7 files changed, 13 insertions, 12 deletions
diff --git a/core/fxcrt/cfx_bytestring.cpp b/core/fxcrt/cfx_bytestring.cpp
index ac390949ee..13b6673c70 100644
--- a/core/fxcrt/cfx_bytestring.cpp
+++ b/core/fxcrt/cfx_bytestring.cpp
@@ -427,7 +427,7 @@ FX_STRSIZE CFX_ByteString::Delete(FX_STRSIZE index, FX_STRSIZE count) {
     return old_length;
 
   ReallocBeforeWrite(old_length);
-  int chars_to_copy = old_length - removal_length + 1;
+  FX_STRSIZE chars_to_copy = old_length - removal_length + 1;
   memmove(m_pData->m_String + index, m_pData->m_String + removal_length,
           chars_to_copy);
   m_pData->m_nDataLength = old_length - count;
diff --git a/core/fxcrt/cfx_chariter.cpp b/core/fxcrt/cfx_chariter.cpp
index db94fb09f4..827e86967d 100644
--- a/core/fxcrt/cfx_chariter.cpp
+++ b/core/fxcrt/cfx_chariter.cpp
@@ -21,7 +21,7 @@ bool CFX_CharIter::Next(bool bPrev) {
       return false;
     m_nIndex--;
   } else {
-    if (m_nIndex + 1 >= m_wsText.GetLength())
+    if (static_cast<FX_STRSIZE>(m_nIndex + 1) >= m_wsText.GetLength())
       return false;
     m_nIndex++;
   }
@@ -33,7 +33,7 @@ wchar_t CFX_CharIter::GetChar() const {
 }
 
 void CFX_CharIter::SetAt(int32_t nIndex) {
-  if (nIndex < 0 || nIndex >= m_wsText.GetLength())
+  if (nIndex < 0 || static_cast<FX_STRSIZE>(nIndex) >= m_wsText.GetLength())
     return;
   m_nIndex = nIndex;
 }
@@ -43,7 +43,8 @@ int32_t CFX_CharIter::GetAt() const {
 }
 
 bool CFX_CharIter::IsEOF(bool bTail) const {
-  return bTail ? (m_nIndex + 1 == m_wsText.GetLength()) : (m_nIndex == 0);
+  return bTail ? (static_cast<FX_STRSIZE>(m_nIndex + 1) == m_wsText.GetLength())
+               : (m_nIndex == 0);
 }
 
 std::unique_ptr<IFX_CharIter> CFX_CharIter::Clone() const {
diff --git a/core/fxcrt/cfx_seekablestreamproxy.cpp b/core/fxcrt/cfx_seekablestreamproxy.cpp
index e610e0a9c3..da1170717a 100644
--- a/core/fxcrt/cfx_seekablestreamproxy.cpp
+++ b/core/fxcrt/cfx_seekablestreamproxy.cpp
@@ -98,8 +98,8 @@ void UTF16ToWChar(void* pBuffer, FX_STRSIZE iLength) {
 
   uint16_t* pSrc = static_cast<uint16_t*>(pBuffer);
   wchar_t* pDst = static_cast<wchar_t*>(pBuffer);
-  while (--iLength >= 0)
-    pDst[iLength] = static_cast<wchar_t>(pSrc[iLength]);
+  for (FX_STRSIZE i = 0; i < iLength; i++)
+    pDst[i] = static_cast<wchar_t>(pSrc[i]);
 }
 
 void SwapByteOrder(wchar_t* pStr, FX_STRSIZE iLength) {
diff --git a/core/fxcrt/cfx_string_data_template.h b/core/fxcrt/cfx_string_data_template.h
index e39f6a5dfd..eabb608818 100644
--- a/core/fxcrt/cfx_string_data_template.h
+++ b/core/fxcrt/cfx_string_data_template.h
@@ -21,7 +21,7 @@ class CFX_StringDataTemplate {
     // NUL char that is not included in |m_nAllocLength|.
     int overhead =
         offsetof(CFX_StringDataTemplate, m_String) + sizeof(CharType);
-    pdfium::base::CheckedNumeric<int> nSize = nLen;
+    pdfium::base::CheckedNumeric<FX_STRSIZE> nSize = nLen;
     nSize *= sizeof(CharType);
     nSize += overhead;
 
@@ -31,8 +31,8 @@ class CFX_StringDataTemplate {
     // by using this otherwise wasted space.
     nSize += 7;
     nSize &= ~7;
-    int totalSize = nSize.ValueOrDie();
-    int usableLen = (totalSize - overhead) / sizeof(CharType);
+    FX_STRSIZE totalSize = nSize.ValueOrDie();
+    FX_STRSIZE usableLen = (totalSize - overhead) / sizeof(CharType);
     ASSERT(usableLen >= nLen);
 
     void* pData = pdfium::base::PartitionAllocGeneric(
diff --git a/core/fxcrt/fx_basic.h b/core/fxcrt/fx_basic.h
index 47cce9a60f..1f05dfb627 100644
--- a/core/fxcrt/fx_basic.h
+++ b/core/fxcrt/fx_basic.h
@@ -43,7 +43,7 @@ class CFX_BinaryBuf {
   }
 
   void InsertBlock(FX_STRSIZE pos, const void* pBuf, FX_STRSIZE size);
-  void Delete(int start_index, int count);
+  void Delete(FX_STRSIZE start_index, FX_STRSIZE count);
 
   // Releases ownership of |m_pBuffer| and returns it.
   std::unique_ptr<uint8_t, FxFreeDeleter> DetachBuffer();
diff --git a/core/fxcrt/fx_basic_buffer.cpp b/core/fxcrt/fx_basic_buffer.cpp
index a359bdd5d0..310aec7faf 100644
--- a/core/fxcrt/fx_basic_buffer.cpp
+++ b/core/fxcrt/fx_basic_buffer.cpp
@@ -23,7 +23,7 @@ CFX_BinaryBuf::CFX_BinaryBuf(FX_STRSIZE size)
 
 CFX_BinaryBuf::~CFX_BinaryBuf() {}
 
-void CFX_BinaryBuf::Delete(int start_index, int count) {
+void CFX_BinaryBuf::Delete(FX_STRSIZE start_index, FX_STRSIZE count) {
   if (!m_pBuffer || start_index < 0 || count < 0 || count > m_DataSize ||
       start_index > m_DataSize - count) {
     return;
diff --git a/core/fxcrt/fx_basic_util.cpp b/core/fxcrt/fx_basic_util.cpp
index 05ab20472c..6f59f32fff 100644
--- a/core/fxcrt/fx_basic_util.cpp
+++ b/core/fxcrt/fx_basic_util.cpp
@@ -28,7 +28,7 @@ bool FX_atonum(const CFX_ByteStringC& strc, void* pData) {
   pdfium::base::CheckedNumeric<uint32_t> integer = 0;
   bool bNegative = false;
   bool bSigned = false;
-  int cc = 0;
+  FX_STRSIZE cc = 0;
   if (strc[0] == '+') {
     cc++;
     bSigned = true;