Fix review comments for PR microsoft#628

- Fix nil encoder panic in errorCommand when using UTF-8 codepage
- Improve error handling with proper file close on encoding error
- Remove dead code (unused 'err' variable) in format.go
- Add missing -R flag test in TestValidCommandLineToArgsConversion

Author: dlevy-msft-sql

cmd/sqlcmd/sqlcmd_test.go

@@ -139,6 +139,13 @@ func TestValidCommandLineToArgsConversion(t *testing.T) {
 		{[]string{"--list-codepages"}, func(args SQLCmdArguments) bool {
 			return args.ListCodePages
 		}},
+		// Regional settings flag test
+		{[]string{"-R"}, func(args SQLCmdArguments) bool {
+			return args.UseRegionalSettings
+		}},
+		{[]string{"--client-regional-setting"}, func(args SQLCmdArguments) bool {
+			return args.UseRegionalSettings
+		}},
 	}
 
 	for _, test := range commands {

pkg/sqlcmd/commands.go

@@ -370,11 +370,18 @@ func errorCommand(s *Sqlcmd, args []string, line uint) error {
 		if s.CodePage != nil && s.CodePage.OutputCodePage != 0 {
 			enc, err := GetEncoding(s.CodePage.OutputCodePage)
 			if err != nil {
-				o.Close()
+				if cerr := o.Close(); cerr != nil {
+					return fmt.Errorf("%w (and closing error file %s failed: %v)", err, filePath, cerr)
+				}
 				return err
 			}
-			encoder := transform.NewWriter(o, enc.NewEncoder())
-			s.SetError(encoder)
+			if enc == nil {
+				// No transformation required (e.g., UTF-8), write directly
+				s.SetError(o)
+			} else {
+				encoder := transform.NewWriter(o, enc.NewEncoder())
+				s.SetError(encoder)
+			}
 		} else {
 			s.SetError(o)
 		}

pkg/sqlcmd/format.go

@@ -567,7 +567,6 @@ func (f *sqlCmdFormatterType) scanRow(rows *sql.Rows) ([]string, error) {
 					row[n] = "0"
 				}
 			default:
-				var err error
 				val := fmt.Sprintf("%v", x)
 				// Apply regional formatting for numeric types
 				if f.regional.IsEnabled() {
@@ -582,9 +581,6 @@ func (f *sqlCmdFormatterType) scanRow(rows *sql.Rows) ([]string, error) {
 				} else {
 					row[n] = val
 				}
-				if err != nil {
-					return nil, err
-				}
 			}
 		}
 	}