Fixes #145: use correct delegation for `GuavaOptionalDeserializer.get…

…Empty()` (#146)

guava/src/main/java/com/fasterxml/jackson/datatype/guava/deser/GuavaOptionalDeserializer.java

@@ -47,7 +47,9 @@ public Optional<?> getNullValue(DeserializationContext ctxt) throws JsonMappingE
 
     @Override
     public Object getEmptyValue(DeserializationContext ctxt) throws JsonMappingException {
-        return getEmptyValue(ctxt);
+        // 11-Feb-2024, tatu: [datatypes-collections#145] Should delegate
+        //   to use "null value" (same as default of `ReferenceTypeDeserializer`)
+        return getNullValue(ctxt);
     }
 
     @Override

guava/src/test/java/com/fasterxml/jackson/datatype/guava/optional/OptionalFromEmptyTest.java

@@ -1,18 +1,42 @@
 package com.fasterxml.jackson.datatype.guava.optional;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonSetter;
+import com.fasterxml.jackson.annotation.Nulls;
+
 import com.fasterxml.jackson.core.type.TypeReference;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.datatype.guava.ModuleTestBase;
+
 import com.google.common.base.Optional;
 
 public class OptionalFromEmptyTest extends ModuleTestBase
 {
+    static class OptionalBeanWithEmpty {
+        protected Optional<String> _value;
+
+        @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+        public OptionalBeanWithEmpty(@JsonProperty("value")
+            @JsonSetter(nulls = Nulls.AS_EMPTY) Optional<String> ref) {
+            _value = ref;
+        }
+    }
+
     private final ObjectMapper MAPPER = mapperWithModule();
 
     // [datatype-guava#48]
     public void testDeserNull() throws Exception {
         Optional<?> value = MAPPER.readValue("\"\"", new TypeReference<Optional<Integer>>() {});
         assertEquals(false, value.isPresent());
     }
+
+    // [datatypes-collections#145]
+    public void testDeserEmptyViaConstructor() throws Exception {
+        OptionalBeanWithEmpty bean = MAPPER.readValue("{}",
+                OptionalBeanWithEmpty.class);
+        assertNotNull(bean._value);
+        assertFalse(bean._value.isPresent());
+    }
 }

release-notes/VERSION-2.x

@@ -16,6 +16,10 @@ Active Maintainers:
 === Releases ===
 ------------------------------------------------------------------------
 
+2.16.2 (not yet released)
+
+#145: `GuavaOptionalDeserializer.getEmptyValue()` should not call itself recursively
+
 2.16.1 (24-Dec-2023)
 
 No changes since 2.16.0