Bug 54737 Libraries dialog doesn't remember status of items in library tree
Preferences > Java > Build Path > User Libraries: The dialog does not seem to correctly remember the status of the items in the "Defined user libraries" tree. When I leave the dialog I close (un-cascade) all items. When I open the dialog again, most of the items are open (cascaded) again. This is disturbing because I cannot overview the items. It's like opening the Windows explorer with not only the drives shown but all folders being open.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/dialogfields/TreeListDialogField.java
up();
		} else if (index == fDownButtonIndex) {
			down();
		} else {
			return false;
		}
		return true;
	}
	
	/*
	* @see DialogField#doFillIntoGrid
	*/
	public Control[] doFillIntoGrid(Composite parent, int nColumns) {
		PixelConverter converter= new PixelConverter(parent);
		assertEnoughColumns(nColumns);
		Label label= getLabelControl(parent);
		GridData gd= gridDataForLabel(1);
		gd.verticalAlignment= GridData.BEGINNING;
		label.setLayoutData(gd);
		Control list= getTreeControl(parent);
		gd= new GridData();
		gd.horizontalAlignment= GridData.FILL;
		gd.grabExcessHorizontalSpace= false;
		gd.verticalAlignment= GridData.FILL;
		gd.grabExcessVerticalSpace= true;
		gd.horizontalSpan= nColumns - 2;
		gd.widthHint= converter.convertWidthInCharsToPixels(50);
		gd.heightHint= converter.convertHeightInCharsToPixels(6);
		list.setLayoutData(gd);
		Composite buttons= getButtonBox(parent);