Further cleanup for #1253 wrt 2.8

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/util/TokenBuffer.java

@@ -650,6 +650,7 @@ public final void writeStartObject() throws IOException
     @Override // since 2.8
     public void writeStartObject(Object forValue) throws IOException
     {
+        _writeContext.writeValue();
         _append(JsonToken.START_OBJECT);
         JsonWriteContext ctxt = _writeContext.createChildObjectContext();
         _writeContext = ctxt;

src/test/java/com/fasterxml/jackson/databind/util/TestTokenBuffer.java

@@ -359,6 +359,29 @@ private void _verifyOutputContext(JsonStreamContext ctxt1, JsonStreamContext ctx
         _verifyOutputContext(ctxt1.getParent(), ctxt2.getParent());
     }
 
+    // [databind#1253]
+    public void testParentSiblingContext() throws IOException
+    {
+        TokenBuffer buf = new TokenBuffer(null, false); // no ObjectCodec
+
+        // {"a":{},"b":{"c":"cval"}}
+        
+        buf.writeStartObject();
+        buf.writeFieldName("a");
+        buf.writeStartObject();
+        buf.writeEndObject();
+
+        buf.writeFieldName("b");
+        buf.writeStartObject();
+        buf.writeFieldName("c");
+        //This assertion fails (because of 'a')
+        assertEquals("b", buf.getOutputContext().getParent().getCurrentName());
+        buf.writeString("cval");
+        buf.writeEndObject();
+        buf.writeEndObject();
+        buf.close();
+    }
+
     /*
     /**********************************************************
     /* Tests to verify interaction of TokenBuffer and JsonParserSequence