Bug 103927 [build path] External jar Dialog cannot set both Javadoc Location and Java Source Attachment in one iteration
Add an external jar to the project. From the context menu of the jar select properties. Select Javadoc location, browse to the desired location. Select Java Source Attachment. Browse to an external file. Press OK. From the context menu of the jar select properties again. Javadoc location is empty. (At this point it can be entered again without problems)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathSupport.java
}
	
	/**
	 * Apply a modified classpath entry to the classpath. The classpath entry can also be from a classpath container.
	 * @param shell If not null and the entry could not be found on the projects classpath, a dialog will ask to put the entry on the classpath
	 * @param newEntry The modified entry. The entry's kind or path must be unchanged.
	 * @param jproject Project where the entry belongs to
	 * @param containerPath The path of the entry's parent container or <code>null</code> if the entry is not in a container
	 * @param monitor The progress monitor to use
	 * @throws CoreException
	 */
	public static void modifyClasspathEntry(Shell shell, IClasspathEntry newEntry, IJavaProject jproject, IPath containerPath, IProgressMonitor monitor) throws CoreException {
		if (containerPath != null) {
			updateContainerClasspath(jproject, containerPath, newEntry, monitor);
		} else {
			updateProjectClasspath(shell, jproject, newEntry, monitor);
		}
	}
	private static void updateContainerClasspath(IJavaProject jproject, IPath containerPath, IClasspathEntry newEntry, IProgressMonitor monitor) throws CoreException {
		IClasspathContainer container= JavaCore.getClasspathContainer(containerPath, jproject);
		if (container == null) {
			throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.ERROR, "Container " + containerPath + " cannot be resolved", null));  
		}
		IClasspathEntry[] entries= container.getClasspathEntries();
		IClasspathEntry[] newEntries= new IClasspathEntry[entries.length];
		for (int i= 0; i < entries.length; i++) {
			IClasspathEntry curr= entries[i];
			if (curr.getEntryKind() == newEntry.getEntryKind() && curr.getPath().equals(newEntry.getPath())) {
				newEntries[i]= newEntry;
			} else {