Make CPVT_WordPlace more conformant with the prevailing idioms.

Add relational operators to replace CmpWord().
Leave CmpLine() for the moment as it saves some work.
Remove CmpSec() and just inline comparison of the one member.

Invert IsExist() as IsEmpty().  There is a big philosophical
discussion as to whether things that are empty exist.  I say
they do, but they're just empty.

Rename Default() to Reset().  Default sounds like a noun.
Add AdvanceSection() method and call as appropriate.


Change-Id: I01d9479f63a4860e0fd228255540d6d94dc24a9f
Reviewed-on: https://pdfium-review.googlesource.com/3139
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

8 files changed, 310 insertions, 369 deletions

diff --git a/core/fpdfdoc/cpdf_variabletext.cpp b/core/fpdfdoc/cpdf_variabletext.cpp
index 24dd9b065d..4e46969dc4 100644
--- a/core/fpdfdoc/cpdf_variabletext.cpp
+++ b/core/fpdfdoc/cpdf_variabletext.cpp
@@ -432,9 +432,7 @@ void CPDF_VariableText::SetText(const CFX_WideString& swText) {
           if (swText.GetAt(i + 1) == 0x0A)
             i += 1;
 
-          wp.nSecIndex++;
-          wp.nLineIndex = 0;
-          wp.nWordIndex = -1;
+          wp.AdvanceSection();
           AddSection(wp, secinfo);
         }
         break;
@@ -443,9 +441,7 @@ void CPDF_VariableText::SetText(const CFX_WideString& swText) {
           if (swText.GetAt(i + 1) == 0x0D)
             i += 1;
 
-          wp.nSecIndex++;
-          wp.nLineIndex = 0;
-          wp.nWordIndex = -1;
+          wp.AdvanceSection();
           AddSection(wp, secinfo);
         }
         break;
@@ -537,7 +533,7 @@ CPVT_WordPlace CPDF_VariableText::GetPrevWordPlace(
     return GetEndWordPlace();
 
   CSection* pSection = m_SectionArray[place.nSecIndex].get();
-  if (place.WordCmp(pSection->GetBeginWordPlace()) > 0)
+  if (place > pSection->GetBeginWordPlace())
     return pSection->GetPrevWordPlace(place);
   if (!pdfium::IndexInBounds(m_SectionArray, place.nSecIndex - 1))
     return GetBeginWordPlace();
@@ -552,7 +548,7 @@ CPVT_WordPlace CPDF_VariableText::GetNextWordPlace(
     return GetEndWordPlace();
 
   CSection* pSection = m_SectionArray[place.nSecIndex].get();
-  if (place.WordCmp(pSection->GetEndWordPlace()) < 0)
+  if (place < pSection->GetEndWordPlace())
     return pSection->GetNextWordPlace(place);
   if (!pdfium::IndexInBounds(m_SectionArray, place.nSecIndex + 1))
     return GetEndWordPlace();
@@ -638,8 +634,7 @@ CPVT_WordPlace CPDF_VariableText::GetDownWordPlace(
     return pSection->SearchWordPlace(pt.x - pSection->m_SecInfo.rcSection.left,
                                      temp);
   }
-  ++temp.nSecIndex;
-  temp.nLineIndex = 0;
+  temp.AdvanceSection();
   if (!pdfium::IndexInBounds(m_SectionArray, temp.nSecIndex))
     return place;
 
diff --git a/core/fpdfdoc/cpvt_wordplace.h b/core/fpdfdoc/cpvt_wordplace.h
index f4a6b087b9..c0a1a9cd5c 100644
--- a/core/fpdfdoc/cpvt_wordplace.h
+++ b/core/fpdfdoc/cpvt_wordplace.h
@@ -14,55 +14,55 @@ struct CPVT_WordPlace {
 
   CPVT_WordPlace(int32_t other_nSecIndex,
                  int32_t other_nLineIndex,
-                 int32_t other_nWordIndex) {
-    nSecIndex = other_nSecIndex;
-    nLineIndex = other_nLineIndex;
-    nWordIndex = other_nWordIndex;
+                 int32_t other_nWordIndex)
+      : nSecIndex(other_nSecIndex),
+        nLineIndex(other_nLineIndex),
+        nWordIndex(other_nWordIndex) {}
+
+  void Reset() {
+    nSecIndex = -1;
+    nLineIndex = -1;
+    nWordIndex = -1;
   }
 
-  void Default() { nSecIndex = nLineIndex = nWordIndex = -1; }
+  void AdvanceSection() {
+    nSecIndex++;
+    nLineIndex = 0;
+    nWordIndex = -1;
+  }
 
