Fix #1853

Author: cowtowncoder

release-notes/CREDITS

@@ -733,3 +733,8 @@ Pier-Luc Whissell (pwhissell@github):
   * Reported #1673: Serialising generic value classes via Reference Types (like Optional) fails
     to include type information
    (2.9.4)
+
+Alexander Skvortcov (askvortcov@github)
+  * Reported #1853: Deserialise from Object (using Creator methods) returns field name
+    instead of value
+   (2.9.4)

release-notes/VERSION-2.x

@@ -10,6 +10,8 @@ Project: jackson-databind
  (reported by Pier-Luc W)
 #1729: Integer bounds verification when calling `TokenBuffer.getIntValue()`
  (reported by Kevin G)
+#1853: Deserialise from Object (using Creator methods) returns field name instead of value
+ (reported by Alexander S)
 #1854: NPE deserializing collection with `@JsonCreator` and `ACCEPT_CASE_INSENSITIVE_PROPERTIES`
  (reported by rue-jw@github)
 #1855: Blacklist for more serialization gadgets (dbcp/tomcat, spring)

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

@@ -635,6 +635,18 @@ protected void _addExplicitDelegatingCreator(DeserializationContext ctxt,
             ctxt.reportBadTypeDefinition(beanDesc,
                     "No argument left as delegating for Creator %s: exactly one required", candidate);
         }
+        // 17-Jan-2018, tatu: as per [databind#1853] need to ensure we will distinguish
+        //   "well-known" single-arg variants (String, int/long, boolean) from "generic" delegating...
+        if (argCount == 1) {
+            _handleSingleArgumentCreator(creators, candidate.creator(), true, true);
+            // one more thing: sever link to creator property, to avoid possible later
+            // problems with "unresolved" constructor property
+            BeanPropertyDefinition paramDef = candidate.propertyDef(0);
+            if (paramDef != null) {
+                ((POJOPropertyBuilder) paramDef).removeConstructors();
+            }
+            return;
+        }
         creators.addDelegatingCreator(candidate.creator(), true, properties, ix);
     }
 
@@ -691,7 +703,7 @@ protected void _addExplicitAnyCreator(DeserializationContext ctxt,
         // Looks like there's bit of magic regarding 1-parameter creators; others simpler:
         if (1 != candidate.paramCount()) {
             // Ok: for delegates, we want one and exactly one parameter without
-            // injection AND  without name
+            // injection AND without name
             int oneNotInjected = candidate.findOnlyParamWithoutInjection();
             if (oneNotInjected >= 0) {
                 // getting close; but most not have name
@@ -945,7 +957,7 @@ private void _checkImplicitlyNamedConstructors(DeserializationContext ctxt,
                 if ((namedCount + injectCount) == argCount) {
                     creators.addPropertyCreator(factory, false, properties);
                 } else if ((explicitNameCount == 0) && ((injectCount + 1) == argCount)) {
-                    // [712] secondary: all but one injectable, one un-annotated (un-named)
+                    // secondary: all but one injectable, one un-annotated (un-named)
                     creators.addDelegatingCreator(factory, false, properties, 0);
                 } else { // otherwise, epic fail
                     ctxt.reportBadTypeDefinition(beanDesc,

src/main/java/com/fasterxml/jackson/databind/deser/impl/CreatorCollector.java

@@ -132,8 +132,7 @@ public void setDefaultCreator(AnnotatedWithParams creator) {
         _creators[C_DEFAULT] = _fixAccess(creator);
     }
 
-    public void addStringCreator(AnnotatedWithParams creator,
-            boolean explicit) {
+    public void addStringCreator(AnnotatedWithParams creator, boolean explicit) {
         verifyNonDup(creator, C_STRING, explicit);
     }
 
@@ -145,13 +144,11 @@ public void addLongCreator(AnnotatedWithParams creator, boolean explicit) {
         verifyNonDup(creator, C_LONG, explicit);
     }
 
-    public void addDoubleCreator(AnnotatedWithParams creator,
-            boolean explicit) {
+    public void addDoubleCreator(AnnotatedWithParams creator, boolean explicit) {
         verifyNonDup(creator, C_DOUBLE, explicit);
     }
 
-    public void addBooleanCreator(AnnotatedWithParams creator,
-            boolean explicit) {
+    public void addBooleanCreator(AnnotatedWithParams creator, boolean explicit) {
         verifyNonDup(creator, C_BOOLEAN, explicit);
     }
 
@@ -171,7 +168,8 @@ public void addDelegatingCreator(AnnotatedWithParams creator,
     }
 
     public void addPropertyCreator(AnnotatedWithParams creator,
-            boolean explicit, SettableBeanProperty[] properties) {
+            boolean explicit, SettableBeanProperty[] properties)
+    {
         if (verifyNonDup(creator, C_PROPS, explicit)) {
             // Better ensure we have no duplicate names either...
             if (properties.length > 1) {

src/test/java/com/fasterxml/jackson/databind/deser/creators/TestCreators1853.java

@@ -0,0 +1,53 @@
+package com.fasterxml.jackson.databind.deser.creators;
+
+import com.fasterxml.jackson.annotation.*;
+
+import com.fasterxml.jackson.databind.*;
+
+// Reproduction for [databind#1853], problem with delegating creator,
+// but only explicit case
+public class TestCreators1853 extends BaseMapTest
+{
+    public static class Product {
+        String name;
+
+        public Object other, errors;
+        
+        @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+        public Product(@JsonProperty("name") String name) {
+            this.name = "PROP:" + name;
+        }
+
+        @JsonCreator(mode = JsonCreator.Mode.DELEGATING)
+        public static Product from(String name){
+            return new Product(false, "DELEG:"+name);
+        }
+
+        private Product(boolean bogus, String name) {
+            this.name = name;
+        }
+
+        @JsonValue
+        public String getName(){
+            return name;
+        }
+    }
+
+    private static final String EXAMPLE_DATA = "{\"name\":\"dummy\",\"other\":{},\"errors\":{}}";
+
+    private final ObjectMapper MAPPER = newObjectMapper();
+
+    public void testSerialization() throws Exception {
+        assertEquals(quote("testProduct"),
+                MAPPER.writeValueAsString(new Product(false, "testProduct")));
+    }
+
+    public void testDeserializationFromObject() throws Exception {
+        assertEquals("PROP:dummy", MAPPER.readValue(EXAMPLE_DATA, Product.class).getName());
+    }
+
+    public void testDeserializationFromString() throws Exception {
+        assertEquals("DELEG:testProduct",
+                MAPPER.readValue(quote("testProduct"), Product.class).getName());
+    }
+}