Bug 73984 Editing user library jar path after path change does not work [build path]
1) Create a directory containing jar file 2) Add this jar file to a new user library 3) Rename directory from 1) 4) Update the path to jar file in user libraries (select old jar reference, select new location in browser, open -> path is not updated, but old path is still used
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/UserLibraryPreferencePage.java
public LoadSaveDialog(Shell shell, boolean isSave, List existingLibraries, IDialogSettings dialogSettings) {
			super(shell);
			setShellStyle(getShellStyle() | SWT.MAX | SWT.RESIZE);
			
			PixelConverter converter= new PixelConverter(shell);
			
			fExistingLibraries= existingLibraries;
			fSettings= dialogSettings;
			fLastFile= null;
			fIsSave= isSave;
			
			int defaultWidth= converter.convertWidthInCharsToPixels(80);
			int defaultHeigth= converter.convertHeightInCharsToPixels(34);
			String lastSize= fSettings.get(PREF_USER_LIBRARY_LOADSAVE_SIZE);
			if (lastSize != null) {
				fInitialSize= StringConverter.asPoint(lastSize, new Point(defaultWidth, defaultHeigth));
			} else {
				fInitialSize= new Point(defaultWidth, defaultHeigth);
			}
		
			if (isSave()) {
				setTitle(PreferencesMessages.getString("UserLibraryPreferencePage.LoadSaveDialog.save.title")); 
			} else {
				setTitle(PreferencesMessages.getString("UserLibraryPreferencePage.LoadSaveDialog.load.title"));				 
			}
			
			fLocationField= new StringButtonDialogField(this);
			fLocationField.setLabelText(PreferencesMessages.getString("UserLibraryPreferencePage.LoadSaveDialog.location.label")); 
			fLocationField.setButtonLabel(PreferencesMessages.getString("UserLibraryPreferencePage.LoadSaveDialog.location.button")); 
			fLocationField.setDialogFieldListener(this);