-  bool operator==(const CPVT_WordPlace& wp) const {
+  inline bool operator==(const CPVT_WordPlace& wp) const {
     return wp.nSecIndex == nSecIndex && wp.nLineIndex == nLineIndex &&
            wp.nWordIndex == nWordIndex;
   }
-
-  bool operator!=(const CPVT_WordPlace& wp) const { return !(*this == wp); }
-
-  inline int32_t WordCmp(const CPVT_WordPlace& wp) const {
-    if (nSecIndex > wp.nSecIndex)
-      return 1;
-    if (nSecIndex < wp.nSecIndex)
-      return -1;
-    if (nLineIndex > wp.nLineIndex)
-      return 1;
-    if (nLineIndex < wp.nLineIndex)
-      return -1;
-    if (nWordIndex > wp.nWordIndex)
-      return 1;
-    if (nWordIndex < wp.nWordIndex)
-      return -1;
-    return 0;
+  inline bool operator!=(const CPVT_WordPlace& wp) const {
+    return !(*this == wp);
   }
-
-  inline int32_t LineCmp(const CPVT_WordPlace& wp) const {
-    if (nSecIndex > wp.nSecIndex)
-      return 1;
-    if (nSecIndex < wp.nSecIndex)
-      return -1;
-    if (nLineIndex > wp.nLineIndex)
-      return 1;
-    if (nLineIndex < wp.nLineIndex)
-      return -1;
-    return 0;
+  inline bool operator<(const CPVT_WordPlace& wp) const {
+    if (nSecIndex != wp.nSecIndex)
+      return nSecIndex < wp.nSecIndex;
+    if (nLineIndex != wp.nLineIndex)
+      return nLineIndex < wp.nLineIndex;
+    return nWordIndex < wp.nWordIndex;
+  }
+  inline bool operator>(const CPVT_WordPlace& wp) const {
+    if (nSecIndex != wp.nSecIndex)
+      return nSecIndex > wp.nSecIndex;
+    if (nLineIndex != wp.nLineIndex)
+      return nLineIndex > wp.nLineIndex;
+    return nWordIndex > wp.nWordIndex;
+  }
+  inline bool operator<=(const CPVT_WordPlace& wp) const {
+    return *this < wp || *this == wp;
+  }
+  inline bool operator>=(const CPVT_WordPlace& wp) const {
+    return *this > wp || *this == wp;
   }
 
-  inline int32_t SecCmp(const CPVT_WordPlace& wp) const {
-    if (nSecIndex > wp.nSecIndex)
-      return 1;
-    if (nSecIndex < wp.nSecIndex)
-      return -1;
-    return 0;
+  inline int32_t LineCmp(const CPVT_WordPlace& wp) const {
+    if (nSecIndex != wp.nSecIndex)
+      return nSecIndex - wp.nSecIndex;
+    return nLineIndex - wp.nLineIndex;
   }
 
   int32_t nSecIndex;
diff --git a/core/fpdfdoc/cpvt_wordrange.h b/core/fpdfdoc/cpvt_wordrange.h
index b291e50e53..ed06d6f0de 100644
--- a/core/fpdfdoc/cpvt_wordrange.h
+++ b/core/fpdfdoc/cpvt_wordrange.h
@@ -7,49 +7,51 @@
 #ifndef CORE_FPDFDOC_CPVT_WORDRANGE_H_
 #define CORE_FPDFDOC_CPVT_WORDRANGE_H_
 
+#include <utility>
+
 #include "core/fpdfdoc/cpvt_wordplace.h"
 #include "core/fxcrt/fx_system.h"
 
 struct CPVT_WordRange {
   CPVT_WordRange() {}
 
-  CPVT_WordRange(const CPVT_WordPlace& begin, const CPVT_WordPlace& end) {
-    Set(begin, end);
+  CPVT_WordRange(const CPVT_WordPlace& begin, const CPVT_WordPlace& end)
+      : BeginPos(begin), EndPos(end) {
+    Normalize();
   }
 
-  void Default() {
-    BeginPos.Default();
-    EndPos.Default();
+  void Reset() {
+    BeginPos.Reset();
+    EndPos.Reset();
   }
 
   void Set(const CPVT_WordPlace& begin, const CPVT_WordPlace& end) {
     BeginPos = begin;
     EndPos = end;
-    SwapWordPlace();
+    Normalize();
   }
 
   void SetBeginPos(const CPVT_WordPlace& begin) {
     BeginPos = begin;
-    SwapWordPlace();
+    Normalize();
   }
 
   void SetEndPos(const CPVT_WordPlace& end) {
     EndPos = end;
-    SwapWordPlace();
+    Normalize();
   }
 
-  bool IsExist() const { return BeginPos != EndPos; }
-
-  bool operator!=(const CPVT_WordRange& wr) const {
-    return wr.BeginPos != BeginPos || wr.EndPos != EndPos;
+  inline bool IsEmpty() const { return BeginPos == EndPos; }
+  inline bool operator==(const CPVT_WordRange& wr) const {
+    return wr.BeginPos == BeginPos && wr.EndPos == EndPos;
+  }
+  inline bool operator!=(const CPVT_WordRange& wr) const {
+    return !(*this == wr);
   }
 
-  void SwapWordPlace() {
-    if (BeginPos.WordCmp(EndPos) > 0) {
-      CPVT_WordPlace place = EndPos;
-      EndPos = BeginPos;
-      BeginPos = place;
-    }
+  void Normalize() {
+    if (BeginPos > EndPos)
+      std::swap(BeginPos, EndPos);
   }
 
