diff --git a/core/fpdfapi/font/cpdf_tounicodemap.cpp b/core/fpdfapi/font/cpdf_tounicodemap.cpp
index 1872d5d..96649e4 100644
--- a/core/fpdfapi/font/cpdf_tounicodemap.cpp
+++ b/core/fpdfapi/font/cpdf_tounicodemap.cpp
@@ -44,8 +44,8 @@
 CPDF_ToUnicodeMap::~CPDF_ToUnicodeMap() = default;
 
 WideString CPDF_ToUnicodeMap::Lookup(uint32_t charcode) const {
-  auto it = m_Map.find(charcode);
-  if (it == m_Map.end()) {
+  auto it = m_Multimap.find(charcode);
+  if (it == m_Multimap.end()) {
     if (!m_pBaseMap)
       return WideString();
     return m_pBaseMap->UnicodeFromCID(static_cast<uint16_t>(charcode));
@@ -64,7 +64,7 @@
 }
 
 uint32_t CPDF_ToUnicodeMap::ReverseLookup(wchar_t unicode) const {
-  for (const auto& pair : m_Map) {
+  for (const auto& pair : m_Multimap) {
     if (pair.second == static_cast<uint32_t>(unicode))
       return pair.first;
   }
@@ -190,12 +190,12 @@
 
       uint32_t value = value_or_error.value();
       for (uint32_t code = lowcode; code <= highcode; code++)
-        m_Map[code] = value++;
+        m_Multimap.emplace(code, value++);
     } else {
       for (uint32_t code = lowcode; code <= highcode; code++) {
         WideString retcode =
             code == lowcode ? destcode : StringDataAdd(destcode);
-        m_Map[code] = GetUnicode();
+        m_Multimap.emplace(code, GetUnicode());
         m_MultiCharBuf.AppendChar(retcode.GetLength());
         m_MultiCharBuf << retcode;
         destcode = std::move(retcode);
@@ -216,9 +216,9 @@
     return;
 
   if (len == 1) {
-    m_Map[srccode] = destcode[0];
+    m_Multimap.emplace(srccode, destcode[0]);
   } else {
-    m_Map[srccode] = GetUnicode();
+    m_Multimap.emplace(srccode, GetUnicode());
     m_MultiCharBuf.AppendChar(len);
     m_MultiCharBuf << destcode;
   }
diff --git a/core/fpdfapi/font/cpdf_tounicodemap.h b/core/fpdfapi/font/cpdf_tounicodemap.h
index 9eaf625..2872192 100644
--- a/core/fpdfapi/font/cpdf_tounicodemap.h
+++ b/core/fpdfapi/font/cpdf_tounicodemap.h
@@ -37,7 +37,7 @@
   uint32_t GetUnicode() const;
   void SetCode(uint32_t srccode, WideString destcode);
 
-  std::map<uint32_t, uint32_t> m_Map;
+  std::multimap<uint32_t, uint32_t> m_Multimap;
   UnownedPtr<const CPDF_CID2UnicodeMap> m_pBaseMap;
   CFX_WideTextBuf m_MultiCharBuf;
 };
diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index 3155191..98f85ce 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -29,7 +29,9 @@
 #include "testing/fx_string_testhelpers.h"
 #include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "testing/utils/file_util.h"
 #include "testing/utils/hash.h"
+#include "testing/utils/path_service.h"
 
 using pdfium::kHelloWorldChecksum;
 
@@ -234,6 +236,55 @@
 
 }  // namespace
 
+TEST_F(FPDFEditEmbedderTest, EmbedNotoSansSCFont) {
+  EXPECT_TRUE(CreateEmptyDocument());
+  ScopedFPDFPage page(FPDFPage_New(document(), 0, 400, 400));
+  std::string font_path;
+  ASSERT_TRUE(PathService::GetTestFilePath(
+      "fonts/third_party/NotoSansSC/NotoSansSC-Regular.subset.otf",
+      &font_path));
+
+  size_t file_length = 0;
+  std::unique_ptr<char, pdfium::FreeDeleter> font_data =
+      GetFileContents(font_path.c_str(), &file_length);
+  ASSERT(font_data);
+
+  ScopedFPDFFont font(FPDFText_LoadFont(
+      document(), reinterpret_cast<const uint8_t*>(font_data.get()),
+      file_length, FPDF_FONT_TRUETYPE, /*cid=*/true));
+  FPDF_PAGEOBJECT text_object =
+      FPDFPageObj_CreateTextObj(document(), font.get(), 20.0f);
+  EXPECT_TRUE(text_object);
+
+  // Test the characters which are either mapped to one single unicode or
+  // multiple unicodes in the embedded font.
+  ScopedFPDFWideString text = GetFPDFWideString(L"这是第一句。 这是第二行。");
+  EXPECT_TRUE(FPDFText_SetText(text_object, text.get()));
+
+  FPDFPageObj_Transform(text_object, 1, 0, 0, 1, 50, 200);
+  FPDFPage_InsertObject(page.get(), text_object);
+  EXPECT_TRUE(FPDFPage_GenerateContent(page.get()));
+
+#if defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
+#if defined(OS_APPLE)
+  const char kChecksum[] = "9a31fb87d1c6d2346bba22d1196041cd";
+#else
+  const char kChecksum[] = "5bb65e15fc0a685934cd5006dec08a76";
+#endif  // defined(OS_APPLE)
+#else
+#if defined(OS_WIN)
+  const char kChecksum[] = "89e8eef5d6ad18c542a92a0519954d0f";
+#else
+  const char kChecksum[] = "9a31fb87d1c6d2346bba22d1196041cd";
+#endif  // defined(OS_WIN)
+#endif  // defined(_SKIA_SUPPORT_) || defined(_SKIA_SUPPORT_PATHS_)
+  ScopedFPDFBitmap page_bitmap = RenderPage(page.get());
+  CompareBitmap(page_bitmap.get(), 400, 400, kChecksum);
+
+  EXPECT_TRUE(FPDF_SaveAsCopy(document(), this, 0));
+  VerifySavedDocument(400, 400, kChecksum);
+}
+
 TEST_F(FPDFEditEmbedderTest, EmptyCreation) {
   EXPECT_TRUE(CreateEmptyDocument());
   FPDF_PAGE page = FPDFPage_New(document(), 0, 640.0, 480.0);
diff --git a/fpdfsdk/fpdf_edittext.cpp b/fpdfsdk/fpdf_edittext.cpp
index b3815f8..4a4630e 100644
--- a/fpdfsdk/fpdf_edittext.cpp
+++ b/fpdfsdk/fpdf_edittext.cpp
@@ -157,7 +157,7 @@
 
