# File lib/maruku/input/parse_block.rb, line 206
        def read_xml_instruction(src, output)
                m = /^\s*<\?((\w+)\s*)?(.*)$/.match src.shift_line
                raise "BugBug" if not m
                target = m[2] || ''
                code = m[3]
                until code =~ /\?>/
                        code += "\n"+src.shift_line
                end
                if not code =~ (/\?>\s*$/)
                        garbage = (/\?>(.*)$/.match(code))[1]
                        maruku_error "Trailing garbage on last line: #{garbage.inspect}:\n"+
                                add_tabs(code, 1, '|'), src
                end
                code.gsub!(/\?>\s*$/, '')
                
                if target == 'mrk' && MaRuKu::Globals[:unsafe_features]
                        result = safe_execute_code(self, code)       
                        if result
                                if result.kind_of? String
                                        raise "Not expected"
                                else
                                        output.push(*result)
                                end
                        end
                else
                        output.push md_xml_instr(target, code)
                end
        end