   CPVT_WordPlace BeginPos;
diff --git a/core/fpdfdoc/csection.cpp b/core/fpdfdoc/csection.cpp
index 6198d780fd..b6f45a274c 100644
--- a/core/fpdfdoc/csection.cpp
+++ b/core/fpdfdoc/csection.cpp
@@ -237,14 +237,14 @@ void CSection::ClearMidWords(int32_t nBeginIndex, int32_t nEndIndex) {
 void CSection::ClearWords(const CPVT_WordRange& PlaceRange) {
   CPVT_WordPlace SecBeginPos = GetBeginWordPlace();
   CPVT_WordPlace SecEndPos = GetEndWordPlace();
-  if (PlaceRange.BeginPos.WordCmp(SecBeginPos) >= 0) {
-    if (PlaceRange.EndPos.WordCmp(SecEndPos) <= 0) {
+  if (PlaceRange.BeginPos >= SecBeginPos) {
+    if (PlaceRange.EndPos <= SecEndPos) {
       ClearMidWords(PlaceRange.BeginPos.nWordIndex,
                     PlaceRange.EndPos.nWordIndex);
     } else {
       ClearRightWords(PlaceRange.BeginPos.nWordIndex);
     }
-  } else if (PlaceRange.EndPos.WordCmp(SecEndPos) <= 0) {
+  } else if (PlaceRange.EndPos <= SecEndPos) {
     ClearLeftWords(PlaceRange.EndPos.nWordIndex);
   } else {
     m_WordArray.clear();
diff --git a/fpdfsdk/fxedit/fxet_edit.cpp b/fpdfsdk/fxedit/fxet_edit.cpp
index 0a5c3d940f..20f584e183 100644
--- a/fpdfsdk/fxedit/fxet_edit.cpp
+++ b/fpdfsdk/fxedit/fxet_edit.cpp
@@ -459,23 +459,24 @@ CFXEU_Backspace::CFXEU_Backspace(CFX_Edit* pEdit,
 CFXEU_Backspace::~CFXEU_Backspace() {}
 
 void CFXEU_Backspace::Redo() {
-  if (m_pEdit) {
-    m_pEdit->SelectNone();
-    m_pEdit->SetCaret(m_wpOld);
-    m_pEdit->Backspace(false, true);
-  }
+  if (!m_pEdit)
+    return;
+
+  m_pEdit->SelectNone();
+  m_pEdit->SetCaret(m_wpOld);
+  m_pEdit->Backspace(false, true);
 }
 
 void CFXEU_Backspace::Undo() {
-  if (m_pEdit) {
-    m_pEdit->SelectNone();
-    m_pEdit->SetCaret(m_wpNew);
-    if (m_wpNew.SecCmp(m_wpOld) != 0) {
-      m_pEdit->InsertReturn(&m_SecProps, &m_WordProps, false, true);
-    } else {
-      m_pEdit->InsertWord(m_Word, m_nCharset, &m_WordProps, false, true);
-    }
-  }
+  if (!m_pEdit)
+    return;
+
+  m_pEdit->SelectNone();
+  m_pEdit->SetCaret(m_wpNew);
+  if (m_wpNew.nSecIndex != m_wpOld.nSecIndex)
+    m_pEdit->InsertReturn(&m_SecProps, &m_WordProps, false, true);
+  else
+    m_pEdit->InsertWord(m_Word, m_nCharset, &m_WordProps, false, true);
 }
 
 CFXEU_Delete::CFXEU_Delete(CFX_Edit* pEdit,
@@ -591,7 +592,7 @@ CFX_ByteString CFX_Edit::GetEditAppearanceStream(CFX_Edit* pEdit,
 
   while (pIterator->NextWord()) {
     CPVT_WordPlace place = pIterator->GetAt();
-    if (pRange && place.WordCmp(pRange->EndPos) > 0)
+    if (pRange && place > pRange->EndPos)
       break;
 
     if (bContinuous) {
@@ -689,7 +690,7 @@ CFX_ByteString CFX_Edit::GetSelectAppearanceStream(
     CFX_Edit* pEdit,
     const CFX_PointF& ptOffset,
     const CPVT_WordRange* pRange) {
-  if (!pRange || !pRange->IsExist())
+  if (!pRange || pRange->IsEmpty())
     return CFX_ByteString();
 
   CFX_Edit_Iterator* pIterator = pEdit->GetIterator();
@@ -698,7 +699,7 @@ CFX_ByteString CFX_Edit::GetSelectAppearanceStream(
   CFX_ByteTextBuf sRet;
   while (pIterator->NextWord()) {
     CPVT_WordPlace place = pIterator->GetAt();
-    if (place.WordCmp(pRange->EndPos) > 0)
+    if (place > pRange->EndPos)
       break;
 
     CPVT_Word word;
@@ -757,12 +758,11 @@ void CFX_Edit::DrawEdit(CFX_RenderDevice* pDevice,
     CPVT_WordPlace oldplace;
     while (pIterator->NextWord()) {
       CPVT_WordPlace place = pIterator->GetAt();
-      if (pRange && place.WordCmp(pRange->EndPos) > 0)
+      if (pRange && place > pRange->EndPos)
         break;
 
