Improve control char rendering and escape button styling (#37094)

Follow-up to #37078.

- Use Unicode Control Pictures](U+2400-U+2421) to render C0 control characters
- Make it work in diff view too
- Replace escape warning emoji with SVG
- Align escape warning button with code lines

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/charset/ambiguous.go

@@ -1,4 +1,3 @@
-// This file is generated by modules/charset/ambiguous/generate.go DO NOT EDIT
 // Copyright 2022 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
@@ -14,11 +13,12 @@ import (
 
 // AmbiguousTablesForLocale provides the table of ambiguous characters for this locale.
 func AmbiguousTablesForLocale(locale translation.Locale) []*AmbiguousTable {
+	ambiguousTableMap := globalVars().ambiguousTableMap
 	key := locale.Language()
 	var table *AmbiguousTable
 	var ok bool
 	for len(key) > 0 {
-		if table, ok = AmbiguousCharacters[key]; ok {
+		if table, ok = ambiguousTableMap[key]; ok {
 			break
 		}
 		idx := strings.LastIndexAny(key, "-_")
@@ -29,18 +29,18 @@ func AmbiguousTablesForLocale(locale translation.Locale) []*AmbiguousTable {
 		}
 	}
 	if table == nil && (locale.Language() == "zh-CN" || locale.Language() == "zh_CN") {
-		table = AmbiguousCharacters["zh-hans"]
+		table = ambiguousTableMap["zh-hans"]
 	}
 	if table == nil && strings.HasPrefix(locale.Language(), "zh") {
-		table = AmbiguousCharacters["zh-hant"]
+		table = ambiguousTableMap["zh-hant"]
 	}
 	if table == nil {
-		table = AmbiguousCharacters["_default"]
+		table = ambiguousTableMap["_default"]
 	}
 
 	return []*AmbiguousTable{
 		table,
-		AmbiguousCharacters["_common"],
+		ambiguousTableMap["_common"],
 	}
 }
 
@@ -52,7 +52,7 @@ func isAmbiguous(r rune, confusableTo *rune, tables ...*AmbiguousTable) bool {
 		i := sort.Search(len(table.Confusable), func(i int) bool {
 			return table.Confusable[i] >= r
 		})
-		(*confusableTo) = table.With[i]
+		*confusableTo = table.With[i]
 		return true
 	}
 	return false

modules/charset/ambiguous/generate.go

@@ -1,188 +0,0 @@
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package main
-
-import (
-	"bytes"
-	"flag"
-	"fmt"
-	"go/format"
-	"os"
-	"sort"
-	"text/template"
-	"unicode"
-
-	"code.gitea.io/gitea/modules/json"
-
-	"golang.org/x/text/unicode/rangetable"
-)
-
-// ambiguous.json provides a one to one mapping of ambiguous characters to other characters
-// See https://github.com/hediet/vscode-unicode-data/blob/main/out/ambiguous.json
-
-type AmbiguousTable struct {
-	Confusable []rune
-	With       []rune
-	Locale     string
-	RangeTable *unicode.RangeTable
-}
-
-type RunePair struct {
-	Confusable rune
-	With       rune
-}
-
-var verbose bool
-
-func main() {
-	flag.Usage = func() {
-		fmt.Fprintf(os.Stderr, `%s: Generate AmbiguousCharacter
-
-Usage: %[1]s [-v] [-o output.go] ambiguous.json
-`, os.Args[0])
-		flag.PrintDefaults()
-	}
-
-	output := ""
-	flag.BoolVar(&verbose, "v", false, "verbose output")
-	flag.StringVar(&output, "o", "ambiguous_gen.go", "file to output to")
-	flag.Parse()
-	input := flag.Arg(0)
-	if input == "" {
-		input = "ambiguous.json"
-	}
-
-	bs, err := os.ReadFile(input)
-	if err != nil {
-		fatalf("Unable to read: %s Err: %v", input, err)
-	}
-
-	var unwrapped string
-	if err := json.Unmarshal(bs, &unwrapped); err != nil {
-		fatalf("Unable to unwrap content in: %s Err: %v", input, err)
-	}
-
-	fromJSON := map[string][]uint32{}
-	if err := json.Unmarshal([]byte(unwrapped), &fromJSON); err != nil {
-		fatalf("Unable to unmarshal content in: %s Err: %v", input, err)
-	}
-
-	tables := make([]*AmbiguousTable, 0, len(fromJSON))
-	for locale, chars := range fromJSON {
-		table := &AmbiguousTable{Locale: locale}
-		table.Confusable = make([]rune, 0, len(chars)/2)
-		table.With = make([]rune, 0, len(chars)/2)
-		pairs := make([]RunePair, len(chars)/2)
-		for i := 0; i < len(chars); i += 2 {
-			pairs[i/2].Confusable, pairs[i/2].With = rune(chars[i]), rune(chars[i+1])
-		}
-		sort.Slice(pairs, func(i, j int) bool {
-			return pairs[i].Confusable < pairs[j].Confusable
-		})
-		for _, pair := range pairs {
-			table.Confusable = append(table.Confusable, pair.Confusable)
-			table.With = append(table.With, pair.With)
-		}
-		table.RangeTable = rangetable.New(table.Confusable...)
-		tables = append(tables, table)
-	}
-	sort.Slice(tables, func(i, j int) bool {
-		return tables[i].Locale < tables[j].Locale
-	})
-	data := map[string]any{
-		"Tables": tables,
-	}
-
-	if err := runTemplate(generatorTemplate, output, &data); err != nil {
-		fatalf("Unable to run template: %v", err)
-	}
-}
-
-func runTemplate(t *template.Template, filename string, data any) error {
-	buf := bytes.NewBuffer(nil)
-	if err := t.Execute(buf, data); err != nil {
-		return fmt.Errorf("unable to execute template: %w", err)
-	}
-	bs, err := format.Source(buf.Bytes())
-	if err != nil {
-		verbosef("Bad source:\n%s", buf.String())
-		return fmt.Errorf("unable to format source: %w", err)
-	}
-
-	old, err := os.ReadFile(filename)
-	if err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("failed to read old file %s because %w", filename, err)
-	} else if err == nil {
-		if bytes.Equal(bs, old) {
-			// files are the same don't rewrite it.
-			return nil
-		}
-	}
-
-	file, err := os.Create(filename)
-	if err != nil {
-		return fmt.Errorf("failed to create file %s because %w", filename, err)
-	}
-	defer file.Close()
-	_, err = file.Write(bs)
-	if err != nil {
-		return fmt.Errorf("unable to write generated source: %w", err)
-	}
-	return nil
-}
-
-var generatorTemplate = template.Must(template.New("ambiguousTemplate").Parse(`// This file is generated by modules/charset/ambiguous/generate.go DO NOT EDIT
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-
-package charset
-
-import "unicode"
-
-// This file is generated from https://github.com/hediet/vscode-unicode-data/blob/main/out/ambiguous.json
-
-// AmbiguousTable matches a confusable rune with its partner for the Locale
-type AmbiguousTable struct {
-	Confusable []rune
-	With       []rune
-	Locale     string
-	RangeTable *unicode.RangeTable
-}
-
-// AmbiguousCharacters provides a map by locale name to the confusable characters in that locale
-var AmbiguousCharacters = map[string]*AmbiguousTable{
-	{{range .Tables}}{{printf "%q:" .Locale}} {
-			Confusable: []rune{ {{range .Confusable}}{{.}},{{end}} },
-			With: []rune{ {{range .With}}{{.}},{{end}} },
-			Locale: {{printf "%q" .Locale}},
-			RangeTable: &unicode.RangeTable{
-				R16: []unicode.Range16{
-			{{range .RangeTable.R16 }}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
-			{{end}}	},
-				R32: []unicode.Range32{
-			{{range .RangeTable.R32}}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
-			{{end}}	},
-				LatinOffset: {{.RangeTable.LatinOffset}},
-			},
-		},
-	{{end}}
-}
-
-`))
-
-func logf(format string, args ...any) {
-	fmt.Fprintf(os.Stderr, format+"\n", args...)
-}
-
-func verbosef(format string, args ...any) {
-	if verbose {
-		logf(format, args...)
-	}
-}
-
-func fatalf(format string, args ...any) {
-	logf("fatal: "+format+"\n", args...)
-	os.Exit(1)
-}

modules/charset/ambiguous_gen_test.go

@@ -8,11 +8,13 @@ import (
 	"testing"
 	"unicode"
 
+	"code.gitea.io/gitea/modules/translation"
+
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAmbiguousCharacters(t *testing.T) {
-	for locale, ambiguous := range AmbiguousCharacters {
+	for locale, ambiguous := range globalVars().ambiguousTableMap {
 		assert.Equal(t, locale, ambiguous.Locale)
 		assert.Len(t, ambiguous.With, len(ambiguous.Confusable))
 		assert.True(t, sort.SliceIsSorted(ambiguous.Confusable, func(i, j int) bool {
@@ -28,4 +30,8 @@ func TestAmbiguousCharacters(t *testing.T) {
 			assert.True(t, found, "%c is not in %d", confusable, i)
 		}
 	}
+
+	var confusableTo rune
+	ret := isAmbiguous('𝐾', &confusableTo, AmbiguousTablesForLocale(&translation.MockLocale{})...)
+	assert.True(t, ret)
 }

modules/charset/breakwriter.go

@@ -1,43 +0,0 @@
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package charset
-
-import (
-	"bytes"
-	"io"
-)
-
-// BreakWriter wraps an io.Writer to always write '\n' as '<br>'
-type BreakWriter struct {
-	io.Writer
-}
-
-// Write writes the provided byte slice transparently replacing '\n' with '<br>'
-func (b *BreakWriter) Write(bs []byte) (n int, err error) {
-	pos := 0
-	for pos < len(bs) {
-		idx := bytes.IndexByte(bs[pos:], '\n')
-		if idx < 0 {
-			wn, err := b.Writer.Write(bs[pos:])
-			return n + wn, err
-		}
-
-		if idx > 0 {
-			wn, err := b.Writer.Write(bs[pos : pos+idx])
-			n += wn
-			if err != nil {
-				return n, err
-			}
-		}
-
-		if _, err = b.Writer.Write([]byte("<br>")); err != nil {
-			return n, err
-		}
-		pos += idx + 1
-
-		n++
-	}
-
-	return n, err
-}

modules/charset/breakwriter_test.go

@@ -1,68 +0,0 @@
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package charset
-
-import (
-	"strings"
-	"testing"
-)
-
-func TestBreakWriter_Write(t *testing.T) {
-	tests := []struct {
-		name    string
-		kase    string
-		expect  string
-		wantErr bool
-	}{
-		{
-			name:   "noline",
-			kase:   "abcdefghijklmnopqrstuvwxyz",
-			expect: "abcdefghijklmnopqrstuvwxyz",
-		},
-		{
-			name:   "endline",
-			kase:   "abcdefghijklmnopqrstuvwxyz\n",
-			expect: "abcdefghijklmnopqrstuvwxyz<br>",
-		},
-		{
-			name:   "startline",
-			kase:   "\nabcdefghijklmnopqrstuvwxyz",
-			expect: "<br>abcdefghijklmnopqrstuvwxyz",
-		},
-		{
-			name:   "onlyline",
-			kase:   "\n\n\n",
-			expect: "<br><br><br>",
-		},
-		{
-			name:   "empty",
-			kase:   "",
-			expect: "",
-		},
-		{
-			name:   "midline",
-			kase:   "\nabc\ndefghijkl\nmnopqrstuvwxy\nz",
-			expect: "<br>abc<br>defghijkl<br>mnopqrstuvwxy<br>z",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			buf := &strings.Builder{}
-			b := &BreakWriter{
-				Writer: buf,
-			}
-			n, err := b.Write([]byte(tt.kase))
-			if (err != nil) != tt.wantErr {
-				t.Errorf("BreakWriter.Write() error = %v, wantErr %v", err, tt.wantErr)
-				return
-			}
-			if n != len(tt.kase) {
-				t.Errorf("BreakWriter.Write() = %v, want %v", n, len(tt.kase))
-			}
-			if buf.String() != tt.expect {
-				t.Errorf("BreakWriter.Write() wrote %q, want %v", buf.String(), tt.expect)
-			}
-		})
-	}
-}

modules/charset/charset.go

@@ -6,7 +6,10 @@ package charset
 import (
 	"bytes"
 	"io"
+	"regexp"
 	"strings"
+	"sync"
+	"unicode"
 	"unicode/utf8"
 
 	"code.gitea.io/gitea/modules/setting"
@@ -17,8 +20,19 @@ import (
 	"golang.org/x/text/transform"
 )
 
-// UTF8BOM is the utf-8 byte-order marker
-var UTF8BOM = []byte{'\xef', '\xbb', '\xbf'}
+var globalVars = sync.OnceValue(func() (ret struct {
+	utf8Bom []byte
+
+	defaultWordRegexp   *regexp.Regexp
+	ambiguousTableMap   map[string]*AmbiguousTable
+	invisibleRangeTable *unicode.RangeTable
+},
+) {
+	ret.utf8Bom = []byte{'\xef', '\xbb', '\xbf'}
+	ret.ambiguousTableMap = newAmbiguousTableMap()
+	ret.invisibleRangeTable = newInvisibleRangeTable()
+	return ret
+})
 
 type ConvertOpts struct {
 	KeepBOM           bool
@@ -105,7 +119,7 @@ func maybeRemoveBOM(content []byte, opts ConvertOpts) []byte {
 	if opts.KeepBOM {
 		return content
 	}
-	return bytes.TrimPrefix(content, UTF8BOM)
+	return bytes.TrimPrefix(content, globalVars().utf8Bom)
 }
 
 // DetectEncoding detect the encoding of content

modules/charset/escape.go

@@ -1,10 +1,6 @@
 // Copyright 2022 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
-//go:generate go run invisible/generate.go -v -o ./invisible_gen.go
-
-//go:generate go run ambiguous/generate.go -v -o ./ambiguous_gen.go ambiguous/ambiguous.json
-
 package charset
 
 import (
@@ -12,36 +8,36 @@ import (
 	"io"
 	"strings"
 
-	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/translation"
 )
 
-// RuneNBSP is the codepoint for NBSP
-const RuneNBSP = 0xa0
+type EscapeOptions struct {
+	Allowed map[rune]bool
+}
+
+func AllowRuneNBSP() map[rune]bool {
+	return map[rune]bool{0xa0: true}
+}
+
+func EscapeOptionsForView() EscapeOptions {
+	return EscapeOptions{
+		// it's safe to see NBSP in the view, but maybe not in the diff
+		Allowed: AllowRuneNBSP(),
+	}
+}
 
