Fixed deserialization of JSON objects that contain empty keys (#170)

Author: shyiko

src/main/java/com/github/shyiko/mysql/binlog/event/deserialization/json/JsonBinary.java

@@ -872,7 +872,7 @@ protected long readBigEndianLong(int numBytes) throws IOException {
 
     protected int readUnsignedIndex(int maxValue, boolean isSmall, String desc) throws IOException {
         long result = isSmall ? readUInt16() : readUInt32();
-        if (result >= maxValue) {
+        if (result > maxValue) {
             throw new IOException("The " + desc + " the JSON document is " + result +
                     " and is too big for the binary form of the document (" + maxValue + ")");
         }

src/test/java/com/github/shyiko/mysql/binlog/event/deserialization/json/JsonBinaryValueIntegrationTest.java

@@ -205,6 +205,11 @@ public void testJsonObjectNested() throws Exception {
         assertJSONMatchOriginal("{\"a\":{\"b\":{\"c\":\"d\",\"e\":[\"f\",\"g\"]}}}");
     }
 
+    @Test
+    public void testJsonWithEmptyKey() throws Exception {
+        assertJSONMatchOriginal("{\"bitrate\":{\"\":0}}");
+    }
+
     @Test
     public void testJsonArray() throws Exception {
         assertJSONMatchOriginal(