-      if (wrSelect.IsExist()) {
-        bSelect = place.WordCmp(wrSelect.BeginPos) > 0 &&
-                  place.WordCmp(wrSelect.EndPos) <= 0;
+      if (!wrSelect.IsEmpty()) {
+        bSelect = place > wrSelect.BeginPos && place <= wrSelect.EndPos;
         crCurFill = bSelect ? crWhite : crTextFill;
       }
       if (pSystemHandler && pSystemHandler->IsSelectionImplemented()) {
@@ -980,42 +980,36 @@ void CFX_Edit::SetSel(int32_t nStartChar, int32_t nEndChar) {
 }
 
 void CFX_Edit::SetSel(const CPVT_WordPlace& begin, const CPVT_WordPlace& end) {
-  if (m_pVT->IsValid()) {
-    SelectNone();
-
-    m_SelState.Set(begin, end);
-
-    SetCaret(m_SelState.EndPos);
+  if (!m_pVT->IsValid())
+    return;
 
-    if (m_SelState.IsExist()) {
-      ScrollToCaret();
-      Refresh();
-      SetCaretInfo();
-    } else {
-      ScrollToCaret();
-      SetCaretInfo();
-    }
-  }
+  SelectNone();
+  m_SelState.Set(begin, end);
+  SetCaret(m_SelState.EndPos);
+  ScrollToCaret();
+  if (!m_SelState.IsEmpty())
+    Refresh();
+  SetCaretInfo();
 }
 
 void CFX_Edit::GetSel(int32_t& nStartChar, int32_t& nEndChar) const {
   nStartChar = -1;
   nEndChar = -1;
+  if (!m_pVT->IsValid())
+    return;
 
-  if (m_pVT->IsValid()) {
-    if (m_SelState.IsExist()) {
-      if (m_SelState.BeginPos.WordCmp(m_SelState.EndPos) < 0) {
-        nStartChar = m_pVT->WordPlaceToWordIndex(m_SelState.BeginPos);
-        nEndChar = m_pVT->WordPlaceToWordIndex(m_SelState.EndPos);
-      } else {
-        nStartChar = m_pVT->WordPlaceToWordIndex(m_SelState.EndPos);
-        nEndChar = m_pVT->WordPlaceToWordIndex(m_SelState.BeginPos);
-      }
-    } else {
-      nStartChar = m_pVT->WordPlaceToWordIndex(m_wpCaret);
-      nEndChar = m_pVT->WordPlaceToWordIndex(m_wpCaret);
-    }
+  if (m_SelState.IsEmpty()) {
+    nStartChar = m_pVT->WordPlaceToWordIndex(m_wpCaret);
+    nEndChar = m_pVT->WordPlaceToWordIndex(m_wpCaret);
+    return;
   }
+  if (m_SelState.BeginPos < m_SelState.EndPos) {
+    nStartChar = m_pVT->WordPlaceToWordIndex(m_SelState.BeginPos);
+    nEndChar = m_pVT->WordPlaceToWordIndex(m_SelState.EndPos);
+    return;
+  }
+  nStartChar = m_pVT->WordPlaceToWordIndex(m_SelState.EndPos);
+  nEndChar = m_pVT->WordPlaceToWordIndex(m_SelState.BeginPos);
 }
 
 int32_t CFX_Edit::GetCaret() const {
@@ -1031,7 +1025,6 @@ CPVT_WordPlace CFX_Edit::GetCaretWordPlace() const {
 
 CFX_WideString CFX_Edit::GetText() const {
   CFX_WideString swRet;
-
   if (!m_pVT->IsValid())
     return swRet;
 
@@ -1042,22 +1035,17 @@ CFX_WideString CFX_Edit::GetText() const {
   CPVT_WordPlace oldplace = pIterator->GetAt();
   while (pIterator->NextWord()) {
     CPVT_WordPlace place = pIterator->GetAt();
-
     if (pIterator->GetWord(wordinfo))
       swRet += wordinfo.Word;
-
-    if (oldplace.SecCmp(place) != 0)
+    if (oldplace.nSecIndex != place.nSecIndex)
       swRet += L"\r\n";
-
     oldplace = place;
   }
-
   return swRet;
 }
 
 CFX_WideString CFX_Edit::GetRangeText(const CPVT_WordRange& range) const {
   CFX_WideString swRet;
-
   if (!m_pVT->IsValid())
     return swRet;
 
@@ -1071,18 +1059,14 @@ CFX_WideString CFX_Edit::GetRangeText(const CPVT_WordRange& range) const {
   CPVT_WordPlace oldplace = wrTemp.BeginPos;
   while (pIterator->NextWord()) {
     CPVT_WordPlace place = pIterator->GetAt();
-    if (place.WordCmp(wrTemp.EndPos) > 0)
+    if (place > wrTemp.EndPos)
       break;
-
     if (pIterator->GetWord(wordinfo))
       swRet += wordinfo.Word;
-
-    if (oldplace.SecCmp(place) != 0)
+    if (oldplace.nSecIndex != place.nSecIndex)
       swRet += L"\r\n";
-
     oldplace = place;
   }
-
   return swRet;
 }
 
@@ -1242,27 +1226,25 @@ void CFX_Edit::SetContentChanged() {
 }
 
 void CFX_Edit::SelectAll() {
-  if (m_pVT->IsValid()) {
-    m_SelState = CFX_Edit_Select(GetWholeWordRange());
-    SetCaret(m_SelState.EndPos);
-
-    ScrollToCaret();
-    Refresh();
-    SetCaretInfo();
-  }
+  if (!m_pVT->IsValid())
+    return;
+  m_SelState = CFX_Edit_Select(GetWholeWordRange());
+  SetCaret(m_SelState.EndPos);
+  ScrollToCaret();
+  Refresh();
+  SetCaretInfo();
 }
 
 void CFX_Edit::SelectNone() {
-  if (m_pVT->IsValid()) {
-    if (m_SelState.IsExist()) {
-      m_SelState.Default();
-      Refresh();
-    }
-  }
+  if (!m_pVT->IsValid() || m_SelState.IsEmpty())
+    return;
+
+  m_SelState.Reset();
+  Refresh();
 }
 
 bool CFX_Edit::IsSelected() const {
-  return m_SelState.IsExist();
+  return !m_SelState.IsEmpty();
 }
 
