Fix bracket matching

This fixes golang/go/issues/#72089

Author: pgundlach

unicode/bidi/bidi.go

@@ -109,17 +109,17 @@ func (p *Paragraph) prepareInput() (n int, err error) {
 			return bytecount, nil
 		}
 		p.types = append(p.types, cls)
-		if props.IsOpeningBracket() {
+
+		switch {
+		case !props.IsBracket():
+			p.pairTypes = append(p.pairTypes, bpNone)
+			p.pairValues = append(p.pairValues, 0)
+		case props.IsOpeningBracket():
 			p.pairTypes = append(p.pairTypes, bpOpen)
 			p.pairValues = append(p.pairValues, r)
-		} else if props.IsBracket() {
-			// this must be a closing bracket,
-			// since IsOpeningBracket is not true
+		default:
 			p.pairTypes = append(p.pairTypes, bpClose)
-			p.pairValues = append(p.pairValues, r)
-		} else {
-			p.pairTypes = append(p.pairTypes, bpNone)
-			p.pairValues = append(p.pairValues, 0)
+			p.pairValues = append(p.pairValues, props.reverseBracket(r))
 		}
 	}
 	return bytecount, nil

unicode/bidi/bidi_test.go

@@ -345,3 +345,35 @@ func TestAppendReverse(t *testing.T) {
 	}
 
 }
+
+func TestBracket(t *testing.T) {
+	str := `ع a (b)`
+	p := Paragraph{}
+	p.SetString(str, DefaultDirection(LeftToRight))
+	order, err := p.Order()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	expectedRuns := []runInformation{
+		{"ع ", RightToLeft, 0, 1},
+		{"a (b)", LeftToRight, 2, 6},
+	}
+
+	if nr, want := order.NumRuns(), len(expectedRuns); nr != want {
+		t.Errorf("order.NumRuns() = %d; want %d", nr, want)
+	}
+
+	for i, want := range expectedRuns {
+		r := order.Run(i)
+		if got := r.String(); got != want.str {
+			t.Errorf("Run(%d) = %q; want %q", i, got, want.str)
+		}
+		if s, e := r.Pos(); s != want.start || e != want.end {
+			t.Errorf("Run(%d).start = %d, .end = %d; want start = %d, end = %d", i, s, e, want.start, want.end)
+		}
+		if d := r.Direction(); d != want.dir {
+			t.Errorf("Run(%d).Direction = %d; want %d", i, d, want.dir)
+		}
+	}
+}