System.Configuration.MgmtConfigurationRecord.CopyConfig C# (CSharp) Method

        private void CopyConfig(SectionUpdates declarationUpdates, ConfigDefinitionUpdates definitionUpdates, 
                byte[] buffer, string filename, NamespaceChange namespaceChange, XmlUtilWriter utilWriter) {

            CheckPreamble(ConfigStreamInfo.StreamEncoding.GetPreamble(), utilWriter, buffer);

            using (Stream stream = new MemoryStream(buffer)) {
                using (XmlUtil xmlUtil = new XmlUtil(stream, filename, false)) {
                    // copy up to the <configuration> node
                    XmlTextReader reader = xmlUtil.Reader;
                    reader.WhitespaceHandling = WhitespaceHandling.All;
                    reader.Read();
                    xmlUtil.CopyReaderToNextElement(utilWriter, false);

                    Debug.Assert(reader.NodeType == XmlNodeType.Element && reader.Name == KEYWORD_CONFIGURATION, 
                                 "reader.NodeType == XmlNodeType.Element && reader.Name == KEYWORD_CONFIGURATION");

                    int indent = DEFAULT_INDENT;
                    int configurationElementLinePosition = xmlUtil.TrueLinePosition;
                    bool isEmptyConfigurationElement = reader.IsEmptyElement;

                    // copy <configuration> node
                    // if the node is an empty element, we may need to open it.
                    string configurationStartElement;
                    if (namespaceChange == NamespaceChange.Add) {
                        configurationStartElement = string.Format(
                            CultureInfo.InvariantCulture, FORMAT_CONFIGURATION_NAMESPACE, KEYWORD_CONFIGURATION_NAMESPACE);
                    }
                    else if (namespaceChange == NamespaceChange.Remove) {
                        configurationStartElement = FORMAT_CONFIGURATION;
                    }
                    else {
                        configurationStartElement = null;
                    }

                    bool needsChildren = (declarationUpdates != null || definitionUpdates  != null);
                    string configurationEndElement = xmlUtil.UpdateStartElement(utilWriter, configurationStartElement, needsChildren, configurationElementLinePosition, indent);

                    bool foundConfigSectionsElement = false;
                    if (!isEmptyConfigurationElement) {
                        // copy up to the first element under <configuration>
                        xmlUtil.CopyReaderToNextElement(utilWriter, true);

                        // updateIndent
                        indent = UpdateIndent(indent, xmlUtil, utilWriter, configurationElementLinePosition);

                        if (reader.NodeType == XmlNodeType.Element && reader.Name == KEYWORD_CONFIGSECTIONS) {
                            foundConfigSectionsElement = true;

                            int configSectionsElementLinePosition = xmlUtil.TrueLinePosition;
                            bool isEmptyConfigSectionsElement = reader.IsEmptyElement;

                            // if no updates, copy the entire <configSections> element
                            if (declarationUpdates == null) {
                                xmlUtil.CopyOuterXmlToNextElement(utilWriter, true);
                            }
                            else {
                                // copy <configSections>, and open it if it is an empty element
                                string configSectionsEndElement = xmlUtil.UpdateStartElement(
                                    utilWriter, null, true, configSectionsElementLinePosition, indent);

                                if (!isEmptyConfigSectionsElement) {
                                    // copy to next element under <configSections>, or up to closing </configSections>
                                    xmlUtil.CopyReaderToNextElement(utilWriter, true);

                                    // copy config declarations
                                    CopyConfigDeclarationsRecursive(declarationUpdates, xmlUtil, utilWriter, string.Empty, 
                                            configSectionsElementLinePosition, indent);

                                    Debug.Assert(reader.NodeType == XmlNodeType.EndElement && reader.Name == KEYWORD_CONFIGSECTIONS, 
                                                 "reader.NodeType == XmlNodeType.EndElement && reader.Name == \"KEYWORD_CONFIGSECTIONS\"");
                                }

                                // write declarations not written by above copy
                                if (declarationUpdates.HasUnretrievedSections()) {

