When JWT value contains dot notation (e.g., user.name) to access nested properties, the DefaultJwtConvertStrategy.addHeader() method adds HTTP headers twice.

Cause:

if (converter.getJwtVal().contains(".")) {
    headers.add(headerVal, parse(...)); // adds correct value
}
headers.add(headerVal, body.get(jwtVal)); // always executes, adds null

Result:

Expected: username: ["john"]
Actual: username: ["john", "null"]

Make sure that:

• You have read the contribution guidelines.
• You submit test cases (unit or integration tests) that back your changes.
• Your local test passed ./mvnw clean install -Dmaven.javadoc.skip=true.