 // EscapeControlHTML escapes the Unicode control sequences in a provided html document
-func EscapeControlHTML(html template.HTML, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, output template.HTML) {
+func EscapeControlHTML(html template.HTML, locale translation.Locale, opts ...EscapeOptions) (escaped *EscapeStatus, output template.HTML) {
 	if !setting.UI.AmbiguousUnicodeDetection {
 		return &EscapeStatus{}, html
 	}
 	sb := &strings.Builder{}
-	escaped, _ = EscapeControlReader(strings.NewReader(string(html)), sb, locale, allowed...) // err has been handled in EscapeControlReader
+	escaped, _ = EscapeControlReader(strings.NewReader(string(html)), sb, locale, opts...) // err has been handled in EscapeControlReader
 	return escaped, template.HTML(sb.String())
 }
 
 // EscapeControlReader escapes the Unicode control sequences in a provided reader of HTML content and writer in a locale and returns the findings as an EscapeStatus
-func EscapeControlReader(reader io.Reader, writer io.Writer, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, err error) {
-	if !setting.UI.AmbiguousUnicodeDetection {
-		_, err = io.Copy(writer, reader)
-		return &EscapeStatus{}, err
-	}
-	outputStream := &HTMLStreamerWriter{Writer: writer}
-	streamer := NewEscapeStreamer(locale, outputStream, allowed...).(*escapeStreamer)
-
-	if err = StreamHTML(reader, streamer); err != nil {
-		streamer.escaped.HasError = true
-		log.Error("Error whilst escaping: %v", err)
-	}
-	return streamer.escaped, err
+func EscapeControlReader(reader io.Reader, writer io.Writer, locale translation.Locale, opts ...EscapeOptions) (*EscapeStatus, error) {
+	return escapeStream(locale, reader, writer, opts...)
 }

modules/charset/escape_status.go

@@ -3,11 +3,9 @@
 
 package charset
 
-// EscapeStatus represents the findings of the unicode escaper
+// EscapeStatus represents the findings of the Unicode escaper
 type EscapeStatus struct {
-	Escaped      bool
-	HasError     bool
-	HasBadRunes  bool
+	Escaped      bool // it means that some characters were escaped, and they can also be unescaped back
 	HasInvisible bool
 	HasAmbiguous bool
 }
@@ -19,8 +17,6 @@ func (status *EscapeStatus) Or(other *EscapeStatus) *EscapeStatus {
 		st = &EscapeStatus{}
 	}
 	st.Escaped = st.Escaped || other.Escaped
-	st.HasError = st.HasError || other.HasError
-	st.HasBadRunes = st.HasBadRunes || other.HasBadRunes
 	st.HasAmbiguous = st.HasAmbiguous || other.HasAmbiguous
 	st.HasInvisible = st.HasInvisible || other.HasInvisible
 	return st

modules/charset/escape_stream.go

@@ -4,288 +4,415 @@
 package charset
 
 import (
+	"bytes"
 	"fmt"
-	"regexp"
-	"strings"
+	"html"
+	"io"
 	"unicode"
 	"unicode/utf8"
 
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/translation"
-
-	"golang.org/x/net/html"
 )
 
-// VScode defaultWordRegexp
-var defaultWordRegexp = regexp.MustCompile(`(-?\d*\.\d\w*)|([^\` + "`" + `\~\!\@\#\$\%\^\&\*\(\)\-\=\+\[\{\]\}\\\|\;\:\'\"\,\.\<\>\/\?\s\x00-\x1f]+)`)
-
-func NewEscapeStreamer(locale translation.Locale, next HTMLStreamer, allowed ...rune) HTMLStreamer {
-	allowedM := make(map[rune]bool, len(allowed))
-	for _, v := range allowed {
-		allowedM[v] = true
-	}
-	return &escapeStreamer{
-		escaped:                 &EscapeStatus{},
-		PassthroughHTMLStreamer: *NewPassthroughStreamer(next),
-		locale:                  locale,
-		ambiguousTables:         AmbiguousTablesForLocale(locale),
-		allowed:                 allowedM,
-	}
+type htmlChunkReader struct {
+	in       io.Reader
+	readErr  error
+	readBuf  []byte
+	curInTag bool
 }
 
 type escapeStreamer struct {
-	PassthroughHTMLStreamer
+	htmlChunkReader
+
 	escaped         *EscapeStatus
 	locale          translation.Locale
 	ambiguousTables []*AmbiguousTable
 	allowed         map[rune]bool
+
+	out io.Writer
 }
 
-func (e *escapeStreamer) EscapeStatus() *EscapeStatus {
-	return e.escaped
+func escapeStream(locale translation.Locale, in io.Reader, out io.Writer, opts ...EscapeOptions) (*EscapeStatus, error) {
+	es := &escapeStreamer{
+		escaped:         &EscapeStatus{},
+		locale:          locale,
+		ambiguousTables: AmbiguousTablesForLocale(locale),
+		htmlChunkReader: htmlChunkReader{
+			in:      in,
+			readBuf: make([]byte, 0, 32*1024),
+		},
+		out: out,
+	}
+
+	if len(opts) > 0 {
+		es.allowed = opts[0].Allowed
+	}
+
+	readCount := 0
+	lastIsTag := false
+	for {
+		parts, partInTag, err := es.readRunes()
+		readCount++
+		if err == io.EOF {
+			return es.escaped, nil
+		} else if err != nil {
+			return nil, err
+		}
+		for i, part := range parts {
+			if partInTag[i] {
+				lastIsTag = true
+				if _, err := out.Write(part); err != nil {
+					return nil, err
+				}
+			} else {
+				// if last part is tag, then this part is content begin
+				// if the content is the first part of the first read, then it's also content begin
+				isContentBegin := lastIsTag || (readCount == 1 && i == 0)
+				lastIsTag = false
+				if isContentBegin {
+					if part, err = es.trimAndWriteBom(part); err != nil {
+						return nil, err
+					}
+				}
+				if err = es.detectAndWriteRunes(part); err != nil {
+					return nil, err
+				}
+			}
+		}
+	}
 }
 
-// Text tells the next streamer there is a text
-func (e *escapeStreamer) Text(data string) error {
-	sb := &strings.Builder{}
-	var until int
-	var next int
+func (e *escapeStreamer) trimAndWriteBom(part []byte) ([]byte, error) {
+	remaining, ok := bytes.CutPrefix(part, globalVars().utf8Bom)
+	if ok {
+		part = remaining
+		if _, err := e.out.Write(globalVars().utf8Bom); err != nil {
+			return part, err
+		}
+	}
+	return part, nil
+}
+
+const longSentenceDetectionLimit = 20
+
+func (e *escapeStreamer) possibleLongSentence(results []detectResult, pos int) bool {
+	countBasic := 0
+	countNonASCII := 0
+	for i := max(pos-longSentenceDetectionLimit, 0); i < min(pos+longSentenceDetectionLimit, len(results)); i++ {
+		if results[i].runeType == runeTypeBasic && results[i].runeChar != ' ' {
+			countBasic++
+		}
+		if results[i].runeType == runeTypeNonASCII || results[i].runeType == runeTypeAmbiguous {
+			countNonASCII++
+		}
+	}
+	countChar := countBasic + countNonASCII
+	// many non-ASCII runes around, it seems to be a sentence,
+	// don't handle the invisible/ambiguous chars in it, otherwise it will be too noisy
+	return countChar != 0 && countNonASCII*100/countChar >= 50
+}
+
+func (e *escapeStreamer) analyzeDetectResults(results []detectResult) {
+	for i := range results {
+		res := &results[i]
+		if res.runeType == runeTypeInvisible || res.runeType == runeTypeAmbiguous {
+			leftIsNonASCII := i > 0 && (results[i-1].runeType == runeTypeNonASCII || results[i-1].runeType == runeTypeAmbiguous)
+			rightIsNonASCII := i < len(results)-1 && (results[i+1].runeType == runeTypeNonASCII || results[i+1].runeType == runeTypeAmbiguous)
+			surroundingNonASCII := leftIsNonASCII || rightIsNonASCII
+			if !surroundingNonASCII {
+				if len(results) < longSentenceDetectionLimit {
+					res.needEscape = setting.UI.AmbiguousUnicodeDetection
+				} else if !e.possibleLongSentence(results, i) {
+					res.needEscape = setting.UI.AmbiguousUnicodeDetection
+				}
+			}
+		}
+	}
+}
+
+func (e *escapeStreamer) detectAndWriteRunes(part []byte) error {
+	results := e.detectRunes(part)
+	e.analyzeDetectResults(results)
+	return e.writeDetectResults(part, results)
+}
+
+func (e *htmlChunkReader) readRunes() (parts [][]byte, partInTag []bool, _ error) {
+	// we have read everything, eof
+	if e.readErr != nil && len(e.readBuf) == 0 {
+		return nil, nil, e.readErr
+	}
+
+	// not eof, and the there is space in the buffer, try to read more data
+	if e.readErr == nil && len(e.readBuf) <= cap(e.readBuf)*3/4 {
+		n, err := e.in.Read(e.readBuf[len(e.readBuf):cap(e.readBuf)])
+		e.readErr = err
+		e.readBuf = e.readBuf[:len(e.readBuf)+n]
+	}
+	if len(e.readBuf) == 0 {
+		return nil, nil, e.readErr
+	}
+
+	// try to exact tag parts and content parts
 	pos := 0
-	if len(data) > len(UTF8BOM) && data[:len(UTF8BOM)] == string(UTF8BOM) {
-		_, _ = sb.WriteString(data[:len(UTF8BOM)])
-		pos = len(UTF8BOM)
-	}
-	dataBytes := []byte(data)
-	for pos < len(data) {
-		nextIdxs := defaultWordRegexp.FindStringIndex(data[pos:])
-		if nextIdxs == nil {
-			until = len(data)
-			next = until
-		} else {
-			until = min(nextIdxs[0]+pos, len(data))
-			next = min(nextIdxs[1]+pos, len(data))
-		}
-
-		// from pos until we know that the runes are not \r\t\n or even ' '
-		n := next - until
-		runes := make([]rune, 0, n)
-		positions := make([]int, 0, n+1)
-
-		for pos < until {
-			r, sz := utf8.DecodeRune(dataBytes[pos:])
-			positions = positions[:0]
-			positions = append(positions, pos, pos+sz)
-			types, confusables, _ := e.runeTypes(r)
-			if err := e.handleRunes(dataBytes, []rune{r}, positions, types, confusables, sb); err != nil {
-				return err
-			}
-			pos += sz
-		}
-
-		for i := pos; i < next; {
-			r, sz := utf8.DecodeRune(dataBytes[i:])
-			runes = append(runes, r)
-			positions = append(positions, i)
-			i += sz
-		}
-		positions = append(positions, next)
-		types, confusables, runeCounts := e.runeTypes(runes...)
-		if runeCounts.needsEscape() {
-			if err := e.handleRunes(dataBytes, runes, positions, types, confusables, sb); err != nil {
-				return err
+	for pos < len(e.readBuf) {
+		var curPartEnd int
+		nextInTag := e.curInTag
+		if e.curInTag {
+			// if cur part is in tag, try to find the tag close char '>'
+			idx := bytes.IndexByte(e.readBuf[pos:], '>')
+			if idx == -1 {
+				// if no tag close char, then the whole buffer is in tag
+				curPartEnd = len(e.readBuf)
+			} else {
+				// tag part ends, switch to content part
+				curPartEnd = pos + idx + 1
+				nextInTag = !nextInTag
 			}
 		} else {
-			_, _ = sb.Write(dataBytes[pos:next])
+			// if cur part is in content, try to find the tag open char '<'
+			idx := bytes.IndexByte(e.readBuf[pos:], '<')
+			if idx == -1 {
+				// if no tag open char, then the whole buffer is in content
+				curPartEnd = len(e.readBuf)
+			} else {
+				// content part ends, switch to tag part
+				curPartEnd = pos + idx
+				nextInTag = !nextInTag
+			}
+		}
+
+		curPartLen := curPartEnd - pos
+		if curPartLen == 0 {
+			// if cur part is empty, only need to switch the part type
+			if e.curInTag == nextInTag {
+				panic("impossible, curPartLen is 0 but the part in tag status is not switched")
+			}
+			e.curInTag = nextInTag
+			continue
+		}
+
+		// now, curPartLen can't be 0
+		curPart := make([]byte, curPartLen)
+		copy(curPart, e.readBuf[pos:curPartEnd])
+		// now we get the curPart bytes, but we can't directly use it, the last rune in it might have been cut
+		// try to decode the last rune, if it's invalid, then we cut the last byte and try again until we get a valid rune or no byte left
+		for i := curPartLen - 1; i >= 0; i-- {
+			last, lastSize := utf8.DecodeRune(curPart[i:])
+			if last == utf8.RuneError && lastSize == 1 {
+				curPartLen--
+			} else {
+				curPartLen += lastSize - 1
+				break
+			}
+		}
+		if curPartLen == 0 {
+			// actually it's impossible that the part doesn't contain any valid rune,
+			// the only case is that the cap(readBuf) is too small, or the origin contain indeed doesn't contain any valid rune
+			// * try to leave the last 4 bytes (possible longest utf-8 encoding) to next round
+			// * at least consume 1 byte to avoid infinite loop
+			curPartLen = max(len(curPart)-utf8.UTFMax, 1)
+		}
+
+		// if curPartLen is not the same as curPart, it means we have cut some bytes,
+		// need to wait for more data if not eof
+		trailingCorrupted := curPartLen != len(curPart)
+
+		// finally, we get the real part we need
+		curPart = curPart[:curPartLen]
+		parts = append(parts, curPart)
+		partInTag = append(partInTag, e.curInTag)
+
+		pos += curPartLen
+		e.curInTag = nextInTag
+
+		if trailingCorrupted && e.readErr == nil {
+			// if the last part is corrupted, and we haven't reach eof, then we need to wait for more data to get the complete part
+			break
 		}
-		pos = next
 	}
-	if sb.Len() > 0 {
-		if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
+
+	copy(e.readBuf, e.readBuf[pos:])
+	e.readBuf = e.readBuf[:len(e.readBuf)-pos]
+	return parts, partInTag, nil
+}
+
+func (e *escapeStreamer) writeDetectResults(data []byte, results []detectResult) error {
+	lastWriteRawIdx := -1
+	for idx := range results {
+		res := &results[idx]
+		if !res.needEscape {
+			if lastWriteRawIdx == -1 {
+				lastWriteRawIdx = idx
+			}
+			continue
+		}
+
+		if lastWriteRawIdx != -1 {
+			if _, err := e.out.Write(data[results[lastWriteRawIdx].position:res.position]); err != nil {
+				return err
+			}
+			lastWriteRawIdx = -1
+		}
+		switch res.runeType {
+		case runeTypeBroken:
+			if err := e.writeBrokenRune(data[res.position : res.position+res.runeSize]); err != nil {
+				return err
+			}
+		case runeTypeAmbiguous:
+			if err := e.writeAmbiguousRune(res.runeChar, res.confusable); err != nil {
+				return err
+			}
+		case runeTypeInvisible:
+			if err := e.writeInvisibleRune(res.runeChar); err != nil {
+				return err
+			}
+		case runeTypeControlChar:
+			if err := e.writeControlRune(res.runeChar); err != nil {
+				return err
+			}
+		default:
+			panic("unreachable")
+		}
+	}
+	if lastWriteRawIdx != -1 {
+		lastResult := results[len(results)-1]
+		if _, err := e.out.Write(data[results[lastWriteRawIdx].position : lastResult.position+lastResult.runeSize]); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func (e *escapeStreamer) handleRunes(data []byte, runes []rune, positions []int, types []runeType, confusables []rune, sb *strings.Builder) error {
-	for i, r := range runes {
-		switch types[i] {
-		case brokenRuneType:
-			if sb.Len() > 0 {
-				if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
-					return err
-				}
-				sb.Reset()
-			}
-			end := positions[i+1]
-			start := positions[i]
-			if err := e.brokenRune(data[start:end]); err != nil {
-				return err
-			}
-		case ambiguousRuneType:
-			if sb.Len() > 0 {
-				if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
-					return err
-				}
-				sb.Reset()
-			}
-			if err := e.ambiguousRune(r, confusables[0]); err != nil {
-				return err
-			}
-			confusables = confusables[1:]
-		case invisibleRuneType:
-			if sb.Len() > 0 {
-				if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
-					return err
-				}
-				sb.Reset()
-			}
-			if err := e.invisibleRune(r); err != nil {
-				return err
-			}
-		default:
-			_, _ = sb.WriteRune(r)
-		}
-	}
-	return nil
+func (e *escapeStreamer) writeBrokenRune(_ []byte) (err error) {
+	// Although we'd like to use the original bytes to display (show the real broken content to users),
+	// however, when this "escape stream" module is applied to the content, the content has already been processed by other modules.
+	// So the invalid bytes just can't be kept till this step, in most (all) cases, the only thing we see here is utf8.RuneError
+	_, err = io.WriteString(e.out, `<span class="broken-code-point"><3E></span>`)
+	return err
 }
 
