Question

Next line sometimes is corrupting xml file and creating a zero length xml, when OutOfMemoryException has been thrown. How to prevent file corruption?

xmlDoc.Save(filename)

Save-Exception of type ‘System.OutOfMemoryException’ was thrown.
Save-at System.IO.FileStream.Write(Byte[] array, Int32 offset, Int32
count) at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean
flushEncoder) at System.IO.StreamWriter.Write(Char value) at
System.Xml.XmlTextWriter.Indent(Boolean beforeEndElement) at
System.Xml.XmlTextWriter.AutoComplete(Token token) at
System.Xml.XmlTextWriter.WriteStartElement(String prefix, String
localName, String ns) at
System.Xml.XmlDOMTextWriter.WriteStartElement(String prefix, String
localName, String ns) at System.Xml.XmlElement.WriteTo(XmlWriter w)
at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at
System.Xml.XmlElement.WriteTo(XmlWriter w) at
System.Xml.XmlDocument.WriteContentTo(XmlWriter xw) at
System.Xml.XmlDocument.WriteTo(XmlWriter w) at
System.Xml.XmlDocument.Save(String filename) at
MainOptions.Save(String filename, ItemOptions options)

Answer 1

You’re overwritting the file as you save it to filename.
To backup the old copy,

• move it to another location (like filename.bak) before saving and
  delete it afterwards or
• save the new file as another file (like filename.new) and rename it on success

When an exception is thrown, you can easily restore the old/previous version of the xml file.