Bug 82231 [build path] Hard to find type restriction compiler problem preferences
I20050104-1600 There compiler preference page contains a Warning/Error node with many sub-entries . I tried to find where I could change the 'warning' for the access of internal types to 'error'. No luck until I realized that the Build node also contains Warning/Error settings.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/OptionsConfigurationBlock.java
public boolean performApply() {
		return processChanges(null); 
	}
	
	protected boolean processChanges(IWorkbenchPreferenceContainer container) {
		IScopeContext currContext= fLookupOrder[0];
	
		List  changedOptions= new ArrayList();
		boolean needsBuild= getChanges(currContext, changedOptions);
		if (changedOptions.isEmpty()) {
			return true;
		}
		
		boolean doBuild= false;
		if (needsBuild) {
			String[] strings= getFullBuildDialogStrings(fProject == null);
			if (strings != null) {
				MessageDialog dialog= new MessageDialog(getShell(), strings[0], null, strings[1], MessageDialog.QUESTION, new String[] { IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL, IDialogConstants.CANCEL_LABEL }, 2);
				int res= dialog.open();
				if (res == 0) {
					doBuild= true;
				} else if (res != 1) {
					return false; 
				}
			}
		}
		if (container != null) {
			
			if (doBuild) {