GH-39865 added support for MethodValidationResult to DefaultErrorAttributes but it filters the list errors published in the result and used for counting to instances of ObjectError.

With a method signature (in a RestController) of e.g. public void method(@PathVariable @Pattern(regexp = "^a.*") String parameter), this results in

• message = "Validation failed for method='public void <class>.method(java.lang.String)'. Error count: 0"
• errors = []

This is due to the fact, that the MethodValidationResult generated by MethodValidationAdapter will contain instances of ParameterValidationResult that have resolvable errors of type DefaultMessageSourceResolvable (and not ObjectError).

Spring Boot 3.3.1
Spring Framework 6.1.10