}
		}
		// different end alignments
		b1 = b[:i]
		for j := 0; j < len(b1); j++ {
			b1[j] = 'x'
			pos := IndexByte(b1, 'x')
			if pos != j {
				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
			}
			b1[j] = 0
			pos = IndexByte(b1, 'x')
			if pos != -1 {
				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
			}
		}
		// different start and end alignments
		b1 = b[i/2 : n-(i+1)/2]

			repl := " " + gofmtPos(expr, old.Pos())
			end := fset.Position(old.End())
			// Subtract 1 from the column if we are going to
			// append a close parenthesis. That will set the
			// correct column for the following characters.
			sub := 0
			if r.Name.Kind != "type" {
				sub = 1
			}
			if end.Column > sub {
				repl = fmt.Sprintf("%s /*line :%d:%d*/", repl, end.Line, end.Column-sub)
			}

		return
	}
	got, err := io.ReadAll(rw)
	if err != nil {
		t.Errorf("%v: OpenRaw ReadAll error=%v", f.Name, err)
		return
	}
	end := uint64(start) + f.CompressedSize64
	want := raw[start:end]
	if !bytes.Equal(got, want) {
		t.Logf("got %q", got)
		t.Logf("want %q", want)
		t.Errorf("%v: OpenRaw returned unexpected bytes", f.Name)
		return
	}

	r, err := f.Open()

			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            26,
			want:         26,
			wantBuffered: 0,
		},
		{
			name:         "discard more than end",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            27,
			want:         26,
			wantErr:      io.EOF,
			wantBuffered: 0,
		},