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
private IClasspathEntry[] getRawClasspath() {
		IClasspathEntry[] currEntries= new IClasspathEntry[fClassPathList.getSize()];
		for (int i= 0; i < currEntries.length; i++) {
			CPListElement curr= (CPListElement) fClassPathList.getElement(i);
			currEntries[i]= curr.getClasspathEntry();
		}
		return currEntries;
	}
		
	/* (non-Javadoc)
	 * @see org.eclipse.jdt.internal.ui.wizards.buildpaths.BuildPathBasePage#isEntryKind(int)
	 */
	public boolean isEntryKind(int kind) {
		return kind == IClasspathEntry.CPE_LIBRARY || kind == IClasspathEntry.CPE_VARIABLE || kind == IClasspathEntry.CPE_CONTAINER;
	}
	
	/*
	 * @see BuildPathBasePage#getSelection
	 */
	public List getSelection() {
		return fLibrariesList.getSelectedElements();
	}
	/*
	 * @see BuildPathBasePage#setSelection
	 */	
	public void setSelection(List selElements) {
		fLibrariesList.selectElements(new StructuredSelection(selElements));
	}	
}