-func (e *escapeStreamer) brokenRune(bs []byte) error {
-	e.escaped.Escaped = true
-	e.escaped.HasBadRunes = true
-
-	if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
-		Key: "class",
-		Val: "broken-code-point",
-	}); err != nil {
+func (e *escapeStreamer) writeEscapedCharHTML(tag1, attr, tag2, content, tag3 string) (err error) {
+	_, err = io.WriteString(e.out, tag1)
+	if err != nil {
 		return err
 	}
-	if err := e.PassthroughHTMLStreamer.Text(fmt.Sprintf("<%X>", bs)); err != nil {
+	_, err = io.WriteString(e.out, html.EscapeString(attr))
+	if err != nil {
 		return err
 	}
-
-	return e.PassthroughHTMLStreamer.EndTag("span")
+	_, err = io.WriteString(e.out, tag2)
+	if err != nil {
+		return err
+	}
+	_, err = io.WriteString(e.out, html.EscapeString(content))
+	if err != nil {
+		return err
+	}
+	_, err = io.WriteString(e.out, tag3)
+	return err
 }
 
-func (e *escapeStreamer) ambiguousRune(r, c rune) error {
+func runeToHex(r rune) string {
+	return fmt.Sprintf("[U+%04X]", r)
+}
+
+func (e *escapeStreamer) writeAmbiguousRune(r, c rune) (err error) {
 	e.escaped.Escaped = true
 	e.escaped.HasAmbiguous = true
-
-	if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
-		Key: "class",
-		Val: "ambiguous-code-point",
-	}, html.Attribute{
-		Key: "data-tooltip-content",
-		Val: e.locale.TrString("repo.ambiguous_character", r, c),
-	}); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
-		Key: "class",
-		Val: "char",
-	}); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.Text(string(r)); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.EndTag("span"); err != nil {
-		return err
-	}
-
-	return e.PassthroughHTMLStreamer.EndTag("span")
+	return e.writeEscapedCharHTML(
+		`<span class="ambiguous-code-point" data-tooltip-content="`,
+		e.locale.TrString("repo.ambiguous_character", string(r)+" "+runeToHex(r), string(c)+" "+runeToHex(c)),
+		`"><span class="char">`,
+		string(r),
+		`</span></span>`,
+	)
 }
 
-func (e *escapeStreamer) invisibleRune(r rune) error {
+func (e *escapeStreamer) writeInvisibleRune(r rune) error {
 	e.escaped.Escaped = true
 	e.escaped.HasInvisible = true
-
-	if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
-		Key: "class",
-		Val: "escaped-code-point",
-	}, html.Attribute{
-		Key: "data-escaped",
-		Val: fmt.Sprintf("[U+%04X]", r),
-	}); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
-		Key: "class",
-		Val: "char",
-	}); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.Text(string(r)); err != nil {
-		return err
-	}
-	if err := e.PassthroughHTMLStreamer.EndTag("span"); err != nil {
-		return err
-	}
-
-	return e.PassthroughHTMLStreamer.EndTag("span")
+	return e.writeEscapedCharHTML(
+		`<span class="escaped-code-point" data-escaped="`,
+		runeToHex(r),
+		`"><span class="char">`,
+		string(r),
+		`</span></span>`,
+	)
 }
 
-type runeCountType struct {
-	numBasicRunes                int
-	numNonConfusingNonBasicRunes int
-	numAmbiguousRunes            int
-	numInvisibleRunes            int
-	numBrokenRunes               int
+func (e *escapeStreamer) writeControlRune(r rune) error {
+	var display string
+	if r >= 0 && r <= 0x1f {
+		display = string(0x2400 + r)
+	} else if r == 0x7f {
+		display = string(rune(0x2421))
+	} else {
+		display = runeToHex(r)
+	}
+	return e.writeEscapedCharHTML(
+		`<span class="broken-code-point" data-escaped="`,
+		display,
+		`"><span class="char">`,
+		string(r),
+		`</span></span>`,
+	)
 }
 
-func (counts runeCountType) needsEscape() bool {
-	if counts.numBrokenRunes > 0 {
-		return true
-	}
-	if counts.numBasicRunes == 0 &&
-		counts.numNonConfusingNonBasicRunes > 0 {
-		return false
-	}
-	return counts.numAmbiguousRunes > 0 || counts.numInvisibleRunes > 0
+type detectResult struct {
+	runeChar   rune
+	runeType   int
+	runeSize   int
+	position   int
+	confusable rune
+	needEscape bool
 }
 
-type runeType int
-
 const (
-	basicASCIIRuneType runeType = iota // <- This is technically deadcode but its self-documenting so it should stay
-	brokenRuneType
-	nonBasicASCIIRuneType
-	ambiguousRuneType
-	invisibleRuneType
+	runeTypeBasic int = iota
+	runeTypeBroken
+	runeTypeNonASCII
+	runeTypeAmbiguous
+	runeTypeInvisible
+	runeTypeControlChar
 )
 
-func (e *escapeStreamer) runeTypes(runes ...rune) (types []runeType, confusables []rune, runeCounts runeCountType) {
-	types = make([]runeType, len(runes))
-	for i, r := range runes {
-		var confusable rune
+func (e *escapeStreamer) detectRunes(data []byte) []detectResult {
+	runeCount := utf8.RuneCount(data)
+	results := make([]detectResult, runeCount)
+	invisibleRangeTable := globalVars().invisibleRangeTable
+	var i int
+	var confusable rune
+	for pos := 0; pos < len(data); i++ {
+		r, runeSize := utf8.DecodeRune(data[pos:])
+		results[i].runeChar = r
+		results[i].runeSize = runeSize
+		results[i].position = pos
+		pos += runeSize
+
 		switch {
 		case r == utf8.RuneError:
-			types[i] = brokenRuneType
-			runeCounts.numBrokenRunes++
-		case r == ' ' || r == '\t' || r == '\n':
-			runeCounts.numBasicRunes++
-		case e.allowed[r]:
-			if r > 0x7e || r < 0x20 {
-				types[i] = nonBasicASCIIRuneType
-				runeCounts.numNonConfusingNonBasicRunes++
-			} else {
-				runeCounts.numBasicRunes++
+			results[i].runeType = runeTypeBroken
+			results[i].needEscape = true
+		case r == ' ' || r == '\t' || r == '\n' || e.allowed[r]:
+			results[i].runeType = runeTypeBasic
+			if r >= 0x80 {
+				results[i].runeType = runeTypeNonASCII
 			}
-		case unicode.Is(InvisibleRanges, r):
-			types[i] = invisibleRuneType
-			runeCounts.numInvisibleRunes++
-		case unicode.IsControl(r):
-			types[i] = invisibleRuneType
-			runeCounts.numInvisibleRunes++
+		case r < 0x20 || r == 0x7f:
+			results[i].runeType = runeTypeControlChar
+			results[i].needEscape = true
+		case unicode.Is(invisibleRangeTable, r):
+			results[i].runeType = runeTypeInvisible
+			// not sure about results[i].needEscape, will be detected separately
 		case isAmbiguous(r, &confusable, e.ambiguousTables...):
-			confusables = append(confusables, confusable)
-			types[i] = ambiguousRuneType
-			runeCounts.numAmbiguousRunes++
-		case r > 0x7e || r < 0x20:
-			types[i] = nonBasicASCIIRuneType
-			runeCounts.numNonConfusingNonBasicRunes++
-		default:
-			runeCounts.numBasicRunes++
+			results[i].runeType = runeTypeAmbiguous
+			results[i].confusable = confusable
+			// not sure about results[i].needEscape, will be detected separately
+		case r >= 0x80:
+			results[i].runeType = runeTypeNonASCII
+		default: // details to basic runes
 		}
 	}
-	return types, confusables, runeCounts
+	return results
 }

modules/charset/escape_test.go

@@ -4,7 +4,6 @@
 package charset
 
 import (
-	"regexp"
 	"strings"
 	"testing"
 
@@ -13,6 +12,7 @@ import (
 	"code.gitea.io/gitea/modules/translation"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 type escapeControlTest struct {
@@ -57,24 +57,24 @@ var escapeControlTests = []escapeControlTest{
 		status: EscapeStatus{},
 	},
 	{
-		name:   "hebrew",
+		name:   "hebrew", // old test was wrong, such text shouldn't be escaped
 		text:   "עד תקופת יוון העתיקה היה העיסוק במתמטיקה תכליתי בלבד: היא שימשה כאוסף של נוסחאות לחישוב קרקע, אוכלוסין וכו'. פריצת הדרך של היוונים, פרט לתרומותיהם הגדולות לידע המתמטי, הייתה בלימוד המתמטיקה כשלעצמה, מתוקף ערכה הרוחני. יחסם של חלק מהיוונים הקדמונים למתמטיקה היה דתי - למשל, הכת שאסף סביבו פיתגורס האמינה כי המתמטיקה היא הבסיס לכל הדברים. היוונים נחשבים ליוצרי מושג ההוכחה המתמטית, וכן לראשונים שעסקו במתמטיקה לשם עצמה, כלומר כתחום מחקרי עיוני ומופשט ולא רק כעזר שימושי. עם זאת, לצדה",
-		result: `עד תקופת <span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">י</span></span><span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ו</span></span><span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ו</span></span><span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ן</span></span> העתיקה היה העיסוק במתמטיקה תכליתי בלבד: היא שימשה כאוסף של נוסחאות לחישוב קרקע, אוכלוסין וכו&#39;. פריצת הדרך של היוונים, פרט לתרומותיהם הגדולות לידע המתמטי, הייתה בלימוד המתמטיקה כשלעצמה, מתוקף ערכה הרוחני. יחסם של חלק מהיוונים הקדמונים למתמטיקה היה דתי - למשל, הכת שאסף סביבו פיתגורס האמינה כי המתמטיקה היא הבסיס לכל הדברים. היוונים נחשבים ליוצרי מושג ההוכחה המתמטית, וכן לראשונים שעסקו במתמטיקה לשם עצמה, כלומר כתחום מחקרי עיוני ומופשט ולא רק כעזר שימושי. עם זאת, לצדה`,
-		status: EscapeStatus{Escaped: true, HasAmbiguous: true},
+		result: "עד תקופת יוון העתיקה היה העיסוק במתמטיקה תכליתי בלבד: היא שימשה כאוסף של נוסחאות לחישוב קרקע, אוכלוסין וכו'. פריצת הדרך של היוונים, פרט לתרומותיהם הגדולות לידע המתמטי, הייתה בלימוד המתמטיקה כשלעצמה, מתוקף ערכה הרוחני. יחסם של חלק מהיוונים הקדמונים למתמטיקה היה דתי - למשל, הכת שאסף סביבו פיתגורס האמינה כי המתמטיקה היא הבסיס לכל הדברים. היוונים נחשבים ליוצרי מושג ההוכחה המתמטית, וכן לראשונים שעסקו במתמטיקה לשם עצמה, כלומר כתחום מחקרי עיוני ומופשט ולא רק כעזר שימושי. עם זאת, לצדה",
+		status: EscapeStatus{},
 	},
 	{
-		name: "more hebrew",
+		name: "more hebrew", // old test was wrong, such text shouldn't be escaped
 		text: `בתקופה מאוחרת יותר, השתמשו היוונים בשיטת סימון מתקדמת יותר, שבה הוצגו המספרים לפי 22 אותיות האלפבית היווני. לסימון המספרים בין 1 ל-9 נקבעו תשע האותיות הראשונות, בתוספת גרש ( ' ) בצד ימין של האות, למעלה; תשע האותיות הבאות ייצגו את העשרות מ-10 עד 90, והבאות את המאות. לסימון הספרות בין 1000 ל-900,000, השתמשו היוונים באותן אותיות, אך הוסיפו לאותיות את הגרש דווקא מצד שמאל של האותיות, למטה. ממיליון ומעלה, כנראה השתמשו היוונים בשני תגים במקום אחד.
 
