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 (fCurrJProject != null) {
			fSourceContainerPage.init(fCurrJProject);
			fLibrariesPage.init(fCurrJProject);
			fProjectsPage.init(fCurrJProject);
		}		
						
		Composite editorcomp= new Composite(composite, SWT.NONE);	
	
		DialogField[] editors= new DialogField[] { fBuildPathDialogField };
		LayoutUtil.doDefaultLayout(editorcomp, editors, true, 0, 0);
		
		int maxFieldWidth= converter.convertWidthInCharsToPixels(40);
		LayoutUtil.setWidthHint(fBuildPathDialogField.getTextControl(null), maxFieldWidth);
		LayoutUtil.setHorizontalGrabbing(fBuildPathDialogField.getTextControl(null));
	
		editorcomp.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		
		if (fShowSourceFolderPage) {
			folder.setSelection(0);
			fCurrPage= fSourceContainerPage;
		} else {
			folder.setSelection(3);
			fCurrPage= ordpage;
			fClassPathList.selectFirstElement();
		}
		WorkbenchHelp.setHelp(composite, IJavaHelpContextIds.BUILD_PATH_BLOCK);				
		return composite;
	}
	
	private Shell getShell() {