Merge branch '2.4'

Conflicts:
	src/test/java/com/fasterxml/jackson/databind/introspect/TestMixinMerging.java

Author: cowtowncoder

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

@@ -13,7 +13,7 @@ public final class AnnotatedClass
     extends Annotated
 {
     private final static AnnotationMap[] NO_ANNOTATION_MAPS = new AnnotationMap[0];
-    
+
     /*
     /**********************************************************
     /* Configuration
@@ -654,7 +654,13 @@ protected void _addMethodMixIns(Class<?> targetClass, AnnotatedMethodMap methods
                      * just placeholder, can't be called)
                      */
                 } else {
-                    mixIns.add(_constructMethod(m));
+                    // Well, or, as per [Issue#515], multi-level merge within mixins...
+                    am = mixIns.find(m);
+                    if (am != null) {
+                        _addMixUnders(m, am);
+                    } else {
+                        mixIns.add(_constructMethod(m));
+                    }
                 }
             }
         }

src/test/java/com/fasterxml/jackson/databind/introspect/TestMixinMerging.java

@@ -1,12 +1,50 @@
 package com.fasterxml.jackson.databind.introspect;
 
-import com.fasterxml.jackson.databind.BaseMapTest;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.module.SimpleModule;
 
 public class TestMixinMerging extends BaseMapTest
 {
+    public interface Contact {
+        String getCity();
+    }
+
+    static class ContactImpl implements Contact {
+        public String getCity() { return "Seattle"; }
+    }
+
+    static class ContactMixin implements Contact {
+        @JsonProperty
+        public String getCity() { return null; }
+    }
+
+    public interface Person extends Contact {}
+
+    static class PersonImpl extends ContactImpl implements Person {}
+
+    static class PersonMixin extends ContactMixin implements Person {}
+
+    /*
+    /**********************************************************
+    /* Unit tests
+    /**********************************************************
+     */
+    
     // for [Issue#515]
     public void testDisappearingMixins515() throws Exception
     {
-        // TBI
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.disable(MapperFeature.ALLOW_FINAL_FIELDS_AS_MUTATORS)
+            .disable(MapperFeature.AUTO_DETECT_FIELDS)
+            .disable(MapperFeature.AUTO_DETECT_GETTERS)
+            .disable(MapperFeature.AUTO_DETECT_IS_GETTERS)
+            .disable(MapperFeature.INFER_PROPERTY_MUTATORS);
+        SimpleModule module = new SimpleModule("Test");
+        module.setMixInAnnotation(Person.class, PersonMixin.class);        
+        mapper.registerModule(module);
+
+        assertEquals("{\"city\":\"Seattle\"}", mapper.writeValueAsString(new PersonImpl()));
     }
 }