Fixed metadata pointer bug

Author: oschwald

src/main/java/com/maxmind/maxminddb/MaxMindDbReader.java

@@ -66,7 +66,7 @@ public MaxMindDbReader(File database, FileMode fileMode) throws IOException {
         this.threadBuffer = new ThreadBuffer(database, fileMode);
         int start = this.findMetadataStart(database.getName());
 
-        Decoder metadataDecoder = new Decoder(this.threadBuffer, 0);
+        Decoder metadataDecoder = new Decoder(this.threadBuffer, start);
         this.metadata = new Metadata(metadataDecoder.decode(start).getNode());
         this.decoder = new Decoder(this.threadBuffer,
                 this.metadata.searchTreeSize + DATA_SECTION_SEPARATOR_SIZE);

src/test/java/com/maxmind/maxminddb/ReaderTest.java

@@ -43,6 +43,18 @@ public void test() throws InvalidDatabaseException, IOException,
         }
     }
 
+    @Test
+    public void testNoIpV4SearchTree() throws IOException, URISyntaxException {
+        URI file = ReaderTest.class.getResource(
+                "/maxmind-db/test-data/MaxMind-DB-no-ipv4-search-tree.mmdb")
+                .toURI();
+
+        MaxMindDbReader reader = new MaxMindDbReader(new File(file));
+
+        assertEquals("::/64", reader.get(InetAddress.getByName("::1:1.1.1.1"))
+                .textValue());
+    }
+
     private void testMetadata(MaxMindDbReader reader, int ipVersion,
             long recordSize) {