                                    // determine the line position of the end element
                                    int endElementLinePosition = 0;
                                    if (configSectionsEndElement == null) {
                                        endElementLinePosition = xmlUtil.TrueLinePosition;
                                    }

                                    // indent a new line
                                    if (!utilWriter.IsLastLineBlank) {
                                        utilWriter.AppendNewLine();
                                    }

                                    WriteUnwrittenConfigDeclarations(declarationUpdates, utilWriter, configSectionsElementLinePosition + indent, indent, false);

                                    // restore spaces to end element
                                    if (configSectionsEndElement == null) {
                                        utilWriter.AppendSpacesToLinePosition(endElementLinePosition);
                                    }
                                }

                                // Copy the </configSections> element
                                if (configSectionsEndElement == null) {
                                    xmlUtil.CopyXmlNode(utilWriter);
                                }
                                else {
                                    // note that configSectionsEndElement already contains the proper indenting
                                    utilWriter.Write(configSectionsEndElement);
                                }

                                // copy up to the next element under <configuration>, or up to closing </configSections>
                                xmlUtil.CopyReaderToNextElement(utilWriter, true);
                            }
                        }
                    }

                    // Write new declarations
                    if (!foundConfigSectionsElement && declarationUpdates != null) {
                        bool skipFirstIndent = reader.Depth > 0 && reader.NodeType == XmlNodeType.Element;
                        int newConfigSectionsLinePosition;
                        if (skipFirstIndent) {
                            newConfigSectionsLinePosition = xmlUtil.TrueLinePosition;
                        }
                        else {
                            newConfigSectionsLinePosition = configurationElementLinePosition + indent;
                        }

                        WriteNewConfigDeclarations(declarationUpdates, utilWriter, newConfigSectionsLinePosition, indent, skipFirstIndent);
                    }

                    if (definitionUpdates != null) {
                        //
                        // Copy sections recursively. In the file we copy we start out at
                        //     location path="." allowOverride="true" inheritInChildApps="true"
                        //
                        bool locationPathApplies = false;
                        LocationUpdates locationUpdates = null;
                        SectionUpdates sectionUpdates = null;
                        if (!IsLocationConfig) {
                            locationPathApplies = true;
                            locationUpdates = definitionUpdates.FindLocationUpdates(true, true);
                            if (locationUpdates != null) {
                                sectionUpdates = locationUpdates.SectionUpdates;
                            }
                        }

                        CopyConfigDefinitionsRecursive(definitionUpdates, xmlUtil, utilWriter, locationPathApplies, 
                            locationUpdates, sectionUpdates, true, string.Empty, configurationElementLinePosition, indent);

                        // Write new config sections from new groups.
                        WriteNewConfigDefinitions(definitionUpdates, utilWriter, configurationElementLinePosition + indent, indent);

#if DBG
                        Debug.Assert(configurationEndElement != null || (reader.NodeType == XmlNodeType.EndElement && reader.Name == KEYWORD_CONFIGURATION),
                                     "configurationEndElement != null || (reader.NodeType == XmlNodeType.EndElement && reader.Name == KEYWORD_CONFIGURATION)");
#endif



#if DBG
                        {
                            foreach (LocationUpdates l in definitionUpdates.LocationUpdatesList) {
                                Debug.Assert(!l.SectionUpdates.HasUnretrievedSections(), "!l.SectionUpdates.HasUnretrievedSections()");
                            }
                        }
#endif
                    }


                    if (configurationEndElement != null) {
                        // If we have to add closing config tag, then do it now
                        // before copying extra whitespace/comments
                        if (!utilWriter.IsLastLineBlank) {
                            utilWriter.AppendNewLine();
                        }

                        utilWriter.Write(configurationEndElement);
                    }

                    //
                    // Copy the remainder of the file, the closing </configuration> node plus any whitespace
                    // and comments
                    //
                    while (xmlUtil.CopyXmlNode(utilWriter)) {
                    }
                }
            }
        }