 			המתמטיקאי הבולט הראשון ביוון העתיקה, ויש האומרים בתולדות האנושות, הוא תאלס (624 לפנה"ס - 546 לפנה"ס בקירוב).[1] לא יהיה זה משולל יסוד להניח שהוא האדם הראשון שהוכיח משפט מתמטי, ולא רק גילה אותו. תאלס הוכיח שישרים מקבילים חותכים מצד אחד של שוקי זווית קטעים בעלי יחסים שווים (משפט תאלס הראשון), שהזווית המונחת על קוטר במעגל היא זווית ישרה (משפט תאלס השני), שהקוטר מחלק את המעגל לשני חלקים שווים, ושזוויות הבסיס במשולש שווה-שוקיים שוות זו לזו. מיוחסות לו גם שיטות למדידת גובהן של הפירמידות בעזרת מדידת צילן ולקביעת מיקומה של ספינה הנראית מן החוף.
 
 			בשנים 582 לפנה"ס עד 496 לפנה"ס, בקירוב, חי מתמטיקאי חשוב במיוחד - פיתגורס. המקורות הראשוניים עליו מועטים, וההיסטוריונים מתקשים להפריד את העובדות משכבת המסתורין והאגדות שנקשרו בו. ידוע שסביבו התקבצה האסכולה הפיתגוראית מעין כת פסבדו-מתמטית שהאמינה ש"הכל מספר", או ליתר דיוק הכל ניתן לכימות, וייחסה למספרים משמעויות מיסטיות. ככל הנראה הפיתגוראים ידעו לבנות את הגופים האפלטוניים, הכירו את הממוצע האריתמטי, הממוצע הגאומטרי והממוצע ההרמוני והגיעו להישגים חשובים נוספים. ניתן לומר שהפיתגוראים גילו את היותו של השורש הריבועי של 2, שהוא גם האלכסון בריבוע שאורך צלעותיו 1, אי רציונלי, אך תגליתם הייתה למעשה רק שהקטעים "חסרי מידה משותפת", ומושג המספר האי רציונלי מאוחר יותר.[2] אזכור ראשון לקיומם של קטעים חסרי מידה משותפת מופיע בדיאלוג "תאיטיטוס" של אפלטון, אך רעיון זה היה מוכר עוד קודם לכן, במאה החמישית לפנה"ס להיפאסוס, בן האסכולה הפיתגוראית, ואולי לפיתגורס עצמו.[3]`,
-		result: `בתקופה מאוחרת יותר, השתמשו היוונים בשיטת סימון מתקדמת יותר, שבה הוצגו המספרים לפי 22 אותיות האלפבית היווני. לסימון המספרים בין 1 ל-9 נקבעו תשע האותיות הראשונות, בתוספת גרש ( &#39; ) בצד ימין של האות, למעלה; תשע האותיות הבאות ייצגו את העשרות מ-10 עד 90, והבאות את המאות. לסימון הספרות בין 1000 ל-900,000, השתמשו היוונים באותן אותיות, אך הוסיפו לאותיות את הגרש דווקא מצד שמאל של האותיות, למטה. ממיליון ומעלה, כנראה השתמשו היוונים בשני תגים במקום אחד.
+		result: `בתקופה מאוחרת יותר, השתמשו היוונים בשיטת סימון מתקדמת יותר, שבה הוצגו המספרים לפי 22 אותיות האלפבית היווני. לסימון המספרים בין 1 ל-9 נקבעו תשע האותיות הראשונות, בתוספת גרש ( ' ) בצד ימין של האות, למעלה; תשע האותיות הבאות ייצגו את העשרות מ-10 עד 90, והבאות את המאות. לסימון הספרות בין 1000 ל-900,000, השתמשו היוונים באותן אותיות, אך הוסיפו לאותיות את הגרש דווקא מצד שמאל של האותיות, למטה. ממיליון ומעלה, כנראה השתמשו היוונים בשני תגים במקום אחד.
 
-			המתמטיקאי הבולט הראשון ביוון העתיקה, ויש האומרים בתולדות האנושות, הוא תאלס (624 לפנה&#34;<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ס</span></span> - 546 לפנה&#34;<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ס</span></span> בקירוב).[1] לא יהיה זה משולל יסוד להניח שהוא האדם הראשון שהוכיח משפט מתמטי, ולא רק גילה אותו. תאלס הוכיח שישרים מקבילים חותכים מצד אחד של שוקי זווית קטעים בעלי יחסים שווים (משפט תאלס הראשון), שהזווית המונחת על קוטר במעגל היא זווית ישרה (משפט תאלס השני), שהקוטר מחלק את המעגל לשני חלקים שווים, ושזוויות הבסיס במשולש שווה-שוקיים שוות זו לזו. מיוחסות לו גם שיטות למדידת גובהן של הפירמידות בעזרת מדידת צילן ולקביעת מיקומה של ספינה הנראית מן החוף.
+			המתמטיקאי הבולט הראשון ביוון העתיקה, ויש האומרים בתולדות האנושות, הוא תאלס (624 לפנה"ס - 546 לפנה"ס בקירוב).[1] לא יהיה זה משולל יסוד להניח שהוא האדם הראשון שהוכיח משפט מתמטי, ולא רק גילה אותו. תאלס הוכיח שישרים מקבילים חותכים מצד אחד של שוקי זווית קטעים בעלי יחסים שווים (משפט תאלס הראשון), שהזווית המונחת על קוטר במעגל היא זווית ישרה (משפט תאלס השני), שהקוטר מחלק את המעגל לשני חלקים שווים, ושזוויות הבסיס במשולש שווה-שוקיים שוות זו לזו. מיוחסות לו גם שיטות למדידת גובהן של הפירמידות בעזרת מדידת צילן ולקביעת מיקומה של ספינה הנראית מן החוף.
 
-			בשנים 582 לפנה&#34;<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ס</span></span> עד 496 לפנה&#34;<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ס</span></span>, בקירוב, חי מתמטיקאי חשוב במיוחד - פיתגורס. המקורות הראשוניים עליו מועטים, וההיסטוריונים מתקשים להפריד את העובדות משכבת המסתורין והאגדות שנקשרו בו. ידוע שסביבו התקבצה האסכולה הפיתגוראית מעין כת פסבדו-מתמטית שהאמינה ש&#34;הכל מספר&#34;, או ליתר דיוק הכל ניתן לכימות, וייחסה למספרים משמעויות מיסטיות. ככל הנראה הפיתגוראים ידעו לבנות את הגופים האפלטוניים, הכירו את הממוצע האריתמטי, הממוצע הגאומטרי והממוצע ההרמוני והגיעו להישגים חשובים נוספים. ניתן לומר שהפיתגוראים גילו את היותו של השורש הריבועי של 2, שהוא גם האלכסון בריבוע שאורך צלעותיו 1, אי רציונלי, אך תגליתם הייתה למעשה רק שהקטעים &#34;חסרי מידה משותפת&#34;, ומושג המספר האי רציונלי מאוחר יותר.[2] אזכור ראשון לקיומם של קטעים חסרי מידה משותפת מופיע בדיאלוג &#34;תאיטיטוס&#34; של אפלטון, אך רעיון זה היה מוכר עוד קודם לכן, במאה החמישית לפנה&#34;<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character"><span class="char">ס</span></span> להיפאסוס, בן האסכולה הפיתגוראית, ואולי לפיתגורס עצמו.[3]`,
-		status: EscapeStatus{Escaped: true, HasAmbiguous: true},
+			בשנים 582 לפנה"ס עד 496 לפנה"ס, בקירוב, חי מתמטיקאי חשוב במיוחד - פיתגורס. המקורות הראשוניים עליו מועטים, וההיסטוריונים מתקשים להפריד את העובדות משכבת המסתורין והאגדות שנקשרו בו. ידוע שסביבו התקבצה האסכולה הפיתגוראית מעין כת פסבדו-מתמטית שהאמינה ש"הכל מספר", או ליתר דיוק הכל ניתן לכימות, וייחסה למספרים משמעויות מיסטיות. ככל הנראה הפיתגוראים ידעו לבנות את הגופים האפלטוניים, הכירו את הממוצע האריתמטי, הממוצע הגאומטרי והממוצע ההרמוני והגיעו להישגים חשובים נוספים. ניתן לומר שהפיתגוראים גילו את היותו של השורש הריבועי של 2, שהוא גם האלכסון בריבוע שאורך צלעותיו 1, אי רציונלי, אך תגליתם הייתה למעשה רק שהקטעים "חסרי מידה משותפת", ומושג המספר האי רציונלי מאוחר יותר.[2] אזכור ראשון לקיומם של קטעים חסרי מידה משותפת מופיע בדיאלוג "תאיטיטוס" של אפלטון, אך רעיון זה היה מוכר עוד קודם לכן, במאה החמישית לפנה"ס להיפאסוס, בן האסכולה הפיתגוראית, ואולי לפיתגורס עצמו.[3]`,
+		status: EscapeStatus{},
 	},
 	{
 		name: "Mixed RTL+LTR",
@@ -111,7 +111,7 @@ then resh (ר), and finally heh (ה) (which should appear leftmost).`,
 	{
 		name:   "CVE testcase",
 		text:   "if access_level != \"user\u202E \u2066// Check if admin\u2069 \u2066\" {",
-		result: `if access_level != &#34;user<span class="escaped-code-point" data-escaped="[U+202E]"><span class="char">` + "\u202e" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>// Check if admin<span class="escaped-code-point" data-escaped="[U+2069]"><span class="char">` + "\u2069" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>&#34; {`,
+		result: `if access_level != "user<span class="escaped-code-point" data-escaped="[U+202E]"><span class="char">` + "\u202e" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>// Check if admin<span class="escaped-code-point" data-escaped="[U+2069]"><span class="char">` + "\u2069" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>" {`,
 		status: EscapeStatus{Escaped: true, HasInvisible: true},
 	},
 	{
@@ -123,7 +123,7 @@ then resh (ר), and finally heh (ה) (which should appear leftmost).`,
 		result: `Many computer programs fail to display bidirectional text correctly.
 			For example, the Hebrew name Sarah ` + "\u2067" + `שרה` + "\u2066\n" +
 			`sin (ש) (which appears rightmost), then resh (ר), and finally heh (ה) (which should appear leftmost).` +
-			"\n" + `if access_level != &#34;user<span class="escaped-code-point" data-escaped="[U+202E]"><span class="char">` + "\u202e" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>// Check if admin<span class="escaped-code-point" data-escaped="[U+2069]"><span class="char">` + "\u2069" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>&#34; {` + "\n",
+			"\n" + `if access_level != "user<span class="escaped-code-point" data-escaped="[U+202E]"><span class="char">` + "\u202e" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>// Check if admin<span class="escaped-code-point" data-escaped="[U+2069]"><span class="char">` + "\u2069" + `</span></span> <span class="escaped-code-point" data-escaped="[U+2066]"><span class="char">` + "\u2066" + `</span></span>" {` + "\n",
 		status: EscapeStatus{Escaped: true, HasInvisible: true},
 	},
 	{
@@ -134,38 +134,22 @@ then resh (ר), and finally heh (ה) (which should appear leftmost).`,
 		result: "\xef\xbb\xbftest",
 		status: EscapeStatus{},
 	},
+	{
+		name:   "ambiguous",
+		text:   "O𝐾",
+		result: `O<span class="ambiguous-code-point" data-tooltip-content="repo.ambiguous_character:𝐾 [U+1D43E],K [U+004B]"><span class="char">𝐾</span></span>`,
+		status: EscapeStatus{Escaped: true, HasAmbiguous: true},
+	},
 }
 
 func TestEscapeControlReader(t *testing.T) {
-	// add some control characters to the tests
-	tests := make([]escapeControlTest, 0, len(escapeControlTests)*3)
-	copy(tests, escapeControlTests)
-
-	// if there is a BOM, we should keep the BOM
-	addPrefix := func(prefix, s string) string {
-		if strings.HasPrefix(s, "\xef\xbb\xbf") {
-			return s[:3] + prefix + s[3:]
-		}
-		return prefix + s
-	}
-	for _, test := range escapeControlTests {
-		test.name += " (+Control)"
-		test.text = addPrefix("\u001E", test.text)
-		test.result = addPrefix(`<span class="escaped-code-point" data-escaped="[U+001E]"><span class="char">`+"\u001e"+`</span></span>`, test.result)
-		test.status.Escaped = true
-		test.status.HasInvisible = true
-		tests = append(tests, test)
-	}
-
-	re := regexp.MustCompile(`repo.ambiguous_character:\d+,\d+`) // simplify the output for the tests, remove the translation variants
-	for _, tt := range tests {
+	for _, tt := range escapeControlTests {
 		t.Run(tt.name, func(t *testing.T) {
 			output := &strings.Builder{}
 			status, err := EscapeControlReader(strings.NewReader(tt.text), output, &translation.MockLocale{})
 			assert.NoError(t, err)
 			assert.Equal(t, tt.status, *status)
 			outStr := output.String()
-			outStr = re.ReplaceAllString(outStr, "repo.ambiguous_character")
 			assert.Equal(t, tt.result, outStr)
 		})
 	}
@@ -179,3 +163,50 @@ func TestSettingAmbiguousUnicodeDetection(t *testing.T) {
 	_, out = EscapeControlHTML("a test", &translation.MockLocale{})
 	assert.EqualValues(t, `a test`, out)
 }
+
+func TestHTMLChunkReader(t *testing.T) {
+	type textPart struct {
+		text  string
+		isTag bool
+	}
+	testReadChunks := func(t *testing.T, chunkSize int, input string, expected []textPart) {
+		r := &htmlChunkReader{in: strings.NewReader(input), readBuf: make([]byte, 0, chunkSize)}
+		var results []textPart
+		for {
+			parts, partIsTag, err := r.readRunes()
+			if err != nil {
+				break
+			}
+			for i, part := range parts {
+				results = append(results, textPart{string(part), partIsTag[i]})
+			}
+		}
+		assert.Equal(t, expected, results, "chunk size: %d, input: %s", chunkSize, input)
+	}
+
+	testReadChunks(t, 10, "abc<def>ghi", []textPart{
+		{text: "abc", isTag: false},
+		{text: "<def>", isTag: true},
+		{text: "gh", isTag: false},
+		// -- chunk
+		{text: "i", isTag: false},
+	})
+
+	testReadChunks(t, 10, "<abc><def>ghi", []textPart{
+		{text: "<abc>", isTag: true},
+		{text: "<def>", isTag: true},
+		// -- chunk
+		{text: "ghi", isTag: false},
+	})
+
+	rune1, rune2, rune3, rune4 := "A", "é", "啊", "🌞"
+	require.Len(t, rune1, 1)
+	require.Len(t, rune2, 2)
+	require.Len(t, rune3, 3)
+	require.Len(t, rune4, 4)
+	input := "<" + rune1 + rune2 + rune3 + rune4 + ">" + rune1 + rune2 + rune3 + rune4
+	testReadChunks(t, 4, input, []textPart{{"<Aé", true}, {"啊", true}, {"🌞", true}, {">", true}, {"Aé", false}, {"啊", false}, {"🌞", false}})
+	testReadChunks(t, 5, input, []textPart{{"<Aé", true}, {"啊", true}, {"🌞>", true}, {"Aé", false}, {"啊", false}, {"🌞", false}})
+	testReadChunks(t, 6, input, []textPart{{"<Aé", true}, {"啊", true}, {"🌞>", true}, {"A", false}, {"é啊", false}, {"🌞", false}})
+	testReadChunks(t, 7, input, []textPart{{"<Aé啊", true}, {"🌞>", true}, {"A", false}, {"é啊", false}, {"🌞", false}})
+}

modules/charset/generate/generate.go

@@ -5,37 +5,86 @@ package main
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
 	"go/format"
+	"log"
 	"os"
+	"sort"
 	"text/template"
+	"unicode"
+
+	"code.gitea.io/gitea/modules/json"
 
