Bug 13034 Cannot create a Source Folder in a new Java Project
build 20020404 If you try and create a Source Folder in a Java Project you have just created you get an error preventing you from hitting finish. STEPS 1) Create Java Project Foo 2) Open New->Source Folder 3) Enter Bar as the name - you will get "Cannot nest entry Bar inside entry Foo/Bar" 4) Create a folder Bar. 5) Add it as a source folder in the Properties Dialog for Foo. No problem.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
if (entry.getEntryKind() == IClasspathEntry.CPE_VARIABLE) {
					path= JavaCore.getResolvedVariablePath(path);
				}
				if (path != null) {
					JavaDocLocations.setLibraryJavadocLocation(path, javadocLocation);
				}
			}
		}	
		monitor.worked(1);
				
		fCurrJProject.setRawClasspath(classpath, outputLocation, new SubProgressMonitor(monitor, 7));		
	}
	
	private boolean hasClassfiles(IResource resource) throws CoreException {
		if (resource.isDerived() && "class".equals(resource.getFileExtension())) {
			return true;
		}		
		if (resource instanceof IContainer) {
			IResource[] members= ((IContainer) resource).members();
			for (int i= 0; i < members.length; i++) {
				if (hasClassfiles(members[i])) {
					return true;
				}
			}
		}
		return false;
	}
	
	private void removeOldClassfiles(IResource resource) throws CoreException {
		if (resource.isDerived() && "class".equals(resource.getFileExtension())) {