### 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 1.194
diff -u -r1.194 ClasspathTests.java
--- src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	8 Dec 2008 15:49:10 -0000	1.194
+++ src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	11 Dec 2008 14:42:43 -0000
@@ -164,6 +164,40 @@
 	return result;
 }
 
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=171136, ignore class path errors from optional
+// class path entries.
+
+public void test124117() throws CoreException {
+
+	IJavaProject p = null;
+	try {
+
+		p = this.createJavaProject("P0", new String[] {"src0", "src1"}, "bin0");
+		IClasspathAttribute attribute = JavaCore.newClasspathAttribute(IClasspathAttribute.OPTIONAL, "true");
+		JavaCore.setClasspathContainer(
+				new Path("container/default"),
+				new IJavaProject[]{ p },
+				new IClasspathContainer[] {
+					new TestContainer(new Path("container/default"),
+							new IClasspathEntry[]{
+						JavaCore.newLibraryEntry(new Path("/P0/JUNK"), new Path("/P0/SBlah"), new Path("/P0"), null, new IClasspathAttribute[] {attribute}, false)})
+				},
+				null);
+
+		IClasspathEntry newClasspath = JavaCore.newContainerEntry(new Path("container/default"));
+
+		IJavaModelStatus status = JavaConventions.validateClasspathEntry(p, newClasspath, true);
+		
+		assertStatus(
+				"should NOT have complained about missing library as it is optional",
+				"OK",
+				status);
+	
+	} finally {
+		deleteProject ("P0");
+	}
+}
+
 /*  https://bugs.eclipse.org/bugs/show_bug.cgi?id=232816: Misleading problem text for missing jar in user
  *  library. We now mention the container name in this and related diagnostics so the context and connection is clearer.
  *  The bunch of tests with names of the form test232816*() test several paths in the function 
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/ClasspathEntry.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java,v
retrieving revision 1.110
diff -u -r1.110 ClasspathEntry.java
--- model/org/eclipse/jdt/internal/core/ClasspathEntry.java	8 Dec 2008 15:49:12 -0000	1.110
+++ model/org/eclipse/jdt/internal/core/ClasspathEntry.java	11 Dec 2008 14:42:47 -0000
@@ -1745,7 +1745,11 @@
 	 * @return a java model status describing the problem related to this classpath entry if any, a status object with code <code>IStatus.OK</code> if the entry is fine
 	 */
 	public static IJavaModelStatus validateClasspathEntry(IJavaProject project, IClasspathEntry entry, boolean checkSourceAttachment, boolean referredByContainer){
-		return validateClasspathEntry(project, entry, null, checkSourceAttachment, referredByContainer);
+		IJavaModelStatus status = validateClasspathEntry(project, entry, null, checkSourceAttachment, referredByContainer);
+		// https://bugs.eclipse.org/bugs/show_bug.cgi?id=171136, ignore class path errors from optional entries.
+		if (status.getCode() == IJavaModelStatusConstants.INVALID_CLASSPATH && ((ClasspathEntry) entry).isOptional())
+			return JavaModelStatus.VERIFIED_OK;
+		return status;
 	}
 	
 	private static IJavaModelStatus validateClasspathEntry(IJavaProject project, IClasspathEntry entry, IClasspathContainer entryContainer, boolean checkSourceAttachment, boolean referredByContainer){
@@ -1860,6 +1864,9 @@
 					}
 				}
 				IJavaModelStatus status = validateLibraryEntry(path, project, containerInfo, checkSourceAttachment ? entry.getSourceAttachmentPath() : null, entryPathMsg);
+				// https://bugs.eclipse.org/bugs/show_bug.cgi?id=171136, ignore class path errors from optional entries
+				if (status.getCode() == IJavaModelStatusConstants.INVALID_CLASSPATH && ((ClasspathEntry) entry).isOptional())
+					status = JavaModelStatus.VERIFIED_OK;
 				if (!status.isOK())
 					return status;
 				break;
Index: model/org/eclipse/jdt/internal/core/ClasspathValidation.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathValidation.java,v
retrieving revision 1.3
diff -u -r1.3 ClasspathValidation.java
--- model/org/eclipse/jdt/internal/core/ClasspathValidation.java	16 Oct 2008 14:30:30 -0000	1.3
+++ model/org/eclipse/jdt/internal/core/ClasspathValidation.java	11 Dec 2008 14:42:47 -0000
@@ -14,7 +14,6 @@
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaModelStatus;
-import org.eclipse.jdt.core.IJavaModelStatusConstants;
 import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.internal.core.builder.JavaBuilder;
 
@@ -68,8 +67,6 @@
 		 	for (int i = 0; i < rawClasspath.length; i++) {
 				status = ClasspathEntry.validateClasspathEntry(this.project, rawClasspath[i], false/*src attach*/, false /*not referred by a container*/);
 				if (!status.isOK()) {
-					if (status.getCode() == IJavaModelStatusConstants.INVALID_CLASSPATH && ((ClasspathEntry) rawClasspath[i]).isOptional())
-						continue; // ignore this entry
 					this.project.createClasspathProblemMarker(status);
 				}
 			 }
Index: model/org/eclipse/jdt/core/JavaConventions.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/core/JavaConventions.java,v
retrieving revision 1.121
diff -u -r1.121 JavaConventions.java
--- model/org/eclipse/jdt/core/JavaConventions.java	16 Oct 2008 14:30:30 -0000	1.121
+++ model/org/eclipse/jdt/core/JavaConventions.java	11 Dec 2008 14:42:46 -0000
@@ -610,10 +610,7 @@
 	 * @since 2.0
 	 */
 	public static IJavaModelStatus validateClasspathEntry(IJavaProject project, IClasspathEntry entry, boolean checkSourceAttachment){
-		IJavaModelStatus status = ClasspathEntry.validateClasspathEntry(project, entry, checkSourceAttachment, false/*not referred by container*/);
-		if (status.getCode() == IJavaModelStatusConstants.INVALID_CLASSPATH && ((ClasspathEntry) entry).isOptional())
-			return JavaModelStatus.VERIFIED_OK;
-		return status;
+		return ClasspathEntry.validateClasspathEntry(project, entry, checkSourceAttachment, false/*not referred by container*/);
 	}
 
 	/**