Bug 9159 Classpath wizard should not complain when adding missing source folder
Build 20020125 - Define a project A with source folder 'src1'. - Go to the .classpath file and edit it to insert one extra line: <classpathentry kind="src" path="src2"/> below the line referring to first source folder: <classpathentry kind="src" path="src1"/>. - Now, try to add this missing source folder 'src2', it isn't allowed by the wizard, one has to add a basic folder instead. Note: It is not such an uncommon scenario, the classpath modification could simply occur by catching up with a shared classpath having one more source folder on it, and which is locally missing.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
fBuildPathStatus.setWarning(NewWizardMessages.getString("BuildPathsBlock.warning.OutputFolderNotEmpty")); 
						return;
					}
				}
			} catch (CoreException e) {
				JavaPlugin.log(e);
			}
		}
				
		fBuildPathStatus.setOK();
	}
	
	
	
	/**
	 * Creates a runnable that sets the configured build paths.
	 */
	public IRunnableWithProgress getRunnable(final IRemoveOldBinariesQuery reorgQuery) {
		final List classPathEntries= fClassPathList.getElements();
		final IPath path= getOutputLocation();
		
		return new IRunnableWithProgress() {
			public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
				if (monitor == null) {
					monitor= new NullProgressMonitor();
				}				
				monitor.beginTask(NewWizardMessages.getString("BuildPathsBlock.operationdesc"), 10); 
				try {
					createJavaProject(classPathEntries, path, reorgQuery, monitor);
				} catch (CoreException e) {