Add failing test for #1853; improve error checking for StringDeserializer (wrt JsonToken.FIELD_NAME)

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializer.java

@@ -310,7 +310,7 @@ public Object deserializeFromObject(JsonParser p, DeserializationContext ctxt) t
          *   Once again, if we must, we can do more complex handling with buffering,
          *   but let's only do that if and when that becomes necessary.
          */
-        if (_objectIdReader != null && _objectIdReader.maySerializeAsObject()) {
+        if ((_objectIdReader != null) && _objectIdReader.maySerializeAsObject()) {
             if (p.hasTokenId(JsonTokenId.ID_FIELD_NAME)
                     && _objectIdReader.isValidReferencePropertyName(p.getCurrentName(), p)) {
                 return deserializeFromObjectId(p, ctxt);

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

@@ -52,9 +52,13 @@ public String deserialize(JsonParser p, DeserializationContext ctxt) throws IOEx
             return ob.toString();
         }
         // allow coercions for other scalar types
-        String text = p.getValueAsString();
-        if (text != null) {
-            return text;
+        // 17-Jan-2018, tatu: Related to [databind#1853] avoid FIELD_NAME by ensuring it's
+        //   "real" scalar
+        if (t.isScalarValue()) {
+            String text = p.getValueAsString();
+            if (text != null) {
+                return text;
+            }
         }
         return (String) ctxt.handleUnexpectedToken(_valueClass, p);
     }

src/test/java/com/fasterxml/jackson/failing/CreatorFail1853Test.java

@@ -0,0 +1,52 @@
+package com.fasterxml.jackson.failing;
+
+import com.fasterxml.jackson.annotation.*;
+
+import com.fasterxml.jackson.databind.*;
+
+public class CreatorFail1853Test extends BaseMapTest
+{
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public static class Product {
+        String name;
+
+        @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+        public Product(@JsonProperty("name") String name)
+        {
+            this.name = name;
+        }
+
+        @JsonValue
+        public String getName(){
+            return name;
+        }
+
+        @Override
+        public String toString() {
+            return "|~" + name + "~|";
+        }
+
+        @JsonCreator(mode = JsonCreator.Mode.DELEGATING)
+        public static Product from(String name){
+            return new Product(name);
+        }
+    }
+
+    private static final String EXAMPLE_DATA = "{\"name\":\"dummy\",\"other\":{},\"errors\":{}}";
+    private static final String TEST_PRODUCT_JSON = "\"testProduct\"";
+
+    private ObjectMapper objectMapper = new ObjectMapper();
+
+    public void testSerialization() throws Exception {
+        assertEquals(TEST_PRODUCT_JSON,
+                objectMapper.writeValueAsString(new Product("testProduct")));
+    }
+
+    public void testDeserializationFromObject() throws Exception {
+        assertEquals("dummy", objectMapper.readValue(EXAMPLE_DATA, Product.class).getName());
+    }
+
+    public void testDeserializationFromString() throws Exception {
+        assertEquals("testProduct", objectMapper.readValue(TEST_PRODUCT_JSON, Product.class).getName());
+    }
+}