buffer: Store the encoding inside the buffer

Author: JoeKar

internal/buffer/buffer.go

@@ -25,6 +25,7 @@ import (
 	"github.com/zyedidia/micro/v2/internal/screen"
 	"github.com/zyedidia/micro/v2/internal/util"
 	"github.com/zyedidia/micro/v2/pkg/highlight"
+	"golang.org/x/text/encoding"
 	"golang.org/x/text/encoding/htmlindex"
 	"golang.org/x/text/encoding/unicode"
 	"golang.org/x/text/transform"
@@ -87,6 +88,8 @@ type SharedBuffer struct {
 	// LocalSettings customized by the user for this buffer only
 	LocalSettings map[string]bool
 
+	encoding encoding.Encoding
+
 	Suggestions   []string
 	Completions   []string
 	CurSuggestion int
@@ -337,9 +340,9 @@ func NewBuffer(r io.Reader, size int64, path string, startcursor Loc, btype BufT
 		}
 		config.UpdatePathGlobLocals(b.Settings, absPath)
 
-		enc, err := htmlindex.Get(b.Settings["encoding"].(string))
+		b.encoding, err = htmlindex.Get(b.Settings["encoding"].(string))
 		if err != nil {
-			enc = unicode.UTF8
+			b.encoding = unicode.UTF8
 			b.Settings["encoding"] = "utf-8"
 		}
 
@@ -350,7 +353,7 @@ func NewBuffer(r io.Reader, size int64, path string, startcursor Loc, btype BufT
 			return NewBufferFromString("", "", btype)
 		}
 		if !hasBackup {
-			reader := bufio.NewReader(transform.NewReader(r, enc.NewDecoder()))
+			reader := bufio.NewReader(transform.NewReader(r, b.encoding.NewDecoder()))
 
 			var ff FileFormat = FFAuto
 

internal/buffer/save.go

@@ -18,7 +18,6 @@ import (
 	"github.com/zyedidia/micro/v2/internal/config"
 	"github.com/zyedidia/micro/v2/internal/screen"
 	"github.com/zyedidia/micro/v2/internal/util"
-	"golang.org/x/text/encoding/htmlindex"
 	"golang.org/x/text/transform"
 )
 
@@ -118,12 +117,7 @@ func openFile(name string, withSudo bool) (wrappedFile, error) {
 }
 
 func (wf wrappedFile) Write(b *Buffer) (int, error) {
-	enc, err := htmlindex.Get(b.Settings["encoding"].(string))
-	if err != nil {
-		return 0, err
-	}
-
-	file := bufio.NewWriter(transform.NewWriter(wf.writeCloser, enc.NewEncoder()))
+	file := bufio.NewWriter(transform.NewWriter(wf.writeCloser, b.encoding.NewEncoder()))
 
 	b.Lock()
 	defer b.Unlock()
@@ -142,7 +136,7 @@ func (wf wrappedFile) Write(b *Buffer) (int, error) {
 
 	if !wf.withSudo {
 		f := wf.writeCloser.(*os.File)
-		err = f.Truncate(0)
+		err := f.Truncate(0)
 		if err != nil {
 			return 0, err
 		}

internal/buffer/settings.go

@@ -7,6 +7,8 @@ import (
 	"github.com/zyedidia/micro/v2/internal/config"
 	ulua "github.com/zyedidia/micro/v2/internal/lua"
 	"github.com/zyedidia/micro/v2/internal/screen"
+	"golang.org/x/text/encoding/htmlindex"
+	"golang.org/x/text/encoding/unicode"
 	luar "layeh.com/gopher-luar"
 )
 
@@ -97,6 +99,12 @@ func (b *Buffer) DoSetOptionNative(option string, nativeValue interface{}) {
 			b.UpdateRules()
 		}
 	} else if option == "encoding" {
+		enc, err := htmlindex.Get(b.Settings["encoding"].(string))
+		if err != nil {
+			enc = unicode.UTF8
+			b.Settings["encoding"] = "utf-8"
+		}
+		b.encoding = enc
 		b.isModified = true
 	} else if option == "readonly" && b.Type.Kind == BTDefault.Kind {
 		b.Type.Readonly = nativeValue.(bool)