 CFX_PointF CFX_Edit::VTToEdit(const CFX_PointF& point) const {
@@ -1520,12 +1502,11 @@ void CFX_Edit::RefreshWordRange(const CPVT_WordRange& wr) {
 
   while (pIterator->NextWord()) {
     place = pIterator->GetAt();
-    if (place.WordCmp(wrTemp.EndPos) > 0)
+    if (place > wrTemp.EndPos)
       break;
 
     pIterator->GetWord(wordinfo);
     pIterator->GetLine(lineinfo);
-
     if (place.LineCmp(wrTemp.BeginPos) == 0 ||
         place.LineCmp(wrTemp.EndPos) == 0) {
       CFX_FloatRect rcWord(wordinfo.ptWord.x,
@@ -1589,7 +1570,7 @@ void CFX_Edit::SetCaretInfo() {
       }
 
       m_bNotifyFlag = true;
-      m_pNotify->IOnSetCaret(!m_SelState.IsExist(), VTToEdit(ptHead),
+      m_pNotify->IOnSetCaret(m_SelState.IsEmpty(), VTToEdit(ptHead),
                              VTToEdit(ptFoot), m_wpCaret);
       m_bNotifyFlag = false;
     }
@@ -1597,256 +1578,246 @@ void CFX_Edit::SetCaretInfo() {
 }
 
 void CFX_Edit::SetCaret(int32_t nPos) {
-  if (m_pVT->IsValid()) {
-    SelectNone();
-    SetCaret(m_pVT->WordIndexToWordPlace(nPos));
-    m_SelState.Set(m_wpCaret, m_wpCaret);
+  if (!m_pVT->IsValid())
+    return;
 
-    ScrollToCaret();
-    SetCaretOrigin();
-    SetCaretInfo();
-  }
+  SelectNone();
+  SetCaret(m_pVT->WordIndexToWordPlace(nPos));
+  m_SelState.Set(m_wpCaret, m_wpCaret);
+  ScrollToCaret();
+  SetCaretOrigin();
+  SetCaretInfo();
 }
 
 void CFX_Edit::OnMouseDown(const CFX_PointF& point, bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    SelectNone();
-    SetCaret(m_pVT->SearchWordPlace(EditToVT(point)));
-    m_SelState.Set(m_wpCaret, m_wpCaret);
+  if (!m_pVT->IsValid())
+    return;
 
-    ScrollToCaret();
-    SetCaretOrigin();
-    SetCaretInfo();
-  }
+  SelectNone();
+  SetCaret(m_pVT->SearchWordPlace(EditToVT(point)));
+  m_SelState.Set(m_wpCaret, m_wpCaret);
+  ScrollToCaret();
+  SetCaretOrigin();
+  SetCaretInfo();
 }
 
 void CFX_Edit::OnMouseMove(const CFX_PointF& point, bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    SetCaret(m_pVT->SearchWordPlace(EditToVT(point)));
+  if (!m_pVT->IsValid())
+    return;
 
-    if (m_wpCaret != m_wpOldCaret) {
-      m_SelState.SetEndPos(m_wpCaret);
+  SetCaret(m_pVT->SearchWordPlace(EditToVT(point)));
+  if (m_wpCaret == m_wpOldCaret)
+    return;
 
-      ScrollToCaret();
-      Refresh();
-      SetCaretOrigin();
-      SetCaretInfo();
-    }
-  }
+  m_SelState.SetEndPos(m_wpCaret);
+  ScrollToCaret();
+  Refresh();
+  SetCaretOrigin();
+  SetCaretInfo();
 }
 
 void CFX_Edit::OnVK_UP(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    SetCaret(m_pVT->GetUpWordPlace(m_wpCaret, m_ptCaret));
-
-    if (bShift) {
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
-      else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
+  if (!m_pVT->IsValid())
+    return;
 
-      if (m_wpOldCaret != m_wpCaret) {
-        ScrollToCaret();
-        Refresh();
-        SetCaretInfo();
-      }
-    } else {
-      SelectNone();
+  SetCaret(m_pVT->GetUpWordPlace(m_wpCaret, m_ptCaret));
+  if (bShift) {
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
 
+    if (m_wpOldCaret != m_wpCaret) {
       ScrollToCaret();
+      Refresh();
       SetCaretInfo();
     }
+  } else {
+    SelectNone();
+    ScrollToCaret();
+    SetCaretInfo();
   }
 }
 
 void CFX_Edit::OnVK_DOWN(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    SetCaret(m_pVT->GetDownWordPlace(m_wpCaret, m_ptCaret));
-
-    if (bShift) {
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
-      else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
+  if (!m_pVT->IsValid())
+    return;
 
