Bug 53201 NPE when re-running newly generated javadoc.xml
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javadocexport/JavadocOptionsManager.java
toolArgs.add("-d"); 
			toolArgs.add(fDestination);
		} else {
			if (fAdditionalParams.length() + fVMParams.length() != 0) {
				ExecutionArguments tokens= new ExecutionArguments(fVMParams, fAdditionalParams); 
				String[] vmArgsArray= tokens.getVMArgumentsArray();
				for (int i= 0; i < vmArgsArray.length; i++) {
					vmArgs.add(vmArgsArray[i]);
				}
				
				String[] argsArray= tokens.getProgramArgumentsArray();
				for (int i= 0; i < argsArray.length; i++) {
					toolArgs.add(argsArray[i]);
				}
			}
			toolArgs.add("-doclet"); 
			toolArgs.add(fDocletname);
			toolArgs.add("-docletpath"); 
			toolArgs.add(fDocletpath);
		}
		toolArgs.add("-sourcepath"); 
		toolArgs.add(flatPathList(fSourcepath));
		toolArgs.add("-classpath"); 
		toolArgs.add(flatPathList(fClasspath));
		toolArgs.add("-" + fAccess); 
		if (fFromStandard) {
			if (fJDK14Mode) {
				toolArgs.add("-source"); 
				toolArgs.add("1.4"); 
			}