Text rendering error​

[jingjiangxiaojian]

Describe the bug
An error occurs when my PDF content contains the following text.
Bad state: No element
[GETX] Error: _StackTrace #0 Iterable.first (dart:core/iterable.dart:663:7)
#1 TtfWriter.withChars (package:pdf/src/pdf/font/ttf_writer.dart:112:67)
#2 PdfTtfFont._buildType0 (package:pdf/src/pdf/obj/ttffont.dart:121:28)
#3 PdfTtfFont.prepare (package:pdf/src/pdf/obj/ttffont.dart:162:7)
#4 PdfDocument._write (package:pdf/src/pdf/document.dart:227:10)
#5 PdfDocument.save. (package:pdf/src/pdf/document.dart:261:13)
#6 _RemoteRunner._run (dart:isolate:1116:47)
#7 _RemoteRunner._remoteExecute (dart:isolate:1110:12)
#8 _delayEntrypointInvocation. (dart:isolate-patch/isolate_patch.dart:317:17)
#9 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:193:12)
To Reproduce
Code snippet to reproduce the behavior:

/*
 * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'dart:async';
import 'dart:math';
import 'dart:typed_data';

import 'package:flutter/services.dart' show rootBundle;
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:printing/printing.dart';

import '../data.dart';

const PdfColor green = PdfColor.fromInt(0xff9ce5d0);
const PdfColor lightGreen = PdfColor.fromInt(0xffcdf1e7);
const sep = 120.0;


List<pw.Partitions> testUI(pw.Context context, pw.PageTheme pageTheme,
    pw.MemoryImage profileImage) {
  return [
    pw.Partitions(
      children: [
        pw.Partition(
          child: pw.Column(
            crossAxisAlignment: pw.CrossAxisAlignment.start,
            children: <pw.Widget>[
              pw.Container(
                padding: const pw.EdgeInsets.only(left: 30, bottom: 20),
                child: pw.Column(
                  crossAxisAlignment: pw.CrossAxisAlignment.start,
                  children: <pw.Widget>[
                    pw.Text(
                      '想⻜的乌⻳从前，有⼀只乌⻳。⼀天，乌⻳听⻅⼀群小⻦在喊：“我们走吧！我们快走吧！”乌⻳问：“你们要去哪⼉？”小⻦说：“我们要去⼀个很美丽的地⽅。”乌⻳问：“我能和你们⼀起去吗？”小⻦说：“可你不会⻜啊！”乌⻳很伤⼼。小⻦想出了⼀个办法。他们让乌⻳叼着⼀根棍⼦，两只小⻦叼着棍⼦的两端。于是，小⻦带着乌⻳⻜起来了。乌⻳很⾼兴，他喜欢⻜的感觉。小⻦越⻜越⾼，⽩云在乌⻳⾝边飘着，⻛从他耳边吹过。下⾯是绿⾊的⽥野，蓝⾊的小河，地上的房⼦都变得很小很小。乌⻳开⼼极了，忍不住喊起来：“太美了！啊——”乌⻳从天上掉下来了！他重重地掉在地上，光滑的壳上摔出了好多裂（li）纹。从此以后，乌⻳的壳就成',
                    ),
                    pw.Padding(padding: const pw.EdgeInsets.only(top: 20)),
                    pw.Text(
                      'annotation',
                      style: pw.TextStyle(
                        fontSize: 32,
                        color: PdfColors.grey,
                        fontWeight: pw.FontWeight.bold,
                      ),
                    ),
                    pw.Padding(padding: const pw.EdgeInsets.only(top: 20)),

                    pw.Text(
                      '想飞的乌龟',

                    ),
                    pw.Padding(padding: const pw.EdgeInsets.only(top: 20)),

                  ],
                ),
              ),

            ],
          ),
        ),

      ],
    ),
  ];
}

Future<Uint8List> generateResume(PdfPageFormat format, CustomData data) async {
  final doc = pw.Document(title: 'My Résumé', author: 'David PHAM-VAN');

  final profileImage = pw.MemoryImage(
    (await rootBundle.load('assets/profile.jpg')).buffer.asUint8List(),
  );

  final pageTheme = await _myPageTheme(format);

  doc.addPage(
    pw.MultiPage(
      pageTheme: pageTheme,
      build: (pw.Context context) => testUI(context, pageTheme, profileImage),
    ),
  );
  return doc.save();
}

Future<pw.PageTheme> _myPageTheme(PdfPageFormat format) async {
  return pw.PageTheme(
    theme: pw.ThemeData.withFont(
        base: await PdfGoogleFonts.notoSansSCRegular(),
        bold: await PdfGoogleFonts.notoSansSCBold(),
        icons: await PdfGoogleFonts.materialIcons(),
         ),

  );
}

Expected behavior
The text should be displayed correctly.

Screenshots

Flutter Doctor

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.32.8, on macOS 15.4.1 24E263 darwin-arm64, locale
    zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK version
    36.1.0-rc1)
[✓] Xcode - develop for iOS and macOS (Xcode 16.4)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2025.1)
[✓] Connected device (2 available)
    ! Error: Browsing on the local area network for Jian的iPhone. Ensure the
      device is unlocked and attached with a cable or associated with the same
      local area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code
      -27)
    ! Error: Browsing on the local area network for 康康的iPhone. Ensure the device
      is unlocked and attached with a cable or associated with the same local
      area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code
      -27)
[✓] Network resources

• No issues found!

Desktop (please complete the following information):

• iOS
• Android
• Browser
• Windows
• Linux

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
pdf version: "3.11.3", printing version: "5.14.2"
By the way, if I modify part of the content,“想飞的乌龟” to “想飞的乌龟123”， the text can be displayed, but some characters are displayed incorrectly.