HttpRequestSnippet incorrectly infers Content-Type for POST/PUT/PATCH requests without a body

[banseok1216]

Problem

HttpRequestSnippet currently inserts a 'Content-Type: application/x-www-form-urlencoded' header in the following scenario:

• The method is POST/PUT/PATCH
• No Content-Type header is provided
• No request body
• No request parameters included in the URI

Example of the generated documentation:

POST /foo HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: localhost

However, the actual request had no Content-Type header, and Spring MVC would also receive it without one.
Since HTTP does not define a default media type and Spring does not infer one, this results in documentation that doesn’t match the real request.

Expected behavior

When a request has:

• no Content-Type header
• no body
• no multipart parts

REST Docs should not add a Content-Type header automatically.

Only Content-Type values explicitly present in the request should be documented.

Minimal reproduction

new HttpRequestSnippet().document(
    operationBuilder
        .request("http://localhost/foo")
        .method("POST")
        .build()
);

Expected output:

POST /foo HTTP/1.1
Host: localhost

Actual output:

POST /foo HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: localhost

Why this matters

• REST Docs should document the actual HTTP request sent by the client.
• Spring MVC does not assume application/x-www-form-urlencoded when no Content-Type is provided.
• Injecting a Content-Type that never existed can lead to misleading or incorrect API documentation.

Related issues

This problem appears to be related to the behavior described in:

• HTTP request snippet for a PUT request with a query string duplicates the string's parameters in a form URL encoded body #763