Bug 30727 exclusion filters: cannot remove [build path]
20030129 create a jproject and a src folder in it add 2 packages to it a.b and c.d exclude c/d/ from the classpath open the java build path dialog, select the source folders expand the tree node select 'Exclusion filter: /c/d/' press 'Remove' seems to be removed, right? wrong. open the dialog again - the filter for /c/d is still there
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceContainerWorkbookPage.java
dialog.addFilter(filter);
		dialog.setInput(fCurrJProject.getProject().getParent());
		dialog.setSorter(new ResourceSorter(ResourceSorter.NAME));
		if (existing == null) {
			dialog.setInitialSelection(fCurrJProject.getProject());
		} else {
			dialog.setInitialSelection(existing.getResource());
		}		
		if (dialog.open() == FolderSelectionDialog.OK) {
			Object[] elements= dialog.getResult();	
			CPListElement[] res= new CPListElement[elements.length];
			for (int i= 0; i < res.length; i++) {
				IResource elem= (IResource)elements[i];
				res[i]= newCPSourceElement(elem);
			}
			return res;
		}
		return null;
	}
	
	private List getExistingContainers(CPListElement existing) {
		List res= new ArrayList();
		List cplist= fFoldersList.getElements();
		for (int i= 0; i < cplist.size(); i++) {
			CPListElement elem= (CPListElement)cplist.get(i);
			if (elem != existing) {
				IResource resource= elem.getResource();
				if (resource instanceof IContainer) { 
					res.add(resource);	
				}