 	"golang.org/x/text/unicode/rangetable"
 )
 
+// ambiguous.json provides a one to one mapping of ambiguous characters to other characters
+// See https://github.com/hediet/vscode-unicode-data/blob/main/out/ambiguous.json
+
+type AmbiguousTable struct {
+	Confusable []rune
+	With       []rune
+	Locale     string
+	RangeTable *unicode.RangeTable
+}
+
+type RunePair struct {
+	Confusable rune
+	With       rune
+}
+
 // InvisibleRunes these are runes that vscode has assigned to be invisible
 // See https://github.com/hediet/vscode-unicode-data
 var InvisibleRunes = []rune{
 	9, 10, 11, 12, 13, 32, 127, 160, 173, 847, 1564, 4447, 4448, 6068, 6069, 6155, 6156, 6157, 6158, 7355, 7356, 8192, 8193, 8194, 8195, 8196, 8197, 8198, 8199, 8200, 8201, 8202, 8203, 8204, 8205, 8206, 8207, 8234, 8235, 8236, 8237, 8238, 8239, 8287, 8288, 8289, 8290, 8291, 8292, 8293, 8294, 8295, 8296, 8297, 8298, 8299, 8300, 8301, 8302, 8303, 10240, 12288, 12644, 65024, 65025, 65026, 65027, 65028, 65029, 65030, 65031, 65032, 65033, 65034, 65035, 65036, 65037, 65038, 65039, 65279, 65440, 65520, 65521, 65522, 65523, 65524, 65525, 65526, 65527, 65528, 65532, 78844, 119155, 119156, 119157, 119158, 119159, 119160, 119161, 119162, 917504, 917505, 917506, 917507, 917508, 917509, 917510, 917511, 917512, 917513, 917514, 917515, 917516, 917517, 917518, 917519, 917520, 917521, 917522, 917523, 917524, 917525, 917526, 917527, 917528, 917529, 917530, 917531, 917532, 917533, 917534, 917535, 917536, 917537, 917538, 917539, 917540, 917541, 917542, 917543, 917544, 917545, 917546, 917547, 917548, 917549, 917550, 917551, 917552, 917553, 917554, 917555, 917556, 917557, 917558, 917559, 917560, 917561, 917562, 917563, 917564, 917565, 917566, 917567, 917568, 917569, 917570, 917571, 917572, 917573, 917574, 917575, 917576, 917577, 917578, 917579, 917580, 917581, 917582, 917583, 917584, 917585, 917586, 917587, 917588, 917589, 917590, 917591, 917592, 917593, 917594, 917595, 917596, 917597, 917598, 917599, 917600, 917601, 917602, 917603, 917604, 917605, 917606, 917607, 917608, 917609, 917610, 917611, 917612, 917613, 917614, 917615, 917616, 917617, 917618, 917619, 917620, 917621, 917622, 917623, 917624, 917625, 917626, 917627, 917628, 917629, 917630, 917631, 917760, 917761, 917762, 917763, 917764, 917765, 917766, 917767, 917768, 917769, 917770, 917771, 917772, 917773, 917774, 917775, 917776, 917777, 917778, 917779, 917780, 917781, 917782, 917783, 917784, 917785, 917786, 917787, 917788, 917789, 917790, 917791, 917792, 917793, 917794, 917795, 917796, 917797, 917798, 917799, 917800, 917801, 917802, 917803, 917804, 917805, 917806, 917807, 917808, 917809, 917810, 917811, 917812, 917813, 917814, 917815, 917816, 917817, 917818, 917819, 917820, 917821, 917822, 917823, 917824, 917825, 917826, 917827, 917828, 917829, 917830, 917831, 917832, 917833, 917834, 917835, 917836, 917837, 917838, 917839, 917840, 917841, 917842, 917843, 917844, 917845, 917846, 917847, 917848, 917849, 917850, 917851, 917852, 917853, 917854, 917855, 917856, 917857, 917858, 917859, 917860, 917861, 917862, 917863, 917864, 917865, 917866, 917867, 917868, 917869, 917870, 917871, 917872, 917873, 917874, 917875, 917876, 917877, 917878, 917879, 917880, 917881, 917882, 917883, 917884, 917885, 917886, 917887, 917888, 917889, 917890, 917891, 917892, 917893, 917894, 917895, 917896, 917897, 917898, 917899, 917900, 917901, 917902, 917903, 917904, 917905, 917906, 917907, 917908, 917909, 917910, 917911, 917912, 917913, 917914, 917915, 917916, 917917, 917918, 917919, 917920, 917921, 917922, 917923, 917924, 917925, 917926, 917927, 917928, 917929, 917930, 917931, 917932, 917933, 917934, 917935, 917936, 917937, 917938, 917939, 917940, 917941, 917942, 917943, 917944, 917945, 917946, 917947, 917948, 917949, 917950, 917951, 917952, 917953, 917954, 917955, 917956, 917957, 917958, 917959, 917960, 917961, 917962, 917963, 917964, 917965, 917966, 917967, 917968, 917969, 917970, 917971, 917972, 917973, 917974, 917975, 917976, 917977, 917978, 917979, 917980, 917981, 917982, 917983, 917984, 917985, 917986, 917987, 917988, 917989, 917990, 917991, 917992, 917993, 917994, 917995, 917996, 917997, 917998, 917999,
 }
 
-var verbose bool
-
-func main() {
-	flag.Usage = func() {
-		fmt.Fprintf(os.Stderr, `%s: Generate InvisibleRunesRange
-
-Usage: %[1]s [-v] [-o output.go]
-`, os.Args[0])
-		flag.PrintDefaults()
+func generateAmbiguous() {
+	bs, err := os.ReadFile("ambiguous.json")
+	if err != nil {
+		log.Fatalf("Unable to read, err: %v", err)
 	}
 
-	output := ""
-	flag.BoolVar(&verbose, "v", false, "verbose output")
-	flag.StringVar(&output, "o", "invisible_gen.go", "file to output to")
-	flag.Parse()
+	var unwrapped string
+	if err := json.Unmarshal(bs, &unwrapped); err != nil {
+		log.Fatalf("Unable to unwrap content in, err: %v", err)
+	}
 
+	fromJSON := map[string][]uint32{}
+	if err := json.Unmarshal([]byte(unwrapped), &fromJSON); err != nil {
+		log.Fatalf("Unable to unmarshal content in, err: %v", err)
+	}
+
+	tables := make([]*AmbiguousTable, 0, len(fromJSON))
+	for locale, chars := range fromJSON {
+		table := &AmbiguousTable{Locale: locale}
+		table.Confusable = make([]rune, 0, len(chars)/2)
+		table.With = make([]rune, 0, len(chars)/2)
+		pairs := make([]RunePair, len(chars)/2)
+		for i := 0; i < len(chars); i += 2 {
+			pairs[i/2].Confusable, pairs[i/2].With = rune(chars[i]), rune(chars[i+1])
+		}
+		sort.Slice(pairs, func(i, j int) bool {
+			return pairs[i].Confusable < pairs[j].Confusable
+		})
+		for _, pair := range pairs {
+			table.Confusable = append(table.Confusable, pair.Confusable)
+			table.With = append(table.With, pair.With)
+		}
+		table.RangeTable = rangetable.New(table.Confusable...)
+		tables = append(tables, table)
+	}
+	sort.Slice(tables, func(i, j int) bool {
+		return tables[i].Locale < tables[j].Locale
+	})
+	data := map[string]any{"Tables": tables}
+
+	if err := runTemplate(templateAmbiguous, "../ambiguous_gen.go", &data); err != nil {
+		log.Fatalf("Unable to run template: %v", err)
+	}
+}
+
+func generateInvisible() {
 	// First we filter the runes to remove
 	// <space><tab><newline>
 	filtered := make([]rune, 0, len(InvisibleRunes))
@@ -47,8 +96,8 @@ Usage: %[1]s [-v] [-o output.go]
 	}
 
 	table := rangetable.New(filtered...)
-	if err := runTemplate(generatorTemplate, output, table); err != nil {
-		fatalf("Unable to run template: %v", err)
+	if err := runTemplate(generatorInvisible, "../invisible_gen.go", table); err != nil {
+		log.Fatalf("Unable to run template: %v", err)
 	}
 }
 
@@ -59,7 +108,7 @@ func runTemplate(t *template.Template, filename string, data any) error {
 	}
 	bs, err := format.Source(buf.Bytes())
 	if err != nil {
-		verbosef("Bad source:\n%s", buf.String())
+		log.Printf("Bad source:\n%s", buf.String())
 		return fmt.Errorf("unable to format source: %w", err)
 	}
 
@@ -85,37 +134,68 @@ func runTemplate(t *template.Template, filename string, data any) error {
 	return nil
 }
 
-var generatorTemplate = template.Must(template.New("invisibleTemplate").Parse(`// This file is generated by modules/charset/invisible/generate.go DO NOT EDIT
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
+func main() {
+	generateAmbiguous()
+	generateInvisible()
+}
 
+var templateAmbiguous = template.Must(template.New("ambiguousTemplate").Parse(`// This file is generated by modules/charset/generate/generate.go DO NOT EDIT
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
 
 package charset
 
 import "unicode"
 
-var InvisibleRanges = &unicode.RangeTable{
-	R16: []unicode.Range16{
-{{range .R16 }}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
-{{end}}	},
-	R32: []unicode.Range32{
-{{range .R32}}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
-{{end}}	},
-	LatinOffset: {{.LatinOffset}},
+// This file is generated from https://github.com/hediet/vscode-unicode-data/blob/main/out/ambiguous.json
+
+// AmbiguousTable matches a confusable rune with its partner for the Locale
+type AmbiguousTable struct {
+	Confusable []rune
+	With       []rune
+	Locale     string
+	RangeTable *unicode.RangeTable
+}
+
+func newAmbiguousTableMap() map[string]*AmbiguousTable {
+	return map[string]*AmbiguousTable {
+	{{- range .Tables}}
+	{{printf "%q" .Locale}}: {
+			Confusable: []rune{ {{range .Confusable}}{{.}},{{end}} },
+			With: []rune{ {{range .With}}{{.}},{{end}} },
+			Locale: {{printf "%q" .Locale}},
+			RangeTable: &unicode.RangeTable{
+				R16: []unicode.Range16{
+			{{range .RangeTable.R16 }}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
+			{{end}}	},
+				R32: []unicode.Range32{
+			{{range .RangeTable.R32}}		{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
+			{{end}}	},
+				LatinOffset: {{.RangeTable.LatinOffset}},
+			},
+		},
+	{{end}}
+	}
 }
 `))
 
-func logf(format string, args ...any) {
-	fmt.Fprintf(os.Stderr, format+"\n", args...)
-}
+var generatorInvisible = template.Must(template.New("invisibleTemplate").Parse(`// This file is generated by modules/charset/generate/generate.go DO NOT EDIT
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
 
-func verbosef(format string, args ...any) {
-	if verbose {
-		logf(format, args...)
+package charset
+
+import "unicode"
+
+func newInvisibleRangeTable() *unicode.RangeTable {
+	return &unicode.RangeTable{
+		R16: []unicode.Range16{
+{{range .R16 }}			{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
+		{{end}}},
+		R32: []unicode.Range32{
+{{range .R32}}			{Lo:{{.Lo}}, Hi:{{.Hi}}, Stride: {{.Stride}}},
+		{{end}}},
+		LatinOffset: {{.LatinOffset}},
 	}
 }
-
-func fatalf(format string, args ...any) {
-	logf("fatal: "+format+"\n", args...)
-	os.Exit(1)
-}
+`))

