add test and change speculative fix

Author: pjfanning

src/main/java/tools/jackson/databind/ser/BasicSerializerFactory.java

@@ -313,7 +313,7 @@ protected final ValueSerializer<?> findSerializerByPrimaryType(SerializationCont
 
         if (type.isTypeOrSubTypeOf(Number.class)) {
             JsonFormat.Value format = _calculateEffectiveFormat(ctxt,
-                    beanDescRef, type.getRawClass(), formatOverrides);
+                    beanDescRef, Number.class, formatOverrides);
 
             // 21-May-2014, tatu: Couple of alternatives actually
             switch (format.getShape()) {

src/main/java/tools/jackson/databind/ser/BeanSerializerFactory.java

@@ -161,6 +161,9 @@ public ValueSerializer<Object> createSerializer(SerializationContext ctxt, JavaT
                 beanDescRef = ctxt.lazyIntrospectBeanDescription(type);
             }
         }
+        if (formatOverrides == null) {
+            formatOverrides = _calculateEffectiveFormat(ctxt, beanDescRef, type.getRawClass(), JsonFormat.Value.empty());
+        }
         // Slight detour: do we have a Converter to consider?
         Converter<Object,Object> conv = config.findSerializationConverter(beanDescRef.getClassInfo());
         if (conv != null) { // yup, need converter

src/test/java/tools/jackson/databind/ser/jdk/NumberSerTest.java

@@ -232,10 +232,19 @@ public void testCustomSerializationBigDecimalAsNumber() throws Exception {
         assertEquals(a2q("{'value':2.0}"), mapper.writeValueAsString(new BigDecimalHolder("2")));
     }
 
+    @Test
+    public void testConfigOverrideJdkNumber() throws Exception {
+        JsonMapper mapper = jsonMapperBuilder().withConfigOverride(BigDecimal.class,
+                c -> c.setFormat(JsonFormat.Value.forShape(JsonFormat.Shape.STRING)))
+                .build();
+        String value = mapper.writeValueAsString(new BigDecimal("123.456"));
+        assertEquals(a2q("'123.456'"), value);
+    }
+
     @Test
     public void testConfigOverrideNonJdkNumber() throws Exception {
         JsonMapper mapper = jsonMapperBuilder().withConfigOverride(MyBigDecimal.class,
-                c -> c.setFormat(JsonFormat.Value.forShape(JsonFormat.Shape.STRING)))
+                        c -> c.setFormat(JsonFormat.Value.forShape(JsonFormat.Shape.STRING)))
                 .build();
         String value = mapper.writeValueAsString(new MyBigDecimal("123.456"));
         assertEquals(a2q("'123.456'"), value);