
+		// rename .jar
+		getFile("/P/lib/test1.jar").move(new Path("/P/lib/test2.jar"), false, null);
+		assertMarkers("Unexpected markers", "", p);
+	} finally {
+		deleteProject("P");
+	}
+}
+
+/*
  * Ensures that unknown classpath attributes in a .classpath file are not lost when read and rewritten.
  * (regression test for bug 101425 Classpath persistence should be resilient with unknown attributes)
  */