Adding upstream version 2.6.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

config.go

@@ -0,0 +1,111 @@
+package editorconfig
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/mod/semver"
+)
+
+// ErrInvalidVersion represents a standard error with the semantic version.
+var ErrInvalidVersion = errors.New("invalid semantic version")
+
+// Config holds the configuration.
+type Config struct {
+	Path     string
+	Name     string
+	Version  string
+	Parser   Parser
+	Graceful bool
+}
+
+// Load loads definition of a given file.
+func (config *Config) Load(filename string) (*Definition, error) {
+	definition, warning, err := config.LoadGraceful(filename)
+	if warning != nil {
+		err = errors.Join(err, warning)
+	}
+
+	return definition, err
+}
+
+// Load loads definition of a given file with warnings and error.
+func (config *Config) LoadGraceful(filename string) (*Definition, error, error) { //nolint:funlen
+	// idiomatic go allows empty struct
+	if config.Parser == nil {
+		config.Parser = new(SimpleParser)
+	}
+
+	absFilename, err := filepath.Abs(filename)
+	if err != nil {
+		return nil, nil, fmt.Errorf("cannot get absolute path for %q: %w", filename, err)
+	}
+
+	ecFile := config.Name
+	if ecFile == "" {
+		ecFile = ConfigNameDefault
+	}
+
+	definition := &Definition{}
+	definition.Raw = make(map[string]string)
+
+	if config.Version != "" {
+		version := config.Version
+		if !strings.HasPrefix(version, "v") {
+			version = "v" + version
+		}
+
+		if ok := semver.IsValid(version); !ok {
+			return nil, nil, fmt.Errorf("version %s error: %w", config.Version, ErrInvalidVersion)
+		}
+
+		definition.version = version
+	}
+
+	var warning error
+
+	dir := absFilename
+	for dir != filepath.Dir(dir) {
+		dir = filepath.Dir(dir)
+
+		ec, warn, err := config.Parser.ParseIniGraceful(filepath.Join(dir, ecFile))
+		if warn != nil {
+			warning = errors.Join(warning, warn)
+		}
+
+		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				continue
+			}
+
+			return nil, nil, fmt.Errorf("cannot parse the ini file %q: %w", ecFile, err)
+		}
+
+		// give it the current config.
+		ec.config = config
+
+		relativeFilename := absFilename
+		if len(dir) < len(relativeFilename) {
+			relativeFilename = relativeFilename[len(dir):]
+		}
+
+		// turn any Windows-y filename into the standard forward slash ones.
+		relativeFilename = filepath.ToSlash(relativeFilename)
+
+		def, err := ec.GetDefinitionForFilename(relativeFilename)
+		if err != nil {
+			return nil, nil, fmt.Errorf("cannot get definition for %q: %w", relativeFilename, err)
+		}
+
+		definition.merge(def)
+
+		if ec.Root {
+			break
+		}
+	}
+
+	return definition, warning, nil
+}