mysql: Fix GetInt() with negative NEWDECIMAL result

mysql/resultset.go

@@ -185,12 +185,45 @@ func (r *Resultset) GetUintByName(row int, name string) (uint64, error) {
 }
 
 func (r *Resultset) GetInt(row, column int) (int64, error) {
-	v, err := r.GetUint(row, column)
+	d, err := r.GetValue(row, column)
 	if err != nil {
 		return 0, err
 	}
 
-	return int64(v), nil
+	switch v := d.(type) {
+	case int:
+		return int64(v), nil
+	case int8:
+		return int64(v), nil
+	case int16:
+		return int64(v), nil
+	case int32:
+		return int64(v), nil
+	case int64:
+		return v, nil
+	case uint:
+		return int64(v), nil
+	case uint8:
+		return int64(v), nil
+	case uint16:
+		return int64(v), nil
+	case uint32:
+		return int64(v), nil
+	case uint64:
+		return int64(v), nil
+	case float32:
+		return int64(v), nil
+	case float64:
+		return int64(v), nil
+	case string:
+		return strconv.ParseInt(v, 10, 64)
+	case []byte:
+		return strconv.ParseInt(string(v), 10, 64)
+	case nil:
+		return 0, nil
+	default:
+		return 0, errors.Errorf("data type is %T", v)
+	}
 }
 
 func (r *Resultset) GetIntByName(row int, name string) (int64, error) {

mysql/resultset_test.go

@@ -1,10 +1,24 @@
 package mysql
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
 
 func TestColumnNumber(t *testing.T) {
 	r := NewResultReserveResultset(0)
 	// Make sure ColumnNumber doesn't panic when constructing a Result with 0
 	// columns. https://github.com/go-mysql-org/go-mysql/issues/964
 	r.ColumnNumber()
 }
+
+// TestGetInt tests GetInt with a negative value
+func TestGetIntNeg(t *testing.T) {
+	r := NewResultset(1)
+	fv := NewFieldValue(FieldValueTypeString, 0, []uint8("-193"))
+	r.Values = [][]FieldValue{{fv}}
+	v, err := r.GetInt(0, 0)
+	require.NoError(t, err)
+	require.Equal(t, int64(-193), v)
+}