-      if (m_wpOldCaret != m_wpCaret) {
-        ScrollToCaret();
-        Refresh();
-        SetCaretInfo();
-      }
-    } else {
-      SelectNone();
+  SetCaret(m_pVT->GetDownWordPlace(m_wpCaret, m_ptCaret));
+  if (bShift) {
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
 
+    if (m_wpOldCaret != m_wpCaret) {
       ScrollToCaret();
+      Refresh();
       SetCaretInfo();
     }
+  } else {
+    SelectNone();
+    ScrollToCaret();
+    SetCaretInfo();
   }
 }
 
 void CFX_Edit::OnVK_LEFT(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    if (bShift) {
-      if (m_wpCaret == m_pVT->GetLineBeginPlace(m_wpCaret) &&
-          m_wpCaret != m_pVT->GetSectionBeginPlace(m_wpCaret))
-        SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
+  if (!m_pVT->IsValid())
+    return;
 
+  if (bShift) {
+    if (m_wpCaret == m_pVT->GetLineBeginPlace(m_wpCaret) &&
+        m_wpCaret != m_pVT->GetSectionBeginPlace(m_wpCaret)) {
       SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
+    }
+    SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
 
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
+    if (m_wpOldCaret != m_wpCaret) {
+      ScrollToCaret();
+      Refresh();
+      SetCaretInfo();
+    }
+  } else {
+    if (!m_SelState.IsEmpty()) {
+      if (m_SelState.BeginPos < m_SelState.EndPos)
+        SetCaret(m_SelState.BeginPos);
       else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
+        SetCaret(m_SelState.EndPos);
 
-      if (m_wpOldCaret != m_wpCaret) {
-        ScrollToCaret();
-        Refresh();
-        SetCaretInfo();
-      }
+      SelectNone();
+      ScrollToCaret();
+      SetCaretInfo();
     } else {
-      if (m_SelState.IsExist()) {
-        if (m_SelState.BeginPos.WordCmp(m_SelState.EndPos) < 0)
-          SetCaret(m_SelState.BeginPos);
-        else
-          SetCaret(m_SelState.EndPos);
-
-        SelectNone();
-        ScrollToCaret();
-        SetCaretInfo();
-      } else {
-        if (m_wpCaret == m_pVT->GetLineBeginPlace(m_wpCaret) &&
-            m_wpCaret != m_pVT->GetSectionBeginPlace(m_wpCaret))
-          SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
-
+      if (m_wpCaret == m_pVT->GetLineBeginPlace(m_wpCaret) &&
+          m_wpCaret != m_pVT->GetSectionBeginPlace(m_wpCaret)) {
         SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
-
-        ScrollToCaret();
-        SetCaretOrigin();
-        SetCaretInfo();
       }
+      SetCaret(m_pVT->GetPrevWordPlace(m_wpCaret));
+      ScrollToCaret();
+      SetCaretOrigin();
+      SetCaretInfo();
     }
   }
 }
 
 void CFX_Edit::OnVK_RIGHT(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    if (bShift) {
+  if (!m_pVT->IsValid())
+    return;
+
+  if (bShift) {
+    SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
+    if (m_wpCaret == m_pVT->GetLineEndPlace(m_wpCaret) &&
+        m_wpCaret != m_pVT->GetSectionEndPlace(m_wpCaret))
       SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
 
-      if (m_wpCaret == m_pVT->GetLineEndPlace(m_wpCaret) &&
-          m_wpCaret != m_pVT->GetSectionEndPlace(m_wpCaret))
-        SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
 
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
+    if (m_wpOldCaret != m_wpCaret) {
+      ScrollToCaret();
+      Refresh();
+      SetCaretInfo();
+    }
+  } else {
+    if (!m_SelState.IsEmpty()) {
+      if (m_SelState.BeginPos > m_SelState.EndPos)
+        SetCaret(m_SelState.BeginPos);
       else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
+        SetCaret(m_SelState.EndPos);
 
-      if (m_wpOldCaret != m_wpCaret) {
-        ScrollToCaret();
-        Refresh();
-        SetCaretInfo();
-      }
+      SelectNone();
+      ScrollToCaret();
+      SetCaretInfo();
     } else {
-      if (m_SelState.IsExist()) {
-        if (m_SelState.BeginPos.WordCmp(m_SelState.EndPos) > 0)
-          SetCaret(m_SelState.BeginPos);
-        else
-          SetCaret(m_SelState.EndPos);
-
-        SelectNone();
-        ScrollToCaret();
-        SetCaretInfo();
-      } else {
+      SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
+      if (m_wpCaret == m_pVT->GetLineEndPlace(m_wpCaret) &&
+          m_wpCaret != m_pVT->GetSectionEndPlace(m_wpCaret)) {
         SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
-
-        if (m_wpCaret == m_pVT->GetLineEndPlace(m_wpCaret) &&
-            m_wpCaret != m_pVT->GetSectionEndPlace(m_wpCaret))
-          SetCaret(m_pVT->GetNextWordPlace(m_wpCaret));
-
-        ScrollToCaret();
-        SetCaretOrigin();
-        SetCaretInfo();
       }
+      ScrollToCaret();
+      SetCaretOrigin();
+      SetCaretInfo();
     }
   }
 }
 
