1 files changed, 76 insertions, 15 deletions

diff --git a/libgo/go/database/sql/convert.go b/libgo/go/database/sql/convert.go
index 99aed2398e2..ea2f377810e 100644
--- a/libgo/go/database/sql/convert.go
+++ b/libgo/go/database/sql/convert.go
@@ -13,16 +13,36 @@ import (
 	"reflect"
 	"strconv"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var errNilPtr = errors.New("destination pointer is nil") // embedded in descriptive error
 
+func describeNamedValue(nv *driver.NamedValue) string {
+	if len(nv.Name) == 0 {
+		return fmt.Sprintf("$%d", nv.Ordinal)
+	}
+	return fmt.Sprintf("with name %q", nv.Name)
+}
+
+func validateNamedValueName(name string) error {
+	if len(name) == 0 {
+		return nil
+	}
+	r, _ := utf8.DecodeRuneInString(name)
+	if unicode.IsLetter(r) {
+		return nil
+	}
+	return fmt.Errorf("name %q does not begin with a letter", name)
+}
+
 // driverArgs converts arguments from callers of Stmt.Exec and
 // Stmt.Query into driver Values.
 //
 // The statement ds may be nil, if no statement is available.
-func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
-	dargs := make([]driver.Value, len(args))
+func driverArgs(ds *driverStmt, args []interface{}) ([]driver.NamedValue, error) {
+	nvargs := make([]driver.NamedValue, len(args))
 	var si driver.Stmt
 	if ds != nil {
 		si = ds.si
@@ -33,26 +53,45 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
 	if !ok {
 		for n, arg := range args {
 			var err error
-			dargs[n], err = driver.DefaultParameterConverter.ConvertValue(arg)
+			nv := &nvargs[n]
+			nv.Ordinal = n + 1
+			if np, ok := arg.(NamedArg); ok {
+				if err := validateNamedValueName(np.Name); err != nil {
+					return nil, err
+				}
+				arg = np.Value
+				nvargs[n].Name = np.Name
+			}
+			nv.Value, err = driver.DefaultParameterConverter.ConvertValue(arg)
+
 			if err != nil {
-				return nil, fmt.Errorf("sql: converting Exec argument #%d's type: %v", n, err)
+				return nil, fmt.Errorf("sql: converting Exec argument %s type: %v", describeNamedValue(nv), err)
 			}
 		}
-		return dargs, nil
+		return nvargs, nil
 	}
 
 	// Let the Stmt convert its own arguments.
 	for n, arg := range args {
+		nv := &nvargs[n]
+		nv.Ordinal = n + 1
+		if np, ok := arg.(NamedArg); ok {
+			if err := validateNamedValueName(np.Name); err != nil {
+				return nil, err
+			}
+			arg = np.Value
+			nv.Name = np.Name
+		}
 		// First, see if the value itself knows how to convert
 		// itself to a driver type. For example, a NullString
 		// struct changing into a string or nil.
-		if svi, ok := arg.(driver.Valuer); ok {
-			sv, err := svi.Value()
+		if vr, ok := arg.(driver.Valuer); ok {
+			sv, err := callValuerValue(vr)
 			if err != nil {
-				return nil, fmt.Errorf("sql: argument index %d from Value: %v", n, err)
+				return nil, fmt.Errorf("sql: argument %s from Value: %v", describeNamedValue(nv), err)
 			}
 			if !driver.IsValue(sv) {
-				return nil, fmt.Errorf("sql: argument index %d: non-subset type %T returned from Value", n, sv)
+				return nil, fmt.Errorf("sql: argument %s: non-subset type %T returned from Value", describeNamedValue(nv), sv)
 			}
 			arg = sv
 		}
@@ -66,18 +105,18 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
 		// same error.
 		var err error
 		ds.Lock()
-		dargs[n], err = cc.ColumnConverter(n).ConvertValue(arg)
+		nv.Value, err = cc.ColumnConverter(n).ConvertValue(arg)
 		ds.Unlock()
 		if err != nil {
-			return nil, fmt.Errorf("sql: converting argument #%d's type: %v", n, err)
+			return nil, fmt.Errorf("sql: converting argument %s type: %v", describeNamedValue(nv), err)
 		}
-		if !driver.IsValue(dargs[n]) {
-			return nil, fmt.Errorf("sql: driver ColumnConverter error converted %T to unsupported type %T",
-				arg, dargs[n])
+		if !driver.IsValue(nv.Value) {
+			return nil, fmt.Errorf("sql: for argument %s, driver ColumnConverter error converted %T to unsupported type %T",
+				describeNamedValue(nv), arg, nv.Value)
 		}
 	}
 
-	return dargs, nil
+	return nvargs, nil
 }
 
 // convertAssign copies to dest the value in src, converting it if possible.
@@ -330,3 +369,25 @@ func asBytes(buf []byte, rv reflect.Value) (b []byte, ok bool) {
 	}
 	return
 }
+
+var valuerReflectType = reflect.TypeOf((*driver.Valuer)(nil)).Elem()
+
+// callValuerValue returns vr.Value(), with one exception:
+// If vr.Value is an auto-generated method on a pointer type and the
+// pointer is nil, it would panic at runtime in the panicwrap
+// method. Treat it like nil instead.
+// Issue 8415.
+//
+// This is so people can implement driver.Value on value types and
+// still use nil pointers to those types to mean nil/NULL, just like
+// string/*string.
+//
+// This function is mirrored in the database/sql/driver package.
+func callValuerValue(vr driver.Valuer) (v driver.Value, err error) {
+	if rv := reflect.ValueOf(vr); rv.Kind() == reflect.Ptr &&
+		rv.IsNil() &&
+		rv.Type().Elem().Implements(valuerReflectType) {
+		return nil, nil
+	}
+	return vr.Value()
+}