modules/charset/htmlstream.go

@@ -1,200 +0,0 @@
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package charset
-
-import (
-	"fmt"
-	"io"
-
-	"golang.org/x/net/html"
-)
-
-// HTMLStreamer represents a SAX-like interface for HTML
-type HTMLStreamer interface {
-	Error(err error) error
-	Doctype(data string) error
-	Comment(data string) error
-	StartTag(data string, attrs ...html.Attribute) error
-	SelfClosingTag(data string, attrs ...html.Attribute) error
-	EndTag(data string) error
-	Text(data string) error
-}
-
-// PassthroughHTMLStreamer is a passthrough streamer
-type PassthroughHTMLStreamer struct {
-	next HTMLStreamer
-}
-
-func NewPassthroughStreamer(next HTMLStreamer) *PassthroughHTMLStreamer {
-	return &PassthroughHTMLStreamer{next: next}
-}
-
-var _ (HTMLStreamer) = &PassthroughHTMLStreamer{}
-
-// Error tells the next streamer in line that there is an error
-func (p *PassthroughHTMLStreamer) Error(err error) error {
-	return p.next.Error(err)
-}
-
-// Doctype tells the next streamer what the doctype is
-func (p *PassthroughHTMLStreamer) Doctype(data string) error {
-	return p.next.Doctype(data)
-}
-
-// Comment tells the next streamer there is a comment
-func (p *PassthroughHTMLStreamer) Comment(data string) error {
-	return p.next.Comment(data)
-}
-
-// StartTag tells the next streamer there is a starting tag
-func (p *PassthroughHTMLStreamer) StartTag(data string, attrs ...html.Attribute) error {
-	return p.next.StartTag(data, attrs...)
-}
-
-// SelfClosingTag tells the next streamer there is a self-closing tag
-func (p *PassthroughHTMLStreamer) SelfClosingTag(data string, attrs ...html.Attribute) error {
-	return p.next.SelfClosingTag(data, attrs...)
-}
-
-// EndTag tells the next streamer there is a end tag
-func (p *PassthroughHTMLStreamer) EndTag(data string) error {
-	return p.next.EndTag(data)
-}
-
-// Text tells the next streamer there is a text
-func (p *PassthroughHTMLStreamer) Text(data string) error {
-	return p.next.Text(data)
-}
-
-// HTMLStreamWriter acts as a writing sink
-type HTMLStreamerWriter struct {
-	io.Writer
-	err error
-}
-
-// Write implements io.Writer
-func (h *HTMLStreamerWriter) Write(data []byte) (int, error) {
-	if h.err != nil {
-		return 0, h.err
-	}
-	return h.Writer.Write(data)
-}
-
-// Write implements io.StringWriter
-func (h *HTMLStreamerWriter) WriteString(data string) (int, error) {
-	if h.err != nil {
-		return 0, h.err
-	}
-	return h.Writer.Write([]byte(data))
-}
-
-// Error tells the next streamer in line that there is an error
-func (h *HTMLStreamerWriter) Error(err error) error {
-	if h.err == nil {
-		h.err = err
-	}
-	return h.err
-}
-
-// Doctype tells the next streamer what the doctype is
-func (h *HTMLStreamerWriter) Doctype(data string) error {
-	_, h.err = h.WriteString("<!DOCTYPE " + data + ">")
-	return h.err
-}
-
-// Comment tells the next streamer there is a comment
-func (h *HTMLStreamerWriter) Comment(data string) error {
-	_, h.err = h.WriteString("<!--" + data + "-->")
-	return h.err
-}
-
-// StartTag tells the next streamer there is a starting tag
-func (h *HTMLStreamerWriter) StartTag(data string, attrs ...html.Attribute) error {
-	return h.startTag(data, attrs, false)
-}
-
-// SelfClosingTag tells the next streamer there is a self-closing tag
-func (h *HTMLStreamerWriter) SelfClosingTag(data string, attrs ...html.Attribute) error {
-	return h.startTag(data, attrs, true)
-}
-
-func (h *HTMLStreamerWriter) startTag(data string, attrs []html.Attribute, selfclosing bool) error {
-	if _, h.err = h.WriteString("<" + data); h.err != nil {
-		return h.err
-	}
-	for _, attr := range attrs {
-		if _, h.err = h.WriteString(" " + attr.Key + "=\"" + html.EscapeString(attr.Val) + "\""); h.err != nil {
-			return h.err
-		}
-	}
-	if selfclosing {
-		if _, h.err = h.WriteString("/>"); h.err != nil {
-			return h.err
-		}
-	} else {
-		if _, h.err = h.WriteString(">"); h.err != nil {
-			return h.err
-		}
-	}
-	return h.err
-}
-
-// EndTag tells the next streamer there is a end tag
-func (h *HTMLStreamerWriter) EndTag(data string) error {
-	_, h.err = h.WriteString("</" + data + ">")
-	return h.err
-}
-
-// Text tells the next streamer there is a text
-func (h *HTMLStreamerWriter) Text(data string) error {
-	_, h.err = h.WriteString(html.EscapeString(data))
-	return h.err
-}
-
-// StreamHTML streams an html to a provided streamer
-func StreamHTML(source io.Reader, streamer HTMLStreamer) error {
-	tokenizer := html.NewTokenizer(source)
-	for {
-		tt := tokenizer.Next()
-		switch tt {
-		case html.ErrorToken:
-			if tokenizer.Err() != io.EOF {
-				return tokenizer.Err()
-			}
-			return nil
-		case html.DoctypeToken:
-			token := tokenizer.Token()
-			if err := streamer.Doctype(token.Data); err != nil {
-				return err
-			}
-		case html.CommentToken:
-			token := tokenizer.Token()
-			if err := streamer.Comment(token.Data); err != nil {
-				return err
-			}
-		case html.StartTagToken:
-			token := tokenizer.Token()
-			if err := streamer.StartTag(token.Data, token.Attr...); err != nil {
-				return err
-			}
-		case html.SelfClosingTagToken:
-			token := tokenizer.Token()
-			if err := streamer.StartTag(token.Data, token.Attr...); err != nil {
-				return err
-			}
-		case html.EndTagToken:
-			token := tokenizer.Token()
-			if err := streamer.EndTag(token.Data); err != nil {
-				return err
-			}
-		case html.TextToken:
-			token := tokenizer.Token()
-			if err := streamer.Text(token.Data); err != nil {
-				return err
-			}
-		default:
-			return fmt.Errorf("unknown type of token: %d", tt)
-		}
-	}
-}

modules/charset/invisible_gen.go

@@ -1,36 +1,38 @@
-// This file is generated by modules/charset/invisible/generate.go DO NOT EDIT
-// Copyright 2022 The Gitea Authors. All rights reserved.
+// This file is generated by modules/charset/generate/generate.go DO NOT EDIT
+// Copyright 2026 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
 package charset
 
 import "unicode"
 
-var InvisibleRanges = &unicode.RangeTable{
-	R16: []unicode.Range16{
-		{Lo: 11, Hi: 13, Stride: 1},
-		{Lo: 127, Hi: 160, Stride: 33},
-		{Lo: 173, Hi: 847, Stride: 674},
-		{Lo: 1564, Hi: 4447, Stride: 2883},
-		{Lo: 4448, Hi: 6068, Stride: 1620},
-		{Lo: 6069, Hi: 6155, Stride: 86},
-		{Lo: 6156, Hi: 6158, Stride: 1},
-		{Lo: 7355, Hi: 7356, Stride: 1},
-		{Lo: 8192, Hi: 8207, Stride: 1},
-		{Lo: 8234, Hi: 8239, Stride: 1},
-		{Lo: 8287, Hi: 8303, Stride: 1},
-		{Lo: 10240, Hi: 12288, Stride: 2048},
-		{Lo: 12644, Hi: 65024, Stride: 52380},
-		{Lo: 65025, Hi: 65039, Stride: 1},
-		{Lo: 65279, Hi: 65440, Stride: 161},
-		{Lo: 65520, Hi: 65528, Stride: 1},
-		{Lo: 65532, Hi: 65532, Stride: 1},
-	},
-	R32: []unicode.Range32{
-		{Lo: 78844, Hi: 119155, Stride: 40311},
-		{Lo: 119156, Hi: 119162, Stride: 1},
-		{Lo: 917504, Hi: 917631, Stride: 1},
-		{Lo: 917760, Hi: 917999, Stride: 1},
-	},
-	LatinOffset: 2,
+func newInvisibleRangeTable() *unicode.RangeTable {
+	return &unicode.RangeTable{
+		R16: []unicode.Range16{
+			{Lo: 11, Hi: 13, Stride: 1},
+			{Lo: 127, Hi: 160, Stride: 33},
+			{Lo: 173, Hi: 847, Stride: 674},
+			{Lo: 1564, Hi: 4447, Stride: 2883},
+			{Lo: 4448, Hi: 6068, Stride: 1620},
+			{Lo: 6069, Hi: 6155, Stride: 86},
+			{Lo: 6156, Hi: 6158, Stride: 1},
+			{Lo: 7355, Hi: 7356, Stride: 1},
+			{Lo: 8192, Hi: 8207, Stride: 1},
+			{Lo: 8234, Hi: 8239, Stride: 1},
+			{Lo: 8287, Hi: 8303, Stride: 1},
+			{Lo: 10240, Hi: 12288, Stride: 2048},
+			{Lo: 12644, Hi: 65024, Stride: 52380},
+			{Lo: 65025, Hi: 65039, Stride: 1},
+			{Lo: 65279, Hi: 65440, Stride: 161},
+			{Lo: 65520, Hi: 65528, Stride: 1},
+			{Lo: 65532, Hi: 65532, Stride: 1},
+		},
+		R32: []unicode.Range32{
+			{Lo: 78844, Hi: 119155, Stride: 40311},
+			{Lo: 119156, Hi: 119162, Stride: 1},
+			{Lo: 917504, Hi: 917631, Stride: 1},
+			{Lo: 917760, Hi: 917999, Stride: 1},
+		},
+		LatinOffset: 2,
+	}
 }

modules/highlight/highlight.go

@@ -6,8 +6,8 @@ package highlight
 
 import (
 	"bytes"
+	gohtml "html"
 	"html/template"
-	"slices"
 	"sync"
 
 	"code.gitea.io/gitea/modules/log"
@@ -15,7 +15,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/alecthomas/chroma/v2"
-	"github.com/alecthomas/chroma/v2/formatters/html"
+	chromahtml "github.com/alecthomas/chroma/v2/formatters/html"
 	"github.com/alecthomas/chroma/v2/styles"
 )
 
@@ -25,8 +25,6 @@ const sizeLimit = 1024 * 1024
 type globalVarsType struct {
 	highlightMapping map[string]string
 	githubStyles     *chroma.Style
-	escapeFull       []template.HTML
-	escCtrlCharsMap  []template.HTML
 }
 
 var (
@@ -42,69 +40,10 @@ func globalVars() *globalVarsType {
 		globalVarsPtr = &globalVarsType{}
 		globalVarsPtr.githubStyles = styles.Get("github")
 		globalVarsPtr.highlightMapping = setting.GetHighlightMapping()
-		globalVarsPtr.escCtrlCharsMap = make([]template.HTML, 256)
-		// ASCII Table 0x00 - 0x1F
-		controlCharNames := []string{
-			"NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
-			"BS", "HT", "LF", "VT", "FF", "CR", "SO", "SI",
-			"DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
-			"CAN", "EM", "SUB", "ESC", "FS", "GS", "RS", "US",
-		}
-		// Uncomment this line if you'd debug the layout without creating a special file, then Space (0x20) will also be escaped.
-		// Don't worry, even if you forget to comment it out and push it to git repo, the CI tests will catch it and fail.
-		// controlCharNames = append(controlCharNames, "SP")
-		for i, s := range controlCharNames {
-			globalVarsPtr.escCtrlCharsMap[i] = template.HTML(`<span class="broken-code-point" data-escaped="` + s + `"><span class="char">` + string(byte(i)) + `</span></span>`)
-		}
-		globalVarsPtr.escCtrlCharsMap[0x7f] = template.HTML(`<span class="broken-code-point" data-escaped="DEL"><span class="char">` + string(byte(0x7f)) + `</span></span>`)
-		globalVarsPtr.escCtrlCharsMap['\t'] = ""
-		globalVarsPtr.escCtrlCharsMap['\n'] = ""
-		globalVarsPtr.escCtrlCharsMap['\r'] = ""
-
-		globalVarsPtr.escapeFull = slices.Clone(globalVarsPtr.escCtrlCharsMap)
-		// exactly the same as Golang's html.EscapeString
-		globalVarsPtr.escapeFull['&'] = "&amp;"
-		globalVarsPtr.escapeFull['\''] = "&#39;"
-		globalVarsPtr.escapeFull['<'] = "&lt;"
-		globalVarsPtr.escapeFull['>'] = "&gt;"
-		globalVarsPtr.escapeFull['"'] = "&#34;"
 	}
 	return globalVarsPtr
 }
 
-func escapeByMap(code []byte, escapeMap []template.HTML) template.HTML {
-	firstEscapePos := -1
-	for i, c := range code {
-		if escapeMap[c] != "" {
-			firstEscapePos = i
-			break
-		}
-	}
-	if firstEscapePos == -1 {
-		return template.HTML(util.UnsafeBytesToString(code))
-	}
-
-	buf := make([]byte, firstEscapePos, len(code)*2)
-	copy(buf[:firstEscapePos], code[:firstEscapePos])
-	for i := firstEscapePos; i < len(code); i++ {
-		c := code[i]
-		if esc := escapeMap[c]; esc != "" {
-			buf = append(buf, esc...)
-		} else {
-			buf = append(buf, c)
-		}
-	}
-	return template.HTML(util.UnsafeBytesToString(buf))
-}
-
-func escapeFullString(code string) template.HTML {
-	return escapeByMap(util.UnsafeStringToBytes(code), globalVars().escapeFull)
-}
-
-func escapeControlChars(code []byte) template.HTML {
-	return escapeByMap(code, globalVars().escCtrlCharsMap)
-}
-
 // UnsafeSplitHighlightedLines splits highlighted code into lines preserving HTML tags
 // It always includes '\n', '\n' can appear at the end of each line or in the middle of HTML tags
 // The '\n' is necessary for copying code from web UI to preserve original code lines
@@ -137,6 +76,10 @@ func UnsafeSplitHighlightedLines(code template.HTML) (ret [][]byte) {
 	}
 }
 
+func htmlEscape(code string) template.HTML {
+	return template.HTML(gohtml.EscapeString(code))
+}
+
 // RenderCodeSlowGuess tries to get a lexer by file name and language first,
 // if not found, it will try to guess the lexer by code content, which is slow (more than several hundreds of milliseconds).
 func RenderCodeSlowGuess(fileName, language, code string) (output template.HTML, lexer chroma.Lexer, lexerDisplayName string) {
@@ -147,7 +90,7 @@ func RenderCodeSlowGuess(fileName, language, code string) (output template.HTML,
 	}
 
 	if len(code) > sizeLimit {
-		return escapeFullString(code), nil, ""
+		return htmlEscape(code), nil, ""
 	}
 
 	lexer = detectChromaLexerWithAnalyze(fileName, language, util.UnsafeStringToBytes(code)) // it is also slow
@@ -156,15 +99,15 @@ func RenderCodeSlowGuess(fileName, language, code string) (output template.HTML,
 
 // RenderCodeByLexer returns a HTML version of code string with chroma syntax highlighting classes
 func RenderCodeByLexer(lexer chroma.Lexer, code string) template.HTML {
-	formatter := html.New(html.WithClasses(true),
-		html.WithLineNumbers(false),
-		html.PreventSurroundingPre(true),
+	formatter := chromahtml.New(chromahtml.WithClasses(true),
+		chromahtml.WithLineNumbers(false),
+		chromahtml.PreventSurroundingPre(true),
 	)
 
 	iterator, err := lexer.Tokenise(nil, code)
 	if err != nil {
 		log.Error("Can't tokenize code: %v", err)
-		return escapeFullString(code)
+		return htmlEscape(code)
 	}
 
 	htmlBuf := &bytes.Buffer{}
@@ -172,14 +115,9 @@ func RenderCodeByLexer(lexer chroma.Lexer, code string) template.HTML {
 	err = formatter.Format(htmlBuf, globalVars().githubStyles, iterator)
 	if err != nil {
 		log.Error("Can't format code: %v", err)
-		return escapeFullString(code)
+		return htmlEscape(code)
 	}
-
-	// At the moment, we do not escape control chars here (unlike RenderFullFile which escapes control chars).
-	// The reason is: it is a very rare case that a text file contains control chars.
-	// This function is usually used by highlight diff and blame, not quite sure whether there will be side effects.
-	// If there would be new user feedback about this, we can re-consider about various edge cases.
-	return template.HTML(htmlBuf.String())
+	return template.HTML(util.UnsafeBytesToString(htmlBuf.Bytes()))
 }
 
