Schema updates for #4339

Author: mikekistler

src/schemas/validation/meta.yaml

@@ -29,6 +29,8 @@ $defs:
         additionalProperties:
           type: string
         type: object
+      defaultMapping:
+        type: object
       propertyName:
         type: string
     required:

tests/schema/pass/mega.yaml

@@ -55,6 +55,9 @@ components:
                   propertyName: type
                   mapping:
                     foo: Foo
+                  defaultMapping:
+                    not:
+                      required: ['type']
                   x-extension: true
                 anyOf:
                 - $ref: "#/components/schemas/Foo"