javax.tools.JavaCompilerTool.run( (JavaFileManager) null, , , ) doesn't use default JavaFileManager

test fragment:

        CommonServices.FileManagerWrapper a_fmw = new CommonServices.FileManagerWrapper( a_fm, new CommonServices.Tracer( ref ) );

        a_fmw.clearMarksCount();
        // set default (custom) file manager
        a_tool.setFileManager( a_fmw );
        // run 'run'
        try {
            boolean a_res = a_tool.run((JavaFileManager) null, null, ref, a_validSource);
        } catch (RuntimeException a_e) {
            return Status.failed( String.format( "exception during 'JavaCompilerTool.run' ('%s')\n", a_e.getMessage() ) );
        }
        if( a_fmw.marksCount() == 0 )
            return Status.failed( "default JavaFileManager wasn't used (directly passed one was used)\n" );

CommonServices.FileManagerWrapper & Markable classes:

    public static class Markable {
        public void clearMarksCount() { m_marksCount = 0; }
        public int marksCount() { return m_marksCount; }
        protected void mark() { m_marksCount++; }

        private int m_marksCount = 0;
    }

    public static class FileManagerWrapper extends Markable implements JavaFileManager {
        public FileManagerWrapper( JavaFileManager p_fm, Tracer p_tracer ) {
            m_fm = p_fm;
            m_tracer = p_tracer;
        }

        public void close() throws IOException {
            mark(); m_fm.close();
        }
        public void flush() throws IOException {
            mark(); m_fm.flush();
        }
        public JavaFileObject getFileForInput(String name) throws IOException {
            mark();
            return m_fm.getFileForInput(name);
        }
        public JavaFileObject getFileForOutput(String classname, JavaFileObject.Kind kind, JavaFileObject sibling) throws IOException {
            mark();
            return m_fm.getFileForOutput(classname, kind, sibling);
        }
        public JavaFileObject getFileForOutput(String filename, String location, String pkg) throws IOException {
            mark();
            return m_fm.getFileForOutput(filename, location, pkg);
        }
        public Iterable<JavaFileObject> list(String packageName, Set<JavaFileObject.Kind> kinds) throws IOException {
            mark();
            return m_fm.list(packageName, kinds);
        }
        public void setLocation(String location, String path) {
            mark();
            m_fm.setLocation(location, path);
        }

        private JavaFileManager m_fm;
        private Tracer m_tracer;
    }