Add a test for #2787, partial fix (no more NPE, now fails otherwise)

2 files changed, 43 insertions, 1 deletions

diff --git a/src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedFieldCollector.java b/src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedFieldCollector.java
index 0dba88bba..202d63e34 100644
--- a/src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedFieldCollector.java
+++ b/src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedFieldCollector.java
@@ -81,7 +81,7 @@ public class AnnotatedFieldCollector
             fields.put(f.getName(), b);
         }
         // And then... any mix-in overrides?
-        if (_mixInResolver != null) {
+        if ((fields != null) && (_mixInResolver != null)) {
             Class<?> mixin = _mixInResolver.findMixInClassFor(cls);
             if (mixin != null) {
                 _addFieldMixIns(mixin, cls, fields);
diff --git a/src/test/java/com/fasterxml/jackson/failing/EnumDeserialization2787Test.java b/src/test/java/com/fasterxml/jackson/failing/EnumDeserialization2787Test.java
new file mode 100644
index 000000000..9ade19da0
--- /dev/null
+++ b/src/test/java/com/fasterxml/jackson/failing/EnumDeserialization2787Test.java
@@ -0,0 +1,42 @@
+package com.fasterxml.jackson.failing;
+
+import com.fasterxml.jackson.annotation.*;
+
+import com.fasterxml.jackson.databind.*;
+
+public class EnumDeserialization2787Test extends BaseMapTest
+{
+    // [databind#2787]
+    static enum SomeEnum2787 {
+        none,
+        tax10,
+        tax20
+    }
+
+    static enum  SomeEnumMixin2787 {
+        @JsonProperty("zero")
+        none,
+        @JsonProperty("TypTyp")
+        tax10,
+        @JsonProperty("PytPyt")
+        tax20
+    }
+
+    /*
+    /**********************************************************
+    /* Test methods
+    /**********************************************************
+     */
+
+    protected final ObjectMapper MAPPER = newJsonMapper();
+
+    // [databind#2787]
+    public void testMixinOnEnumValues2787() throws Exception
+    {
+        ObjectMapper mapper = jsonMapperBuilder()
+                .addMixIn(SomeEnum2787.class, SomeEnumMixin2787.class)
+                .build();
+        SomeEnum2787 result = mapper.readValue(quote("zero"), SomeEnum2787.class);
+        assertEquals(SomeEnum2787.none, result);
+    }
+}