 void CFX_Edit::OnVK_HOME(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    if (bShift) {
+  if (!m_pVT->IsValid())
+    return;
+
+  if (bShift) {
+    if (bCtrl)
+      SetCaret(m_pVT->GetBeginWordPlace());
+    else
+      SetCaret(m_pVT->GetLineBeginPlace(m_wpCaret));
+
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
+
+    ScrollToCaret();
+    Refresh();
+    SetCaretInfo();
+  } else {
+    if (!m_SelState.IsEmpty()) {
+      SetCaret(std::min(m_SelState.BeginPos, m_SelState.EndPos));
+      SelectNone();
+      ScrollToCaret();
+      SetCaretInfo();
+    } else {
       if (bCtrl)
         SetCaret(m_pVT->GetBeginWordPlace());
       else
         SetCaret(m_pVT->GetLineBeginPlace(m_wpCaret));
 
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
-      else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
-
       ScrollToCaret();
-      Refresh();
+      SetCaretOrigin();
       SetCaretInfo();
-    } else {
-      if (m_SelState.IsExist()) {
-        if (m_SelState.BeginPos.WordCmp(m_SelState.EndPos) < 0)
-          SetCaret(m_SelState.BeginPos);
-        else
-          SetCaret(m_SelState.EndPos);
-
-        SelectNone();
-        ScrollToCaret();
-        SetCaretInfo();
-      } else {
-        if (bCtrl)
-          SetCaret(m_pVT->GetBeginWordPlace());
-        else
-          SetCaret(m_pVT->GetLineBeginPlace(m_wpCaret));
-
-        ScrollToCaret();
-        SetCaretOrigin();
-        SetCaretInfo();
-      }
     }
   }
 }
 
 void CFX_Edit::OnVK_END(bool bShift, bool bCtrl) {
-  if (m_pVT->IsValid()) {
-    if (bShift) {
+  if (!m_pVT->IsValid())
+    return;
+
+  if (bShift) {
+    if (bCtrl)
+      SetCaret(m_pVT->GetEndWordPlace());
+    else
+      SetCaret(m_pVT->GetLineEndPlace(m_wpCaret));
+
+    if (m_SelState.IsEmpty())
+      m_SelState.Set(m_wpOldCaret, m_wpCaret);
+    else
+      m_SelState.SetEndPos(m_wpCaret);
+
+    ScrollToCaret();
+    Refresh();
+    SetCaretInfo();
+  } else {
+    if (!m_SelState.IsEmpty()) {
+      SetCaret(std::max(m_SelState.BeginPos, m_SelState.EndPos));
+      SelectNone();
+      ScrollToCaret();
+      SetCaretInfo();
+    } else {
       if (bCtrl)
         SetCaret(m_pVT->GetEndWordPlace());
       else
         SetCaret(m_pVT->GetLineEndPlace(m_wpCaret));
 
-      if (m_SelState.IsExist())
-        m_SelState.SetEndPos(m_wpCaret);
-      else
-        m_SelState.Set(m_wpOldCaret, m_wpCaret);
-
       ScrollToCaret();
-      Refresh();
+      SetCaretOrigin();
       SetCaretInfo();
-    } else {
-      if (m_SelState.IsExist()) {
-        if (m_SelState.BeginPos.WordCmp(m_SelState.EndPos) > 0)
-          SetCaret(m_SelState.BeginPos);
-        else
-          SetCaret(m_SelState.EndPos);
-
-        SelectNone();
-        ScrollToCaret();
-        SetCaretInfo();
-      } else {
-        if (bCtrl)
-          SetCaret(m_pVT->GetEndWordPlace());
-        else
-          SetCaret(m_pVT->GetLineEndPlace(m_wpCaret));
-
-        ScrollToCaret();
-        SetCaretOrigin();
-        SetCaretInfo();
-      }
     }
   }
 }
@@ -1928,7 +1899,7 @@ bool CFX_Edit::Backspace(bool bAddUndo, bool bPaint) {
     return false;
 
   if (bAddUndo && m_bEnableUndo) {
-    if (m_wpCaret.SecCmp(m_wpOldCaret) != 0) {
+    if (m_wpCaret.nSecIndex != m_wpOldCaret.nSecIndex) {
       AddEditUndoItem(pdfium::MakeUnique<CFXEU_Backspace>(
           this, m_wpOldCaret, m_wpCaret, word.Word, word.nCharset,
           section.SecProps, section.WordProps));
@@ -2003,7 +1974,7 @@ bool CFX_Edit::Empty() {
 }
 
 bool CFX_Edit::Clear(bool bAddUndo, bool bPaint) {
-  if (!m_pVT->IsValid() || !m_SelState.IsExist())
+  if (!m_pVT->IsValid() || m_SelState.IsEmpty())
     return false;
 
   CPVT_WordRange range = m_SelState.ConvertToWordRange();
@@ -2255,9 +2226,9 @@ CPVT_WordRange CFX_Edit_Select::ConvertToWordRange() const {
   return CPVT_WordRange(BeginPos, EndPos);
 }
 
-void CFX_Edit_Select::Default() {
-  BeginPos.Default();
-  EndPos.Default();
+void CFX_Edit_Select::Reset() {
+  BeginPos.Reset();
+  EndPos.Reset();
 }
 
 void CFX_Edit_Select::Set(const CPVT_WordPlace& begin,
@@ -2274,8 +2245,8 @@ void CFX_Edit_Select::SetEndPos(const CPVT_WordPlace& end) {
   EndPos = end;
 }
 
