Fix #4724 (delegating creator, Records) (#4740)

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -1670,6 +1670,9 @@ Antti Lampinen (arlampin@github)
   * Reported #3897: 2.15.0 breaks deserialization when POJO/Record only has a single field
     and is marked `Access.WRITE_ONLY`
    (2.15.1)
+  * Reported #4724: Deserialization behavior change with Records, `@JsonCreator` and
+   `@JsonValue` between 2.17 and 2.18
+   (2.18.1)
 
 Dmitry Bolotin (dbolotin@github)
   * Reported #1172: `@JsonView` doesn't work with `@JsonCreator`

release-notes/VERSION-2.x

@@ -10,6 +10,9 @@ Project: jackson-databind
  (reported by @MaximValeev)
  (fix by Joo-Hyuk K)
 #4718: Should not fail on trying to serialize `java.time.DateTimeException`
+#4724: Deserialization behavior change with Records, `@JsonCreator` and
+  `@JsonValue` between 2.17 and 2.18
+ (reported by Antti L)
 
 2.18.0 (26-Sep-2024)
 

src/main/java/com/fasterxml/jackson/databind/introspect/POJOPropertiesCollector.java

@@ -689,17 +689,22 @@ protected void _addCreators(Map<String, POJOPropertyBuilder> props)
             _addCreatorsWithAnnotatedNames(creators, constructors, defaultCreator);
         }
 
-        // But if no annotation-based Creators found, find/use Primary Creator
+        // But if no annotation-based Creators found, find/use Default Creator
         // detected earlier, if any
         if (defaultCreator != null) {
-            if (!creators.hasPropertiesBased()) {
-                // ... but only process if still included as a candidate
-                if (constructors.remove(defaultCreator)
-                        || factories.remove(defaultCreator)) {
-                    // But wait! Could be delegating
-                    if (_isDelegatingConstructor(defaultCreator)) {
+            // ... but only process if still included as a candidate
+            if (constructors.remove(defaultCreator)
+                    || factories.remove(defaultCreator)) {
+                // and then consider delegating- vs properties-based
+                if (_isDelegatingConstructor(defaultCreator)) {
+                    // 08-Oct-2024, tatu: [databind#4724] Only add if no explicit
+                    //    candidates added
+                    if (!creators.hasDelegating()) {
+                        // ... not technically explicit but simpler this way
                         creators.addExplicitDelegating(defaultCreator);
-                    } else {
+                    }
+                } else { // default creator is properties-based
+                    if (!creators.hasPropertiesBased()) {
                         creators.setPropertiesBased(_config, defaultCreator, "Primary");
                     }
                 }

src/main/java/com/fasterxml/jackson/databind/introspect/PotentialCreators.java

@@ -56,6 +56,11 @@ public void setImplicitDelegating(List<PotentialCreator> implicitConstructors,
     /**********************************************************************
      */
 
+    // @since 2.18.1
+    public boolean hasDelegating() {
+        return (explicitDelegating != null) && !explicitDelegating.isEmpty();
+    }
+    
     public boolean hasPropertiesBased() {
         return (propertiesBased != null);
     }

src/test-jdk17/java/com/fasterxml/jackson/databind/tofix/RecordJsonCreatorAndJsonValue4724Test.java

@@ -1,24 +1,23 @@
 package com.fasterxml.jackson.databind.tofix;
 
+import org.junit.jupiter.api.Test;
+
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
-import com.fasterxml.jackson.databind.testutil.failure.JacksonTestFailureExpected;
-
-import org.junit.jupiter.api.Test;
 
 // [databind#4724] Deserialization behavior change with Java Records, JsonCreator and JsonValue between 2.17.2 => 2.18.0
 public class RecordJsonCreatorAndJsonValue4724Test
     extends DatabindTestUtil
 {
-
     public record Something(String value) {
         public Something {
             if (value == null || value.isEmpty()) {
                 throw new IllegalArgumentException("Value cannot be null or empty");
             }
         }
 
+        // should be considered Delegating due to @JsonValue later on
         @JsonCreator
         public static Something of(String value) {
             if (value.isEmpty()) {
@@ -34,10 +33,8 @@ public String toString() {
         }
     }
 
-    @JacksonTestFailureExpected
     @Test
     void deserialization() throws Exception {
         newJsonMapper().readValue("\"\"", Something.class);
     }
-
 }