reset and recommit to fix muddled merge

Author: arnehormann

connection.go

@@ -111,7 +111,9 @@ func (mc *mysqlConn) Begin() (driver.Tx, error) {
 	if err == nil {
 		return &mysqlTx{mc}, err
 	}
-
+	if err == errNoWrite {
+		return nil, driver.ErrBadConn
+	}
 	return nil, err
 }
 
@@ -141,6 +143,9 @@ func (mc *mysqlConn) Prepare(query string) (driver.Stmt, error) {
 	// Send command
 	err := mc.writeCommandPacketStr(comStmtPrepare, query)
 	if err != nil {
+		if err == errNoWrite {
+			return nil, driver.ErrBadConn
+		}
 		return nil, err
 	}
 
@@ -324,13 +329,15 @@ func (mc *mysqlConn) Exec(query string, args []driver.Value) (driver.Result, err
 	}
 	mc.affectedRows = 0
 	mc.insertId = 0
-
 	err := mc.exec(query)
 	if err == nil {
 		return &mysqlResult{
 			affectedRows: int64(mc.affectedRows),
 			insertId:     int64(mc.insertId),
-		}, err
+		}, nil
+	}
+	if err == errNoWrite {
+		return nil, driver.ErrBadConn
 	}
 	return nil, err
 }
@@ -380,17 +387,23 @@ func (mc *mysqlConn) Query(query string, args []driver.Value) (driver.Rows, erro
 		var resLen int
 		resLen, err = mc.readResultSetHeaderPacket()
 		if err == nil {
-			rows := new(textRows)
-			rows.mc = mc
-
 			if resLen == 0 {
 				// no columns, no more data
 				return emptyRows{}, nil
 			}
-			// Columns
-			rows.columns, err = mc.readColumns(resLen)
-			return rows, err
+			cols, err := mc.readColumns(resLen)
+			if err != nil {
+				return nil, err
+			}
+			return &textRows{mysqlRows{
+				mc:      mc,
+				columns: cols,
+			}}, nil
 		}
+		return nil, err
+	}
+	if err == errNoWrite {
+		return nil, driver.ErrBadConn
 	}
 	return nil, err
 }
@@ -400,6 +413,9 @@ func (mc *mysqlConn) Query(query string, args []driver.Value) (driver.Rows, erro
 func (mc *mysqlConn) getSystemVar(name string) ([]byte, error) {
 	// Send command
 	if err := mc.writeCommandPacketStr(comQuery, "SELECT @@"+name); err != nil {
+		if err == errNoWrite {
+			return nil, driver.ErrBadConn
+		}
 		return nil, err
 	}
 

driver.go

@@ -118,6 +118,9 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 	maxap, err := mc.getSystemVar("max_allowed_packet")
 	if err != nil {
 		mc.Close()
+		if err == driver.ErrBadConn {
+			err = ErrInvalidConn
+		}
 		return nil, err
 	}
 	mc.maxPacketAllowed = stringToInt(maxap) - 1

errors.go

@@ -28,6 +28,7 @@ var (
 	ErrPktSyncMul  = errors.New("Commands out of sync. Did you run multiple statements at once?")
 	ErrPktTooLarge = errors.New("Packet for query is too large. You can change this value on the server by adjusting the 'max_allowed_packet' variable.")
 	ErrBusyBuffer  = errors.New("Busy buffer")
+	errNoWrite     = errors.New("No data written")
 )
 
 var errLog Logger = log.New(os.Stderr, "[MySQL] ", log.Ldate|log.Ltime|log.Lshortfile)

packets.go

@@ -31,7 +31,7 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 		if err != nil {
 			errLog.Print(err)
 			mc.Close()
-			return nil, driver.ErrBadConn
+			return nil, ErrInvalidConn
 		}
 
 		// Packet Length [24 bit]
@@ -40,7 +40,7 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 		if pktLen < 1 {
 			errLog.Print(ErrMalformPkt)
 			mc.Close()
-			return nil, driver.ErrBadConn
+			return nil, ErrInvalidConn
 		}
 
 		// Check Packet Sync [8 bit]
@@ -58,7 +58,7 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 		if err != nil {
 			errLog.Print(err)
 			mc.Close()
-			return nil, driver.ErrBadConn
+			return nil, ErrInvalidConn
 		}
 
 		isLastPacket := (pktLen < maxPacketSize)
@@ -114,10 +114,14 @@ func (mc *mysqlConn) writePacket(data []byte) error {
 		// Handle error
 		if err == nil { // n != len(data)
 			errLog.Print(ErrMalformPkt)
-		} else {
-			errLog.Print(err)
+			return ErrMalformPkt
 		}
-		return driver.ErrBadConn
+		errLog.Print(err)
+		if n == 0 && pktLen == len(data)-4 {
+			// first loop iteration, nothing was written
+			return errNoWrite
+		}
+		return ErrInvalidConn
 	}
 }
 
@@ -241,7 +245,7 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// ClientFlags [32 bit]
@@ -312,7 +316,7 @@ func (mc *mysqlConn) writeOldAuthPacket(cipher []byte) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// Add the scrambled password [null terminated string]
@@ -334,7 +338,7 @@ func (mc *mysqlConn) writeCommandPacket(command byte) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// Add command byte
@@ -353,7 +357,7 @@ func (mc *mysqlConn) writeCommandPacketStr(command byte, arg string) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// Add command byte
@@ -374,7 +378,7 @@ func (mc *mysqlConn) writeCommandPacketUint32(command byte, arg uint32) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// Add command byte
@@ -741,6 +745,10 @@ func (stmt *mysqlStmt) writeCommandLongData(paramID int, arg []byte) error {
 			data = data[pktLen-dataOffset:]
 			continue
 		}
+		if err == errNoWrite && argLen != len(arg) {
+			// must not relay errNoWrite after first loop iteration
+			return ErrInvalidConn
+		}
 		return err
 
 	}
@@ -777,7 +785,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 	if data == nil {
 		// can not take the buffer. Something must be wrong with the connection
 		errLog.Print(ErrBusyBuffer)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	// command [1 byte]

statement.go

@@ -22,10 +22,13 @@ type mysqlStmt struct {
 func (stmt *mysqlStmt) Close() error {
 	if stmt.mc == nil || stmt.mc.netConn == nil {
 		errLog.Print(ErrInvalidConn)
-		return driver.ErrBadConn
+		return ErrInvalidConn
 	}
 
 	err := stmt.mc.writeCommandPacketUint32(comStmtClose, stmt.id)
+	if err == errNoWrite {
+		err = ErrInvalidConn
+	}
 	stmt.mc = nil
 	return err
 }
@@ -42,6 +45,9 @@ func (stmt *mysqlStmt) Exec(args []driver.Value) (driver.Result, error) {
 	// Send command
 	err := stmt.writeExecutePacket(args)
 	if err != nil {
+		if err == errNoWrite {
+			return nil, driver.ErrBadConn
+		}
 		return nil, err
 	}
 
@@ -82,6 +88,9 @@ func (stmt *mysqlStmt) Query(args []driver.Value) (driver.Rows, error) {
 	// Send command
 	err := stmt.writeExecutePacket(args)
 	if err != nil {
+		if err == errNoWrite {
+			return nil, driver.ErrBadConn
+		}
 		return nil, err
 	}