-bool CFX_Edit_Select::IsExist() const {
-  return BeginPos != EndPos;
+bool CFX_Edit_Select::IsEmpty() const {
+  return BeginPos == EndPos;
 }
 
 CFX_Edit_RectArray::CFX_Edit_RectArray() {}
diff --git a/fpdfsdk/fxedit/fxet_edit.h b/fpdfsdk/fxedit/fxet_edit.h
index 4fcb5569c3..08a13a87bd 100644
--- a/fpdfsdk/fxedit/fxet_edit.h
+++ b/fpdfsdk/fxedit/fxet_edit.h
@@ -90,13 +90,13 @@ class CFX_Edit_Select {
   CFX_Edit_Select(const CPVT_WordPlace& begin, const CPVT_WordPlace& end);
   explicit CFX_Edit_Select(const CPVT_WordRange& range);
 
-  void Default();
+  void Reset();
   void Set(const CPVT_WordPlace& begin, const CPVT_WordPlace& end);
   void SetBeginPos(const CPVT_WordPlace& begin);
   void SetEndPos(const CPVT_WordPlace& end);
 
   CPVT_WordRange ConvertToWordRange() const;
-  bool IsExist() const;
+  bool IsEmpty() const;
 
   CPVT_WordPlace BeginPos;
   CPVT_WordPlace EndPos;
diff --git a/fpdfsdk/pdfwindow/PWL_Edit.cpp b/fpdfsdk/pdfwindow/PWL_Edit.cpp
index f84c38e23b..4b9e0d2f49 100644
--- a/fpdfsdk/pdfwindow/PWL_Edit.cpp
+++ b/fpdfsdk/pdfwindow/PWL_Edit.cpp
@@ -6,6 +6,7 @@
 
 #include "fpdfsdk/pdfwindow/PWL_Edit.h"
 
+#include <algorithm>
 #include <memory>
 #include <vector>
 
@@ -791,21 +792,8 @@ void CPWL_Edit::OnInsertText(const CPVT_WordPlace& place,
 
 CPVT_WordRange CPWL_Edit::CombineWordRange(const CPVT_WordRange& wr1,
                                            const CPVT_WordRange& wr2) {
-  CPVT_WordRange wrRet;
-
-  if (wr1.BeginPos.WordCmp(wr2.BeginPos) < 0) {
-    wrRet.BeginPos = wr1.BeginPos;
-  } else {
-    wrRet.BeginPos = wr2.BeginPos;
-  }
-
-  if (wr1.EndPos.WordCmp(wr2.EndPos) < 0) {
-    wrRet.EndPos = wr2.EndPos;
-  } else {
-    wrRet.EndPos = wr1.EndPos;
-  }
-
-  return wrRet;
+  return CPVT_WordRange(std::min(wr1.BeginPos, wr2.BeginPos),
+                        std::max(wr1.EndPos, wr2.EndPos));
 }
 
 CPVT_WordRange CPWL_Edit::GetLatinWordsRange(const CFX_PointF& point) const {
diff --git a/fpdfsdk/pdfwindow/PWL_Utils.cpp b/fpdfsdk/pdfwindow/PWL_Utils.cpp
index f78b590150..08b5e3013a 100644
--- a/fpdfsdk/pdfwindow/PWL_Utils.cpp
+++ b/fpdfsdk/pdfwindow/PWL_Utils.cpp
@@ -26,28 +26,13 @@ CFX_FloatRect CPWL_Utils::OffsetRect(const CFX_FloatRect& rect,
 
 CPVT_WordRange CPWL_Utils::OverlapWordRange(const CPVT_WordRange& wr1,
                                             const CPVT_WordRange& wr2) {
-  CPVT_WordRange wrRet;
-
-  if (wr2.EndPos.WordCmp(wr1.BeginPos) < 0 ||
-      wr2.BeginPos.WordCmp(wr1.EndPos) > 0)
-    return wrRet;
-  if (wr1.EndPos.WordCmp(wr2.BeginPos) < 0 ||
-      wr1.BeginPos.WordCmp(wr2.EndPos) > 0)
-    return wrRet;
-
-  if (wr1.BeginPos.WordCmp(wr2.BeginPos) < 0) {
-    wrRet.BeginPos = wr2.BeginPos;
-  } else {
-    wrRet.BeginPos = wr1.BeginPos;
+  if (wr2.EndPos < wr1.BeginPos || wr2.BeginPos > wr1.EndPos ||
+      wr1.EndPos < wr2.BeginPos || wr1.BeginPos > wr2.EndPos) {
+    return CPVT_WordRange();
   }
 
-  if (wr1.EndPos.WordCmp(wr2.EndPos) < 0) {
-    wrRet.EndPos = wr1.EndPos;
-  } else {
-    wrRet.EndPos = wr2.EndPos;
-  }
-
-  return wrRet;
+  return CPVT_WordRange(std::max(wr1.BeginPos, wr2.BeginPos),
+                        std::min(wr1.EndPos, wr2.EndPos));
 }
 
 CFX_ByteString CPWL_Utils::GetAP_Check(const CFX_FloatRect& crBBox) {