Bug 120544 [build path] Editing external source folder does not persist
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
if (fCurrPage != null) {
				List selection= fCurrPage.getSelection();
				if (!selection.isEmpty()) {
					newPage.setSelection(selection, false);
				}
			}
			fCurrPage= newPage;
			fPageIndex= tabItem.getParent().getSelectionIndex();
		}
	}
	
	private int getPageIndex(int entryKind) {
		switch (entryKind) {
			case IClasspathEntry.CPE_CONTAINER:
			case IClasspathEntry.CPE_LIBRARY:
			case IClasspathEntry.CPE_VARIABLE:
				return 2;
			case IClasspathEntry.CPE_PROJECT:
				return 1;
			case IClasspathEntry.CPE_SOURCE:
				return 0;
		}
		return 0;
	}
	
	private CPListElement findElement(IClasspathEntry entry) {
		for (int i= 0, len= fClassPathList.getSize(); i < len; i++) {
			CPListElement curr= (CPListElement) fClassPathList.getElement(i);
			if (curr.getEntryKind() == entry.getEntryKind() && curr.getPath().equals(entry.getPath())) {
				return curr;