Prepare for converting FX_STRSIZE int->size_t

When turning on this conversion a number of typing issues and other nits where
found in the code base that can be merged in without actually changing the
underlying type. Landing these changes before the type change CL, since there is
a high likelihood that the type change will need to be rolled back, since it is
high risk.

BUG=pdfium:828

Change-Id: I587443d9090055963446485a1aacb8772eb5ca64
Reviewed-on: https://pdfium-review.googlesource.com/12810
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

4 files changed, 25 insertions, 24 deletions

diff --git a/core/fpdfapi/font/cpdf_cmap.cpp b/core/fpdfapi/font/cpdf_cmap.cpp
index 9e8c48bb27..659139f687 100644
--- a/core/fpdfapi/font/cpdf_cmap.cpp
+++ b/core/fpdfapi/font/cpdf_cmap.cpp
@@ -434,46 +434,46 @@ int CPDF_CMap::CountChar(const char* pString, int size) const {
 int CPDF_CMap::AppendChar(char* str, uint32_t charcode) const {
   switch (m_CodingScheme) {
     case OneByte:
-      str[0] = (uint8_t)charcode;
+      str[0] = static_cast<char>(charcode);
       return 1;
     case TwoBytes:
-      str[0] = (uint8_t)(charcode / 256);
-      str[1] = (uint8_t)(charcode % 256);
+      str[0] = static_cast<char>(charcode / 256);
+      str[1] = static_cast<char>(charcode % 256);
       return 2;
     case MixedTwoBytes:
-      if (charcode < 0x100 && !m_MixedTwoByteLeadingBytes[(uint8_t)charcode]) {
-        str[0] = (uint8_t)charcode;
+      if (charcode < 0x100 && !m_MixedTwoByteLeadingBytes[charcode]) {
+        str[0] = static_cast<char>(charcode);
         return 1;
       }
-      str[0] = (uint8_t)(charcode >> 8);
-      str[1] = (uint8_t)charcode;
+      str[0] = static_cast<char>(charcode >> 8);
+      str[1] = static_cast<char>(charcode);
       return 2;
     case MixedFourBytes:
       if (charcode < 0x100) {
-        int iSize =
-            GetFourByteCharSizeImpl(charcode, m_MixedFourByteLeadingRanges);
+        int iSize = static_cast<int>(
+            GetFourByteCharSizeImpl(charcode, m_MixedFourByteLeadingRanges));
         if (iSize == 0)
           iSize = 1;
-        str[iSize - 1] = (uint8_t)charcode;
+        str[iSize - 1] = static_cast<char>(charcode);
         if (iSize > 1)
           memset(str, 0, iSize - 1);
         return iSize;
       }
       if (charcode < 0x10000) {
-        str[0] = (uint8_t)(charcode >> 8);
-        str[1] = (uint8_t)charcode;
+        str[0] = static_cast<char>(charcode >> 8);
+        str[1] = static_cast<char>(charcode);
         return 2;
       }
       if (charcode < 0x1000000) {
-        str[0] = (uint8_t)(charcode >> 16);
-        str[1] = (uint8_t)(charcode >> 8);
-        str[2] = (uint8_t)charcode;
+        str[0] = static_cast<char>(charcode >> 16);
+        str[1] = static_cast<char>(charcode >> 8);
+        str[2] = static_cast<char>(charcode);
         return 3;
       }
-      str[0] = (uint8_t)(charcode >> 24);
-      str[1] = (uint8_t)(charcode >> 16);
-      str[2] = (uint8_t)(charcode >> 8);
-      str[3] = (uint8_t)charcode;
+      str[0] = static_cast<char>(charcode >> 24);
+      str[1] = static_cast<char>(charcode >> 16);
+      str[2] = static_cast<char>(charcode >> 8);
+      str[3] = static_cast<char>(charcode);
       return 4;
   }
   return 0;
diff --git a/core/fxcrt/cfx_binarybuf.cpp b/core/fxcrt/cfx_binarybuf.cpp
index a1388b8d32..6c67912d3b 100644
--- a/core/fxcrt/cfx_binarybuf.cpp
+++ b/core/fxcrt/cfx_binarybuf.cpp
@@ -51,7 +51,8 @@ void CFX_BinaryBuf::ExpandBuf(FX_STRSIZE add_size) {
   if (m_AllocSize >= new_size.ValueOrDie())
     return;
 
-  int alloc_step = std::max(128, m_AllocStep ? m_AllocStep : m_AllocSize / 4);
+  FX_STRSIZE alloc_step = std::max(static_cast<FX_STRSIZE>(128),
+                                   m_AllocStep ? m_AllocStep : m_AllocSize / 4);
   new_size += alloc_step - 1;  // Quantize, don't combine these lines.
   new_size /= alloc_step;
   new_size *= alloc_step;
diff --git a/core/fxcrt/cfx_seekablestreamproxy.cpp b/core/fxcrt/cfx_seekablestreamproxy.cpp
index da1170717a..a67ec52c85 100644
--- a/core/fxcrt/cfx_seekablestreamproxy.cpp
+++ b/core/fxcrt/cfx_seekablestreamproxy.cpp
@@ -230,15 +230,15 @@ FX_STRSIZE CFX_SeekableStreamProxy::ReadData(uint8_t* pBuffer,
 FX_STRSIZE CFX_SeekableStreamProxy::ReadString(wchar_t* pStr,
                                                FX_STRSIZE iMaxLength,
                                                bool* bEOS) {
-  ASSERT(pStr);
-  ASSERT(iMaxLength > 0);
+  if (!pStr || iMaxLength <= 0)
+    return 0;
 
   if (m_IsWriteStream)
     return 0;
 
   if (m_wCodePage == FX_CODEPAGE_UTF16LE ||
       m_wCodePage == FX_CODEPAGE_UTF16BE) {
-    FX_FILESIZE iBytes = iMaxLength * 2;
+    FX_STRSIZE iBytes = iMaxLength * 2;
     FX_STRSIZE iLen = ReadData(reinterpret_cast<uint8_t*>(pStr), iBytes);
     iMaxLength = iLen / 2;
     if (sizeof(wchar_t) > 2 && iMaxLength > 0)
diff --git a/core/fxcrt/cfx_seekablestreamproxy.h b/core/fxcrt/cfx_seekablestreamproxy.h
index 1a8e6f2f3b..0e427fc79b 100644
--- a/core/fxcrt/cfx_seekablestreamproxy.h
+++ b/core/fxcrt/cfx_seekablestreamproxy.h
@@ -25,7 +25,7 @@ class CFX_SeekableStreamProxy : public CFX_Retainable {
 
   FX_FILESIZE GetLength() const { return m_pStream->GetSize(); }
   FX_FILESIZE GetPosition() { return m_iPosition; }
-  FX_STRSIZE GetBOMLength() const { return std::max(0, m_wBOMLength); }
+  FX_STRSIZE GetBOMLength() const { return m_wBOMLength; }
   bool IsEOF() const { return m_iPosition >= GetLength(); }
 
   void Seek(From eSeek, FX_FILESIZE iOffset);