Merge branch '2.19'

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -41,6 +41,8 @@ Project: jackson-databind
 #4867: Add `Optional<JsonNode> JsonNode.asOptional()` convenience method
  (fix by Joo-Hyuk K)
 #4869: Add `JsonNode.values()` to replace `elements()`
+#4896: Coercion shouldn't be necessary for Enums specifying an empty string
+ (reported by @joaocanaverde-blue)
 
 2.18.3 (not yet released)
 

src/main/java/tools/jackson/databind/introspect/JacksonAnnotationIntrospector.java

@@ -167,7 +167,7 @@ public boolean isAnnotationBundle(Annotation ann) {
     /**********************************************************************
      */
 
-    @Override // since 2.16
+    @Override
     public String[] findEnumValues(MapperConfig<?> config, AnnotatedClass annotatedClass,
             Enum<?>[] enumValues, String[] names)
     {
@@ -176,7 +176,9 @@ public String[] findEnumValues(MapperConfig<?> config, AnnotatedClass annotatedC
             JsonProperty property = field.getAnnotation(JsonProperty.class);
             if (property != null) {
                 String propValue = property.value();
-                if (propValue != null && !propValue.isEmpty()) {
+                if (propValue != null) {
+                    // 24-Jan-2025, tatu: [databind#4896] Should not skip "" with enums
+                    // && !propValue.isEmpty()) {
                     enumToPropertyMap.put(field.getName(), propValue);
                 }
             }

src/main/java/tools/jackson/databind/util/CompactStringObjectMap.java

@@ -94,7 +94,8 @@ private final static int findSize(int size)
         return result;
     }
 
-    public Object find(String key) {
+    public Object find(String key)
+    {
         int slot = key.hashCode() & _hashMask;
         int ix = (slot<<1);
         Object match = _hashArea[ix];

src/test/java/tools/jackson/databind/deser/enums/EnumDeserializationTest.java

@@ -202,7 +202,6 @@ public Object deserializeKey(String key, DeserializationContext ctxt) {
         }
     }
 
-
     @JsonDeserialize(using = AnEnumDeserializer.class, keyUsing = AnEnumKeyDeserializer.class)
     public enum LanguageCodeMixin {
     }
@@ -270,6 +269,18 @@ public static Operation3006 forValue(final String idStr) {
         }
     }
 
+    // [databind#4896]
+    enum YesOrNoOrEmpty4896 {
+        @JsonProperty("")
+        EMPTY,
+
+        @JsonProperty("yes")
+        YES,
+
+        @JsonProperty("no")
+        NO;
+    }
+
     /*
     /**********************************************************
     /* Test methods
@@ -816,4 +827,16 @@ public void testEnumFeature_READ_ENUM_KEYS_USING_INDEX_isDisabledByDefault() {
         assertFalse(READER.without(EnumFeature.READ_ENUM_KEYS_USING_INDEX)
             .isEnabled(EnumFeature.READ_ENUM_KEYS_USING_INDEX));
     }
+
+    // [databind#4896]
+    @Test
+    public void testEnumReadFromEmptyString() throws Exception {
+        // First, regular value
+        assertEquals(YesOrNoOrEmpty4896.YES,
+                MAPPER.readerFor(YesOrNoOrEmpty4896.class)
+                    .readValue(q("yes")));
+        assertEquals(YesOrNoOrEmpty4896.EMPTY,
+            MAPPER.readerFor(YesOrNoOrEmpty4896.class)
+                .readValue(q("")));
+    }
 }