Improved initial handshake error reporting (by including actual error message from MySQL)

Author: shyiko

src/main/java/com/github/shyiko/mysql/binlog/BinaryLogClient.java

@@ -331,7 +331,14 @@ public void connect() throws IOException {
                 throw new IOException("Failed to connect to MySQL on " + hostname + ":" + port +
                     ". Please make sure it's running.", e);
             }
-            GreetingPacket greetingPacket = new GreetingPacket(channel.read());
+            byte[] initialHandshakePacket = channel.read();
+            if (initialHandshakePacket[0] == (byte) 0xFF /* error */) {
+                byte[] bytes = Arrays.copyOfRange(initialHandshakePacket, 1, initialHandshakePacket.length);
+                ErrorPacket errorPacket = new ErrorPacket(bytes);
+                throw new ServerException(errorPacket.getErrorMessage(), errorPacket.getErrorCode(),
+                        errorPacket.getSqlState());
+            }
+            GreetingPacket greetingPacket = new GreetingPacket(initialHandshakePacket);
             authenticate(greetingPacket.getScramble(), greetingPacket.getServerCollation());
             if (binlogFilename == null) {
                 fetchBinlogFilenameAndPosition();

src/main/java/com/github/shyiko/mysql/binlog/network/protocol/ErrorPacket.java

@@ -31,8 +31,10 @@ public class ErrorPacket implements Packet {
     public ErrorPacket(byte[] bytes) throws IOException {
         ByteArrayInputStream buffer = new ByteArrayInputStream(bytes);
         this.errorCode = buffer.readInteger(2);
-        buffer.skip(1); // 1 byte for slash
-        this.sqlState = buffer.readString(5);
+        if (buffer.peek() == '#') {
+            buffer.skip(1); // marker of the SQL State
+            this.sqlState = buffer.readString(5);
+        }
         this.errorMessage = buffer.readString(buffer.available());
     }