Bug 64298 JAR files already in build path still shown when adding JARs.
When adding JARs to the Java build path in 3.0M9, the JAR's that are already added do not get filtered out anymore like with all previous builds (M8 and lower). Instead, the complete list of all available JARs is shown.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/LibrariesWorkbookPage.java
public Control getControl(Composite parent) {
		PixelConverter converter= new PixelConverter(parent);
		
		Composite composite= new Composite(parent, SWT.NONE);
			
		LayoutUtil.doDefaultLayout(composite, new DialogField[] { fLibrariesList }, true, SWT.DEFAULT, SWT.DEFAULT);
		LayoutUtil.setHorizontalGrabbing(fLibrariesList.getTreeControl(null));
		
		int buttonBarWidth= converter.convertWidthInCharsToPixels(24);
		fLibrariesList.setButtonsMinWidth(buttonBarWidth);
		
		fLibrariesList.getTreeViewer().setSorter(new CPListElementSorter());
		
		fSWTControl= composite;
				
		return composite;
	}
	
	private Shell getShell() {
		if (fSWTControl != null) {
			return fSWTControl.getShell();
		}
		return JavaPlugin.getActiveWorkbenchShell();
	}
	
	
	private class LibrariesAdapter implements IDialogFieldListener, ITreeListAdapter {