WCF 3.5 REST - Data member having \r\n replaced with \n

Question

My RESTful WCF 3.5 service accepts an XmlSerialized (as opposed to DataContract serialized) data object which contains a freeform string field.

The client I wrote (which uses HttpWebRequest / HttpWebResponse to interact with the WCF service) sends XML like this:

<product>
    <description>Foo\r\nBar\r\n\r\nFinal line</description>
</product>

(The CR and LF characters are escaped here for legibility, in reality the raw ASCII bytes 0x0A and 0x0D are sent down the wire, as confirmed with Wireshark).

However my WCF service's [OperationContract]-marked methods all report that the Product.Description property has the value "Foo\nBar\n\nFinal line". This happens before any of my code is called.

Somewhere in WCF the \r\n newline characters in strings are being removed and replaced with \n newlines, but I can't see where or why this is happening.

Answer 1

That's actually mandated by the XML specification - http://www.w3.org/TR/REC-xml/#sec-line-ends: "the XML processorMUST behave as if it normalized all line breaks in external parsed entities (including the document entity) on input, before parsing, by translating both the two-character sequence #xD #xA and any #xD that is not followed by #xA to a single #xA character".

If you want the "\r" to be preserved, you must escape it (into 
) before sending it to the server, so that it doesn't get normalized.

<product>
    <description>Foo&#xD;\nBar&#xD;\n&#xD;\nFinal line</description>
</product>

If you're producing this XML with a XmlWriter, you can create one passing a XmlWriterSettings with its NewLineHandling property set to NewLineHandling.Entitize, and this will be done for you.