Update release notes wrt #3481

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -30,6 +30,9 @@ Project: jackson-databind
  (reported by Deniz H)
 #3476: Implement `JsonNodeFeature.WRITE_NULL_PROPERTIES` to allow skipping
   JSON `null` values on writing
+#3481: Filter method only got called once if the field is null when using
+  `@JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = SomeFieldFilter.class)`
+ (contributed by AmiDavidW@github)
 #3497: Deserialization of Throwables with PropertyNamingStrategy does not work
 
 2.13.4 (not yet released)

src/main/java/com/fasterxml/jackson/databind/ser/BeanPropertyWriter.java

@@ -689,8 +689,10 @@ public void serializeAsField(Object bean, JsonGenerator gen,
                 : _accessorMethod.invoke(bean, (Object[]) null);
 
         // Null handling is bit different, check that first
-        if (value == null ) {
-            if(_suppressableValue != null && _suppressableValue.equals(value)) {
+        if (value == null) {
+            // 20-Jun-2022, tatu: Defer checking of null, see [databind#3481]
+            if((_suppressableValue != null)
+                    && prov.includeFilterSuppressNulls(_suppressableValue)) {
                 return;
             }
             if (_nullSerializer != null) {

src/main/java/com/fasterxml/jackson/databind/ser/DefaultSerializerProvider.java

@@ -165,11 +165,11 @@ public boolean includeFilterSuppressNulls(Object filter) throws JsonMappingExcep
         // But just in case, let's handle unexpected (from our perspective) problems explicitly
         try {
             return filter.equals(null);
-        } catch (Throwable t) {
+        } catch (Exception e) {
             String msg = String.format(
 "Problem determining whether filter of type '%s' should filter out `null` values: (%s) %s",
-filter.getClass().getName(), t.getClass().getName(), ClassUtil.exceptionMessage(t));
-            reportBadDefinition(filter.getClass(), msg, t);
+filter.getClass().getName(), e.getClass().getName(), ClassUtil.exceptionMessage(e));
+            reportBadDefinition(filter.getClass(), msg, e);
             return false; // never gets here
         }
     }

src/test/java/com/fasterxml/jackson/databind/ser/filter/JsonIncludeCustomTest.java

@@ -132,7 +132,9 @@ public void testBrokenFilter() throws Exception
             String json = MAPPER.writeValueAsString(new BrokenBean(null));
             fail("Should not pass, produced: "+json);
         } catch (JsonMappingException e) {
-            verifyException(e, "while trying to invoke the method java.lang.Object.toString() of a null object loaded from local variable 'other'");
+            // 20-Jun-2022, tatu: Actual message seems to vary across JDKs...
+            verifyException(e, "Problem determining whether filter");
+            verifyException(e, "should filter out `null` values");
         }
     }
 }