Fix #1842

Author: cowtowncoder

release-notes/VERSION

@@ -13,6 +13,8 @@ Project: jackson-databind
  (reported byb henryptung@github)
 #1807: Jackson-databind caches plain map deserializer and use it even map has `@JsonDeserializer`
  (reported by lexas2509@github)
+#1842: `null` String for `Exception`s deserialized as String "null" instead of `null`
+ (reported by ZeleniJure@github)
 #1843: Include name of unsettable property in exception from `SetterlessProperty.set()`
  (suggested by andreh7@github)
 

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

@@ -437,7 +437,7 @@ public JsonDeserializer<Object> buildThrowableDeserializer(DeserializationContex
         builder.addIgnorable("suppressed");
         /* As well as "message": it will be passed via constructor,
          * as there's no 'setMessage()' method
-        */
+         */
         builder.addIgnorable("message");
 
         // update builder now that all information is in?

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

@@ -107,7 +107,7 @@ public Object deserializeFromObject(JsonParser p, DeserializationContext ctxt) t
             // Maybe it's "message"?
             if (PROP_NAME_MESSAGE.equals(propName)) {
                 if (hasStringCreator) {
-                    throwable = _valueInstantiator.createFromString(ctxt, p.getText());
+                    throwable = _valueInstantiator.createFromString(ctxt, p.getValueAsString());
                     // any pending values?
                     if (pending != null) {
                         for (int i = 0, len = pendingIx; i < len; i += 2) {

src/test/java/com/fasterxml/jackson/databind/exc/ExceptionDeserializationTest.java

@@ -170,4 +170,15 @@ public void testLineNumberAsString() throws IOException
         ), IOException.class);
         assertNotNull(exc);
     }
+
+    // [databind#1842]:
+    public void testNullAsMessage() throws IOException
+    {
+        Exception exc = MAPPER.readValue(aposToQuotes(
+                "{'message':null, 'localizedMessage':null }"
+        ), IOException.class);
+        assertNotNull(exc);
+        assertNull(exc.getMessage());
+        assertNull(exc.getLocalizedMessage());
+    }
 }