Fixed problem in CollectionDeserializer where _nullProvider was not used if it was not JsonToken.VALUE_NULL (#5140)

Author: k163377

release-notes/CREDITS-2.x

@@ -1860,6 +1860,9 @@ wrongwrong (@k163377)
    `@JsonDeserialize(keyUsing = ...)` is overwritten by the `KeyDeserializer`
     specified in the `ObjectMapper`.
   (2.18.3)
+ * Contributed fix for #5139: In `CollectionDeserializer`, `JsonSetter.contentNulls`
+   is sometimes ignored
+  (2.19.1)
 
 Bernd Ahlers (@bernd)
  * Reported #4742: Deserialization with Builder, External type id, `@JsonCreator` failing

release-notes/VERSION-2.x

@@ -4,6 +4,11 @@ Project: jackson-databind
 === Releases === 
 ------------------------------------------------------------------------
 
+2.19.1 (not yet released)
+
+#5139: In `CollectionDeserializer`, `JsonSetter.contentNulls` is sometimes ignored
+ (contributed by @wrongwrong)
+
 2.19.0 (24-Apr-2025)
 
 #1467: Support `@JsonUnwrapped` with `@JsonCreator`

src/main/java/com/fasterxml/jackson/databind/deser/std/CollectionDeserializer.java

@@ -353,16 +353,21 @@ protected Collection<Object> _deserializeFromArray(JsonParser p, Deserialization
                     if (_skipNullValues) {
                         continue;
                     }
-                    value = _nullProvider.getNullValue(ctxt);
-                } else if (_valueTypeDeserializer == null) {
-                    value = _valueDeserializer.deserialize(p, ctxt);
+                    value = null;
                 } else {
-                    value = _valueDeserializer.deserializeWithType(p, ctxt, _valueTypeDeserializer);
+                    value = _deserializeNoNullChecks(p, ctxt);
                 }
+
                 if (value == null) {
-                    _tryToAddNull(p, ctxt, result);
-                    continue;
+                    value = _nullProvider.getNullValue(ctxt);
+
+                    // _skipNullValues is checked by _tryToAddNull.
+                    if (value == null) {
+                        _tryToAddNull(p, ctxt, result);
+                        continue;
+                    }
                 }
+
                 result.add(value);
 
                 /* 17-Dec-2017, tatu: should not occur at this level...
@@ -398,6 +403,7 @@ protected final Collection<Object> handleNonArray(JsonParser p, DeserializationC
         if (!canWrap) {
             return (Collection<Object>) ctxt.handleUnexpectedToken(_containerType, p);
         }
+
         Object value;
 
         try {
@@ -406,16 +412,19 @@ protected final Collection<Object> handleNonArray(JsonParser p, DeserializationC
                 if (_skipNullValues) {
                     return result;
                 }
-                value = _nullProvider.getNullValue(ctxt);
-            } else if (_valueTypeDeserializer == null) {
-                value = _valueDeserializer.deserialize(p, ctxt);
+                value = null;
             } else {
-                value = _valueDeserializer.deserializeWithType(p, ctxt, _valueTypeDeserializer);
+                value = _deserializeNoNullChecks(p, ctxt);
             }
-            // _skipNullValues is checked by _tryToAddNull.
+
             if (value == null) {
-                _tryToAddNull(p, ctxt, result);
-                return result;
+                value = _nullProvider.getNullValue(ctxt);
+
+                // _skipNullValues is checked by _tryToAddNull.
+                if (value == null) {
+                    _tryToAddNull(p, ctxt, result);
+                    return result;
+                }
             }
         } catch (Exception e) {
             boolean wrap = ctxt.isEnabled(DeserializationFeature.WRAP_EXCEPTIONS);
@@ -447,18 +456,21 @@ protected Collection<Object> _deserializeWithObjectId(JsonParser p, Deserializat
         while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
             try {
                 Object value;
+
                 if (t == JsonToken.VALUE_NULL) {
                     if (_skipNullValues) {
                         continue;
                     }
-                    value = _nullProvider.getNullValue(ctxt);
-                } else if (_valueTypeDeserializer == null) {
-                    value = _valueDeserializer.deserialize(p, ctxt);
+                    value = null;
                 } else {
-                    value = _valueDeserializer.deserializeWithType(p, ctxt, _valueTypeDeserializer);
+                    value = _deserializeNoNullChecks(p, ctxt);
                 }
-                if (value == null && _skipNullValues) {
-                    continue;
+
+                if (value == null) {
+                    value = _nullProvider.getNullValue(ctxt);
+                    if (value == null && _skipNullValues) {
+                        continue;
+                    }
                 }
                 referringAccumulator.add(value);
             } catch (UnresolvedForwardReference reference) {
@@ -475,6 +487,22 @@ protected Collection<Object> _deserializeWithObjectId(JsonParser p, Deserializat
         return result;
     }
 
+    /**
+     * Deserialize the content of the collection.
+     * If _valueTypeDeserializer is null, use _valueDeserializer.deserialize; if non-null,
+     * use _valueDeserializer.deserializeWithType to deserialize value.
+     * This method only performs deserialization and does not consider _skipNullValues, _nullProvider, etc.
+     * @since 2.19.1
+     */
+    protected Object _deserializeNoNullChecks(JsonParser p,DeserializationContext ctxt)
+        throws IOException
+    {
+        if (_valueTypeDeserializer == null) {
+            return _valueDeserializer.deserialize(p, ctxt);
+        }
+        return _valueDeserializer.deserializeWithType(p, ctxt, _valueTypeDeserializer);
+    }
+
     /**
      * {@code java.util.TreeSet} (and possibly other {@link Collection} types) does not
      * allow addition of {@code null} values, so isolate handling here.

src/test/java/com/fasterxml/jackson/databind/deser/jdk/CollectionDeserializer5139Test.java

@@ -0,0 +1,54 @@
+package com.fasterxml.jackson.databind.deser.jdk;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+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.databind.exc.InvalidNullException;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+// For [databind#5139]
+public class CollectionDeserializer5139Test
+{
+    static class Dst {
+        private List<Integer> list;
+
+        public List<Integer> getList() {
+            return list;
+        }
+
+        public void setList(List<Integer> list) {
+            this.list = list;
+        }
+    }
+
+    @Test
+    public void nullsFailTest() {
+        ObjectMapper mapper = JsonMapper.builder()
+                .defaultSetterInfo(JsonSetter.Value.forContentNulls(Nulls.FAIL))
+                .build();
+
+        assertThrows(
+                InvalidNullException.class,
+                () -> mapper.readValue("{\"list\":[\"\"]}", new TypeReference<Dst>(){})
+        );
+    }
+
+    @Test
+    public void nullsSkipTest() throws Exception {
+        ObjectMapper mapper = JsonMapper.builder()
+                .defaultSetterInfo(JsonSetter.Value.forContentNulls(Nulls.SKIP))
+                .build();
+
+        Dst dst = mapper.readValue("{\"list\":[\"\"]}", new TypeReference<Dst>() {});
+
+        assertTrue(dst.getList().isEmpty());
+    }
+}