Bug 42655 SourceAttachmentBlock does not use dialog font for all widgets [dialogs] [build path]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceAttachmentBlock.java
* project's classpath or updating a container.
	 */
	public IRunnableWithProgress getRunnable(final Shell shell) {
		return new IRunnableWithProgress() {
			public void run(IProgressMonitor monitor) throws InvocationTargetException {				
				try {
					attachSource(shell, monitor);
				} catch (CoreException e) {
					throw new InvocationTargetException(e);
				}
			}
		};
	}	
	
	
	protected void attachSource(final Shell shell, IProgressMonitor monitor) throws CoreException {
		boolean isExported= fEntry.isExported();
		IClasspathEntry newEntry;
		if (fEntry.getEntryKind() == IClasspathEntry.CPE_VARIABLE) {
			newEntry= JavaCore.newVariableEntry(fEntry.getPath(), getSourceAttachmentPath(), getSourceAttachmentRootPath(), isExported);
		} else {
			newEntry= JavaCore.newLibraryEntry(fEntry.getPath(), getSourceAttachmentPath(), getSourceAttachmentRootPath(), isExported);
		}
		if (fContainerPath != null) {
			updateContainerClasspath(fProject, fContainerPath, newEntry, monitor);
		} else {
			updateProjectClasspath(shell, fProject, newEntry, monitor);
		}
	}
	private void updateContainerClasspath(IJavaProject jproject, IPath containerPath, IClasspathEntry newEntry, IProgressMonitor monitor) throws CoreException {