 // RenderFullFile returns a slice of chroma syntax highlighted HTML lines of code and the matched lexer name
@@ -191,10 +129,9 @@ func RenderFullFile(fileName, language string, code []byte) ([]template.HTML, st
 	lexerName := formatLexerName(lexer.Config().Name)
 	rendered := RenderCodeByLexer(lexer, util.UnsafeBytesToString(code))
 	unsafeLines := UnsafeSplitHighlightedLines(rendered)
-	lines := make([]template.HTML, 0, len(unsafeLines))
-	for _, lineBytes := range unsafeLines {
-		line := escapeControlChars(lineBytes)
-		lines = append(lines, line)
+	lines := make([]template.HTML, len(unsafeLines))
+	for idx, lineBytes := range unsafeLines {
+		lines[idx] = template.HTML(util.UnsafeBytesToString(lineBytes))
 	}
 	return lines, lexerName
 }
@@ -213,7 +150,7 @@ func renderPlainText(code []byte) []template.HTML {
 			content = code[pos : pos+nextPos+1]
 			pos += nextPos + 1
 		}
-		lines = append(lines, escapeFullString(util.UnsafeBytesToString(content)))
+		lines = append(lines, htmlEscape(util.UnsafeBytesToString(content)))
 	}
 	return lines
 }

modules/highlight/highlight_test.go

@@ -204,14 +204,3 @@ func TestUnsafeSplitHighlightedLines(t *testing.T) {
 	assert.Equal(t, "<span>a</span>\n", string(ret[0]))
 	assert.Equal(t, "<span>b\n</span>", string(ret[1]))
 }
-
-func TestEscape(t *testing.T) {
-	assert.Equal(t, template.HTML("\t\r\n<span class=\"broken-code-point\" data-escaped=\"NUL\"><span class=\"char\">\x00</span></span><span class=\"broken-code-point\" data-escaped=\"US\"><span class=\"char\">\x1f</span></span>&'\"<>"), escapeControlChars([]byte("\t\r\n\x00\x1f&'\"<>")))
-	assert.Equal(t, template.HTML("<span class=\"broken-code-point\" data-escaped=\"NUL\"><span class=\"char\">\x00</span></span><span class=\"broken-code-point\" data-escaped=\"US\"><span class=\"char\">\x1f</span></span>&amp;&#39;&#34;&lt;&gt;\t\r\n"), escapeFullString("\x00\x1f&'\"<>\t\r\n"))
-
-	out, _ := RenderFullFile("a.py", "", []byte("# \x7f<>"))
-	assert.Equal(t, template.HTML(`<span class="c1"># <span class="broken-code-point" data-escaped="DEL"><span class="char">`+string(byte(0x7f))+`</span></span>&lt;&gt;</span>`), out[0])
-
-	out = renderPlainText([]byte("# \x7f<>"))
-	assert.Equal(t, template.HTML(`# <span class="broken-code-point" data-escaped="DEL"><span class="char">`+string(byte(0x7f))+`</span></span>&lt;&gt;`), out[0])
-}

modules/indexer/code/search.go

@@ -74,7 +74,7 @@ func HighlightSearchResultCode(filename, language string, lineNums []int, code s
 	// we should highlight the whole code block first, otherwise it doesn't work well with multiple line highlighting
 	lexer := highlight.DetectChromaLexerByFileName(filename, language)
 	hl := highlight.RenderCodeByLexer(lexer, code)
-	highlightedLines := strings.Split(string(hl), "\n")
+	highlightedLines := highlight.UnsafeSplitHighlightedLines(hl)
 
 	// The lineNums outputted by render might not match the original lineNums, because "highlight" removes the last `\n`
 	lines := make([]*ResultLine, min(len(highlightedLines), len(lineNums)))

modules/templates/util_render.go

@@ -16,6 +16,7 @@ import (
 	issues_model "code.gitea.io/gitea/models/issues"
 	"code.gitea.io/gitea/models/renderhelper"
 	"code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/emoji"
 	"code.gitea.io/gitea/modules/htmlutil"
 	"code.gitea.io/gitea/modules/log"
@@ -277,3 +278,24 @@ func (ut *RenderUtils) RenderThemeItem(info *webtheme.ThemeMetaInfo, iconSize in
 	extraIcon := svg.RenderHTML(info.GetExtraIconName(), iconSize)
 	return htmlutil.HTMLFormat(`<div class="theme-menu-item" data-tooltip-content="%s">%s %s %s</div>`, info.GetDescription(), icon, info.DisplayName, extraIcon)
 }
+
+func (ut *RenderUtils) RenderUnicodeEscapeToggleButton(escapeStatus *charset.EscapeStatus) template.HTML {
+	if escapeStatus == nil || !escapeStatus.Escaped {
+		return ""
+	}
+	locale := ut.ctx.Value(translation.ContextKey).(translation.Locale)
+	var title template.HTML
+	if escapeStatus.HasAmbiguous {
+		title += locale.Tr("repo.ambiguous_runes_line")
+	} else if escapeStatus.HasInvisible {
+		title += locale.Tr("repo.invisible_runes_line")
+	}
+	return htmlutil.HTMLFormat(`<button type="button" class="toggle-escape-button btn interact-bg" title="%s"></button>`, title)
+}
+
+func (ut *RenderUtils) RenderUnicodeEscapeToggleTd(combined, escapeStatus *charset.EscapeStatus) template.HTML {
+	if combined == nil || !combined.Escaped {
+		return ""
+	}
+	return `<td class="lines-escape">` + ut.RenderUnicodeEscapeToggleButton(escapeStatus) + `</td>`
+}

options/locale/locale_en-US.json

@@ -1216,7 +1216,7 @@
   "repo.ambiguous_runes_description": "This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.",
   "repo.invisible_runes_line": "This line has invisible unicode characters",
   "repo.ambiguous_runes_line": "This line has ambiguous unicode characters",
-  "repo.ambiguous_character": "%[1]c [U+%04[1]X] can be confused with %[2]c [U+%04[2]X]",
+  "repo.ambiguous_character": "%[1]s can be confused with %[2]s",
   "repo.escape_control_characters": "Escape",
   "repo.unescape_control_characters": "Unescape",
   "repo.file_copy_permalink": "Copy Permalink",

routers/web/devtest/devtest.go

@@ -17,7 +17,9 @@ import (
 	"code.gitea.io/gitea/models/db"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/badge"
+	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/indexer/code"
 	"code.gitea.io/gitea/modules/templates"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/context"
@@ -190,9 +192,33 @@ func prepareMockData(ctx *context.Context) {
 		prepareMockDataBadgeActionsSvg(ctx)
 	case "/devtest/relative-time":
 		prepareMockDataRelativeTime(ctx)
+	case "/devtest/unicode-escape":
+		prepareMockDataUnicodeEscape(ctx)
 	}
 }
 
+func prepareMockDataUnicodeEscape(ctx *context.Context) {
+	content := "// demo code\n"
+	content += "if accessLevel != \"user\u202E \u2066// Check if admin (invisible char)\u2069 \u2066\" { }\n"
+	content += "if O𝐾 { } // ambiguous char\n"
+	content += "if O𝐾 && accessLevel != \"user\u202E \u2066// ambiguous char + invisible char\u2069 \u2066\" { }\n"
+	content += "str := `\xef` // broken char\n"
+	content += "str := `\x00 \x19 \x7f` // control char\n"
+
+	lineNums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
+
+	highlightLines := code.HighlightSearchResultCode("demo.go", "", lineNums, content)
+	escapeStatus := &charset.EscapeStatus{}
+	lineEscapeStatus := make([]*charset.EscapeStatus, len(highlightLines))
+	for i, hl := range highlightLines {
+		lineEscapeStatus[i], hl.FormattedContent = charset.EscapeControlHTML(hl.FormattedContent, ctx.Locale)
+		escapeStatus = escapeStatus.Or(lineEscapeStatus[i])
+	}
+	ctx.Data["HighlightLines"] = highlightLines
+	ctx.Data["EscapeStatus"] = escapeStatus
+	ctx.Data["LineEscapeStatus"] = lineEscapeStatus
+}
+
 func TmplCommon(ctx *context.Context) {
 	prepareMockData(ctx)
 	if ctx.Req.Method == http.MethodPost {

routers/web/repo/view.go

@@ -159,7 +159,7 @@ func markupRenderToHTML(ctx *context.Context, renderCtx *markup.RenderContext, r
 	go func() {
 		sb := &strings.Builder{}
 		if markup.RendererNeedPostProcess(renderer) {
-			escaped, _ = charset.EscapeControlReader(markupRd, sb, ctx.Locale, charset.RuneNBSP) // We allow NBSP here this is rendered
+			escaped, _ = charset.EscapeControlReader(markupRd, sb, ctx.Locale, charset.EscapeOptionsForView())
 		} else {
 			escaped = &charset.EscapeStatus{}
 			_, _ = io.Copy(sb, markupRd)

routers/web/repo/wiki.go

@@ -258,8 +258,7 @@ func renderViewPage(ctx *context.Context) (*git.Repository, *git.TreeEntry) {
 		defer markupWr.Close()
 		done := make(chan struct{})
 		go func() {
-			// We allow NBSP here this is rendered
-			escaped, _ = charset.EscapeControlReader(markupRd, buf, ctx.Locale, charset.RuneNBSP)
+			escaped, _ = charset.EscapeControlReader(markupRd, buf, ctx.Locale, charset.EscapeOptionsForView())
 			output = template.HTML(buf.String())
 			buf.Reset()
 			close(done)

services/markup/renderhelper_codepreview.go

@@ -101,7 +101,7 @@ func renderRepoFileCodePreview(ctx context.Context, opts markup.RenderCodePrevie
 	escapeStatus := &charset.EscapeStatus{}
 	lineEscapeStatus := make([]*charset.EscapeStatus, len(highlightLines))
 	for i, hl := range highlightLines {
-		lineEscapeStatus[i], hl.FormattedContent = charset.EscapeControlHTML(hl.FormattedContent, webCtx.Base.Locale, charset.RuneNBSP)
+		lineEscapeStatus[i], hl.FormattedContent = charset.EscapeControlHTML(hl.FormattedContent, webCtx.Base.Locale, charset.EscapeOptionsForView())
 		escapeStatus = escapeStatus.Or(lineEscapeStatus[i])
 	}
 

services/markup/renderhelper_codepreview_test.go

@@ -37,10 +37,12 @@ func TestRenderHelperCodePreview(t *testing.T) {
 	<table class="file-view">
 		<tbody><tr>
 				<td class="lines-num"><span data-line-number="1"></span></td>
-				<td class="lines-code chroma"><div class="code-inner"><span class="gh"># repo1</div></td>
+				<td class="lines-code chroma"><div class="code-inner"><span class="gh"># repo1
+</span></div></td>
 			</tr><tr>
 				<td class="lines-num"><span data-line-number="2"></span></td>
-				<td class="lines-code chroma"><div class="code-inner"></span></div></td>
+				<td class="lines-code chroma"><div class="code-inner">
+</div></td>
 			</tr></tbody>
 	</table>
 </div>
@@ -64,7 +66,8 @@ func TestRenderHelperCodePreview(t *testing.T) {
 	<table class="file-view">
 		<tbody><tr>
 				<td class="lines-num"><span data-line-number="1"></span></td>
-				<td class="lines-code chroma"><div class="code-inner"><span class="gh"># repo1</div></td>
+				<td class="lines-code chroma"><div class="code-inner"><span class="gh"># repo1
+</span></div></td>
 			</tr></tbody>
 	</table>
 </div>

templates/base/markup_codepreview.tmpl

@@ -13,10 +13,7 @@
 			{{- range $idx, $line := .HighlightLines -}}
 			<tr>
 				<td class="lines-num"><span data-line-number="{{$line.Num}}"></span></td>
-				{{- if $.EscapeStatus.Escaped -}}
-					{{- $lineEscapeStatus := index $.LineEscapeStatus $idx -}}
-					<td class="lines-escape">{{if $lineEscapeStatus.Escaped}}<a href="#" class="toggle-escape-button btn interact-bg" title="{{if $lineEscapeStatus.HasInvisible}}{{ctx.Locale.Tr "repo.invisible_runes_line"}} {{end}}{{if $lineEscapeStatus.HasAmbiguous}}{{ctx.Locale.Tr "repo.ambiguous_runes_line"}}{{end}}"></a>{{end}}</td>
-				{{- end}}
+				{{- ctx.RenderUtils.RenderUnicodeEscapeToggleTd $.EscapeStatus (index $.LineEscapeStatus $idx)}}
 				<td class="lines-code chroma"><div class="code-inner">{{$line.FormattedContent}}</div></td>{{/* only div works, span generates incorrect HTML structure */}}
 			</tr>
 			{{- end -}}

templates/devtest/unicode-escape.tmpl

@@ -0,0 +1,17 @@
+{{template "devtest/devtest-header"}}
+<div class="page-content repository">
+	<div class="file-content">
+		<table class="file-view unicode-escaped">
+			<tbody>
+			{{range $idx, $line := .HighlightLines}}
+			<tr>
+				<td class="lines-num"><span data-line-number="{{$line.Num}}"></span></td>
+				{{ctx.RenderUtils.RenderUnicodeEscapeToggleTd $.EscapeStatus (index $.LineEscapeStatus $idx)}}
+				<td class="lines-code chroma"><div class="code-inner">{{$line.FormattedContent}}</div></td>
+			</tr>
+			{{end}}
+			</tbody>
+		</table>
+	</div>
+</div>
+{{template "devtest/devtest-footer"}}

templates/repo/blame.tmpl

@@ -66,13 +66,9 @@
 							<td class="lines-num">
 								<span id="L{{$row.RowNumber}}" data-line-number="{{$row.RowNumber}}"></span>
 							</td>
-							{{if $.EscapeStatus.Escaped}}
-								<td class="lines-escape">
-									{{if $row.EscapeStatus.Escaped}}
-										<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $row}}"></button>
-									{{end}}
-								</td>
-							{{end}}
+
+							{{ctx.RenderUtils.RenderUnicodeEscapeToggleTd $.EscapeStatus $row.EscapeStatus}}
+
 							<td rel="L{{$row.RowNumber}}" class="lines-code blame-code chroma">
 								<code class="code-inner tw-pl-2">{{$row.Code}}</code>
 							</td>