 // Loads the charcode to unicode mapping into a stream
 CPDF_Stream* LoadUnicode(CPDF_Document* pDoc,
-                         const std::map<uint32_t, uint32_t>& to_unicode) {
+                         const std::multimap<uint32_t, uint32_t>& to_unicode) {
   // A map charcode->unicode
   std::map<uint32_t, uint32_t> char_to_uni;
   // A map <char_start, char_end> to vector v of unicode characters of size (end
@@ -355,7 +355,7 @@
   if (dwGlyphIndex == 0 || dwCurrentChar > kMaxUnicode)
     return nullptr;
 
-  std::map<uint32_t, uint32_t> to_unicode;
+  std::multimap<uint32_t, uint32_t> to_unicode;
   std::map<uint32_t, uint32_t> widths;
   while (true) {
     if (dwCurrentChar > kMaxUnicode)
@@ -363,7 +363,7 @@
 
     if (!pdfium::Contains(widths, dwGlyphIndex))
       widths[dwGlyphIndex] = pFont->GetGlyphWidth(dwGlyphIndex);
-    to_unicode[dwGlyphIndex] = dwCurrentChar;
+    to_unicode.emplace(dwGlyphIndex, dwCurrentChar);
     dwCurrentChar =
         FT_Get_Next_Char(pFont->GetFaceRec(), dwCurrentChar, &dwGlyphIndex);
     if (dwGlyphIndex == 0)
diff --git a/testing/resources/fonts/third_party/NotoSansSC/LICENSE.txt b/testing/resources/fonts/third_party/NotoSansSC/LICENSE.txt
new file mode 100644
index 0000000..70fbc7f
--- /dev/null
+++ b/testing/resources/fonts/third_party/NotoSansSC/LICENSE.txt
@@ -0,0 +1,78 @@
+Copyright 2018 The Noto Project Authors (github.com/googlei18n/noto-fonts)
+
+This Font Software is licensed under the SIL Open Font License,
+Version 1.1.
+
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font
+creation efforts of academic and linguistic communities, and to
+provide a free and open framework in which fonts may be shared and
+improved in partnership with others.
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply to
+any document created using the fonts or their derivatives.
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+"Original Version" refers to the collection of Font Software
+components as distributed by the Copyright Holder(s).
+"Modified Version" refers to any derivative made by adding to,
+deleting, or substituting -- in part or in whole -- any of the
+components of the Original Version, by changing formats or by porting
+the Font Software to a new environment.
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed,
+modify, redistribute, and sell modified and unmodified copies of the
+Font Software, subject to the following conditions:
+1) Neither the Font Software nor any of its individual components, in
+Original or Modified Versions, may be sold by itself.
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the
+corresponding Copyright Holder. This restriction only applies to the
+primary font name as presented to the users.
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created using
+the Font Software.
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.
diff --git a/testing/resources/fonts/third_party/NotoSansSC/NotoSansSC-Regular.subset.otf b/testing/resources/fonts/third_party/NotoSansSC/NotoSansSC-Regular.subset.otf
new file mode 100644
index 0000000..050c8b2
--- /dev/null
+++ b/testing/resources/fonts/third_party/NotoSansSC/NotoSansSC-Regular.subset.otf
Binary files differ
diff --git a/testing/resources/fonts/third_party/NotoSansSC/README.pdfium b/testing/resources/fonts/third_party/NotoSansSC/README.pdfium
new file mode 100644
index 0000000..8e07d2a
--- /dev/null
+++ b/testing/resources/fonts/third_party/NotoSansSC/README.pdfium
@@ -0,0 +1,19 @@
+Noto Sans SC Font:
+
+1. Source Origin
+Google's Internationalisation team's:
+https://github.com/googlei18n/noto-cjk
+
+2. LICENSE AND OPENSOURCE
+For license information, see the LICENSE.txt file
+
+3. Reason:
+This font file is used for the test FPDFEditEmbedderTest.EmbedNotoSansSCFont.
+The font file is included as a real-world example for testing PDFium's API to
+embed a CJK font into a PDF file, which contains multiple unicodes mapped to
+the same CID. See crbug.com/pdfium/1608 for details.
+
+Command to generate the font subset:
+$ pyftsubset NotoSansSC-Regular.otf --unicodes="U+0000884C,U+0000FA08,U+0000F906,U+000053E5,U+00008FD9,U+0000662F,U+00007B2C,U+00004E00,U+00003002,U+00004E8C,U+00002F00,U+00002F06"
+
+where pyftsubset comes from https://github.com/behdad/fonttools