templates/repo/diff/blob_excerpt.tmpl

@@ -12,7 +12,7 @@
 		{{else}}
 			{{$inlineDiff := $.section.GetComputedInlineDiffFor $line ctx.Locale}}
 			<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$.FileNameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
-			<td class="lines-escape lines-escape-old">{{if and $line.LeftIdx $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
+			<td class="lines-escape lines-escape-old">{{if $line.LeftIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}{{end}}</td>
 			<td class="lines-type-marker lines-type-marker-old">{{if $line.LeftIdx}}<span class="tw-font-mono" data-type-marker=""></span>{{end}}</td>
 			<td class="lines-code lines-code-old">
 				{{/* ATTENTION: BLOB-EXCERPT-COMMENT-RIGHT: here it intentionally use "right" side to comment, because the backend code depends on the assumption that the comment only happens on right side*/}}
@@ -28,7 +28,7 @@
 				{{- end -}}
 			</td>
 			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
-			<td class="lines-escape lines-escape-new">{{if and $line.RightIdx $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
+			<td class="lines-escape lines-escape-new">{{if and $line.RightIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}{{end}}</td>
 			<td class="lines-type-marker lines-type-marker-new">{{if $line.RightIdx}}<span class="tw-font-mono" data-type-marker=""></span>{{end}}</td>
 			<td class="lines-code lines-code-new">
 				{{- if and $canCreateComment $line.RightIdx -}}
@@ -69,7 +69,7 @@
 			<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$.FileNameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
 		{{end}}
 		{{$inlineDiff := $.section.GetComputedInlineDiffFor $line ctx.Locale}}
-		<td class="lines-escape">{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
+		<td class="lines-escape">{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}</td>
 		<td class="lines-type-marker"><span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span></td>
 		<td class="lines-code{{if (not $line.RightIdx)}} lines-code-old{{end}}">
 			{{- if and $canCreateComment -}}
@@ -77,7 +77,7 @@
 					{{- svg "octicon-plus" -}}
 				</button>
 			{{- end -}}
-			<code {{if $inlineDiff.EscapeStatus.Escaped}}class="code-inner has-escaped" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"{{else}}class="code-inner"{{end}}>{{$inlineDiff.Content}}</code>
+			<code class="code-inner {{if $inlineDiff.EscapeStatus.Escaped}}has-escaped{{end}}">{{$inlineDiff.Content}}</code>
 		</td>
 	</tr>
 	{{if $line.Comments}}

templates/repo/diff/escape_title.tmpl

@@ -1,2 +0,0 @@
-{{if .diff.EscapeStatus.HasInvisible}}{{ctx.Locale.Tr "repo.invisible_runes_line"}} {{end -}}
-{{- if .diff.EscapeStatus.HasAmbiguous}}{{ctx.Locale.Tr "repo.ambiguous_runes_line"}}{{end}}

templates/repo/diff/section_code.tmpl

@@ -1 +1 @@
-<code class="code-inner{{if .diff.EscapeStatus.Escaped}} has-escaped{{end}}"{{if .diff.EscapeStatus.Escaped}} title="{{template "repo/diff/escape_title" .}}"{{end}}>{{.diff.Content}}</code>
+<code class="code-inner{{if .diff.EscapeStatus.Escaped}} has-escaped{{end}}">{{.diff.Content}}</code>

templates/repo/diff/section_split.tmpl

@@ -18,14 +18,14 @@
 				{{if eq .GetType 4}}
 					{{$inlineDiff := $section.GetComputedInlineDiffFor $line ctx.Locale}}
 					<td class="lines-num lines-num-old">{{$line.RenderBlobExcerptButtons $file.NameHash $diffBlobExcerptData}}</td>
-					<td class="lines-escape lines-escape-old">{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}</td>
+					<td class="lines-escape lines-escape-old">{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}</td>
 					<td colspan="6" class="lines-code lines-code-old">{{template "repo/diff/section_code" dict "diff" $inlineDiff}}</td>
 				{{else if and (eq .GetType 3) $hasmatch}}{{/* DEL */}}
 					{{$match := index $section.Lines $line.Match}}
 					{{- $leftDiff := ""}}{{if $line.LeftIdx}}{{$leftDiff = $section.GetComputedInlineDiffFor $line ctx.Locale}}{{end}}
 					{{- $rightDiff := ""}}{{if $match.RightIdx}}{{$rightDiff = $section.GetComputedInlineDiffFor $match ctx.Locale}}{{end}}
 					<td class="lines-num lines-num-old del-code" data-line-num="{{$line.LeftIdx}}"><span rel="diff-{{$file.NameHash}}L{{$line.LeftIdx}}"></span></td>
-					<td class="lines-escape del-code lines-escape-old">{{if $line.LeftIdx}}{{if $leftDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $leftDiff}}"></button>{{end}}{{end}}</td>
+					<td class="lines-escape del-code lines-escape-old">{{if $line.LeftIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $leftDiff.EscapeStatus}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-old del-code"><span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span></td>
 					<td class="lines-code lines-code-old del-code">
 						{{- if and $.root.SignedUserID $.root.PageIsPullFiles -}}
@@ -40,7 +40,7 @@
 						{{- end -}}
 					</td>
 					<td class="lines-num lines-num-new add-code" data-line-num="{{if $match.RightIdx}}{{$match.RightIdx}}{{end}}"><span rel="{{if $match.RightIdx}}diff-{{$file.NameHash}}R{{$match.RightIdx}}{{end}}"></span></td>
-					<td class="lines-escape add-code lines-escape-new">{{if $match.RightIdx}}{{if $rightDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $rightDiff}}"></button>{{end}}{{end}}</td>
+					<td class="lines-escape add-code lines-escape-new">{{if $match.RightIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $rightDiff.EscapeStatus}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-new add-code">{{if $match.RightIdx}}<span class="tw-font-mono" data-type-marker="{{$match.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-new add-code">
 						{{- if and $.root.SignedUserID $.root.PageIsPullFiles -}}
@@ -57,7 +57,7 @@
 				{{else}}
 					{{$inlineDiff := $section.GetComputedInlineDiffFor $line ctx.Locale}}
 					<td class="lines-num lines-num-old" data-line-num="{{if $line.LeftIdx}}{{$line.LeftIdx}}{{end}}"><span rel="{{if $line.LeftIdx}}diff-{{$file.NameHash}}L{{$line.LeftIdx}}{{end}}"></span></td>
-					<td class="lines-escape lines-escape-old">{{if $line.LeftIdx}}{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}{{end}}</td>
+					<td class="lines-escape lines-escape-old">{{if $line.LeftIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-old">{{if $line.LeftIdx}}<span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-old">
 						{{- if and $.root.SignedUserID $.root.PageIsPullFiles (not (eq .GetType 2)) -}}
@@ -72,7 +72,7 @@
 						{{- end -}}
 					</td>
 					<td class="lines-num lines-num-new" data-line-num="{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}"><span rel="{{if $line.RightIdx}}diff-{{$file.NameHash}}R{{$line.RightIdx}}{{end}}"></span></td>
-					<td class="lines-escape lines-escape-new">{{if $line.RightIdx}}{{if $inlineDiff.EscapeStatus.Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>{{end}}{{end}}</td>
+					<td class="lines-escape lines-escape-new">{{if $line.RightIdx}}{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}{{end}}</td>
 					<td class="lines-type-marker lines-type-marker-new">{{if $line.RightIdx}}<span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span>{{end}}</td>
 					<td class="lines-code lines-code-new">
 						{{- if and $.root.SignedUserID $.root.PageIsPullFiles (not (eq .GetType 3)) -}}

templates/repo/diff/section_unified.tmpl

@@ -24,9 +24,7 @@
 			{{end}}
 			{{$inlineDiff := $section.GetComputedInlineDiffFor $line ctx.Locale -}}
 			<td class="lines-escape">
-				{{- if $inlineDiff.EscapeStatus.Escaped -}}
-					<button class="toggle-escape-button btn interact-bg" title="{{template "repo/diff/escape_title" dict "diff" $inlineDiff}}"></button>
-				{{- end -}}
+				{{ctx.RenderUtils.RenderUnicodeEscapeToggleButton $inlineDiff.EscapeStatus}}
 			</td>
 			<td class="lines-type-marker"><span class="tw-font-mono" data-type-marker="{{$line.GetLineTypeMarker}}"></span></td>
 			{{if eq .GetType 4}}

templates/repo/view_file.tmpl

@@ -109,9 +109,7 @@
 						{{$line := Eval $idx "+" 1}}
 						<tr>
 							<td class="lines-num"><span id="L{{$line}}" data-line-number="{{$line}}"></span></td>
-							{{if $.EscapeStatus.Escaped}}
-								<td class="lines-escape">{{if (index $.LineEscapeStatus $idx).Escaped}}<button class="toggle-escape-button btn interact-bg" title="{{if (index $.LineEscapeStatus $idx).HasInvisible}}{{ctx.Locale.Tr "repo.invisible_runes_line"}} {{end}}{{if (index $.LineEscapeStatus $idx).HasAmbiguous}}{{ctx.Locale.Tr "repo.ambiguous_runes_line"}}{{end}}"></button>{{end}}</td>
-							{{end}}
+							{{ctx.RenderUtils.RenderUnicodeEscapeToggleTd $.EscapeStatus (index $.LineEscapeStatus $idx)}}
 							<td rel="L{{$line}}" class="lines-code chroma"><code class="code-inner">{{$code}}</code></td>
 						</tr>
 					{{end}}

web_src/css/base.css

@@ -17,6 +17,7 @@
   /* images */
   --checkbox-mask-checked: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="12" height="9" viewBox="0 0 12 9"><path fill-rule="evenodd" d="M11.78.22a.75.75 0 0 1 0 1.061L4.52 8.541a.75.75 0 0 1-1.062 0L.202 5.285a.75.75 0 0 1 1.061-1.061l2.725 2.723L10.718.22a.75.75 0 0 1 1.062 0"/></svg>');
   --checkbox-mask-indeterminate: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="10" height="2" viewBox="0 0 10 2"><path fill-rule="evenodd" d="M0 1a1 1 0 0 1 1-1h8a1 1 0 1 1 0 2H1a1 1 0 0 1-1-1" clip-rule="evenodd"/></svg>');
+  --octicon-alert-fill: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575ZM8 5a.75.75 0 0 0-.75.75v2.5a.75.75 0 0 0 1.5 0v-2.5A.75.75 0 0 0 8 5Zm1 6a1 1 0 1 0-2 0 1 1 0 0 0 2 0Z"/></svg>');
   --octicon-chevron-right: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="M6.22 3.22a.75.75 0 0 1 1.06 0l4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L9.94 8 6.22 4.28a.75.75 0 0 1 0-1.06Z"></path></svg>');
   --octicon-x: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.75.75 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.75.75 0 0 1-.734-.215L8 9.06l-3.22 3.22a.75.75 0 0 1-1.042-.018.75.75 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06"/></svg>');
   --select-arrows: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="16" height="16"><path d="m4.074 9.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.043 9H4.251a.25.25 0 0 0-.177.427m0-1.957L7.47 4.073a.25.25 0 0 1 .354 0L11.22 7.47a.25.25 0 0 1-.177.426H4.251a.25.25 0 0 1-.177-.426"/></svg>');
@@ -686,6 +687,7 @@ overflow-menu .ui.label {
 }
 
 .lines-num,
+.lines-escape,
 .lines-code {
   font-size: 12px;
   font-family: var(--fonts-monospace);

web_src/css/modules/charescape.css

@@ -1,24 +1,31 @@
 /*
 Show the escaped and hide the real char:
-  <span class="broken-code-point" data-escaped="DEL"><span class="char">{real-char}</span></span>
+  <span class="broken-code-point" data-escaped="␡"><span class="char">{real-char}</span></span>
 Only show the real-char:
   <span class="broken-code-point">{real-char}</span>
 */
-.broken-code-point:not([data-escaped]),
-.broken-code-point[data-escaped]::before {
+.broken-code-point:not([data-escaped]) {
   border-radius: 4px;
   padding: 0 2px;
-  color: var(--color-body);
-  background: var(--color-text-light-1);
+  border: 1px var(--color-yellow) solid;
+}
+
+.broken-code-point[data-escaped] {
+  position: relative;
 }
 
 .broken-code-point[data-escaped]::before {
   visibility: visible;
   content: attr(data-escaped);
+  border-radius: 2px;
+  padding: 0 1px;
+  border: 1px var(--color-yellow) solid;
 }
+
 .broken-code-point[data-escaped] .char {
-  /* make it copyable by selecting the text (AI suggestion, no other solution) */
+  /* keep the original character selectable/copyable while showing the escaped label via ::before */
   position: absolute;
+  left: 0;
   opacity: 0;
   pointer-events: none;
 }
@@ -26,11 +33,11 @@ Only show the real-char:
 /*
 Show the escaped and hide the real-char:
   <span class="unicode-escaped">
-    <span class="escaped-code-point" data-escaped="U+1F600"><span class="char">{real-char}</span></span>
+    <span class="escaped-code-point" data-escaped="[U+1F600]"><span class="char">{real-char}</span></span>
   </span>
 Hide the escaped and show the real-char:
   <span>
-    <span class="escaped-code-point" data-escaped="U+1F600"><span class="char">{real-char}</span></span>
+    <span class="escaped-code-point" data-escaped="[U+1F600]"><span class="char">{real-char}</span></span>
   </span>
 */
 .unicode-escaped .escaped-code-point[data-escaped]::before {

web_src/css/review.css

@@ -15,11 +15,20 @@
   transform: scale(1.1);
 }
 
+.lines-escape .toggle-escape-button {
+  margin: -1px 2px 0;
+}
+
 .lines-escape .toggle-escape-button::before {
-  visibility: visible;
-  content: "⚠️";
-  font-family: var(--fonts-emoji);
-  color: var(--color-red);
+  content: "";
+  display: inline-flex;
+  width: 14px;
+  height: 14px;
+  background-color: var(--color-yellow); /* TODO: maybe it needs a new kind of color, there is no suitable "warning" color in the current palette */
+  mask-image: var(--octicon-alert-fill);
+  -webkit-mask-image: var(--octicon-alert-fill);
+  mask-size: contain;
+  -webkit-mask-size: contain;
 }
 
 .repository .diff-file-box .code-diff td.lines-escape {