Remove support for negative params to ReleaseBuffer()

This CL removes the default param value for this method, which was
negative. It also adds in a method to get buffer lengths, so that the
callsites can explictly passing in the length of the buffer if they
were using the default value previously.

BUG=pdfium:828

Change-Id: I0170771ee81970b8b601631015ab3e6e39fea8ea
Reviewed-on: https://pdfium-review.googlesource.com/9790
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

8 files changed, 18 insertions, 16 deletions

diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 7025b3e7d8..8323426e74 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -147,7 +147,7 @@ CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
     }
   }
   dest_buf[dest_len] = 0;
-  res.ReleaseBuffer();
+  res.ReleaseBuffer(res.GetStringLength());
   return res;
 }
 
diff --git a/core/fpdftext/cpdf_textpagefind.cpp b/core/fpdftext/cpdf_textpagefind.cpp
index adef9f6c0c..3c8e532a7f 100644
--- a/core/fpdftext/cpdf_textpagefind.cpp
+++ b/core/fpdftext/cpdf_textpagefind.cpp
@@ -377,7 +377,7 @@ bool CPDF_TextPageFind::ExtractSubString(CFX_WideString& rString,
                      : (int)FXSYS_wcslen(lpszFullString);
   ASSERT(nLen >= 0);
   memcpy(rString.GetBuffer(nLen), lpszFullString, nLen * sizeof(wchar_t));
-  rString.ReleaseBuffer();
+  rString.ReleaseBuffer(rString.GetStringLength());
   return true;
 }
 
diff --git a/core/fxcrt/cfx_bytestring.cpp b/core/fxcrt/cfx_bytestring.cpp
index 6e01933682..5dcaf613a0 100644
--- a/core/fxcrt/cfx_bytestring.cpp
+++ b/core/fxcrt/cfx_bytestring.cpp
@@ -361,12 +361,10 @@ void CFX_ByteString::AllocBeforeWrite(FX_STRSIZE nNewLength) {
 }
 
 void CFX_ByteString::ReleaseBuffer(FX_STRSIZE nNewLength) {
+  ASSERT(nNewLength >= 0);
   if (!m_pData)
     return;
 
-  if (nNewLength == -1)
-    nNewLength = FXSYS_strlen(m_pData->m_String);
-
   nNewLength = std::min(nNewLength, m_pData->m_nAllocLength);
   if (nNewLength == 0) {
     clear();
@@ -507,7 +505,7 @@ void CFX_ByteString::FormatV(const char* pFormat, va_list argList) {
       // a terminating NUL that's not included in nMaxLen.
       memset(m_pData->m_String, 0, nMaxLen + 1);
       vsnprintf(m_pData->m_String, nMaxLen + 1, pFormat, argListSave);
-      ReleaseBuffer();
+      ReleaseBuffer(GetStringLength());
     }
   }
   va_end(argListSave);
diff --git a/core/fxcrt/cfx_bytestring.h b/core/fxcrt/cfx_bytestring.h
index 519cee39d4..8bd9f39fc0 100644
--- a/core/fxcrt/cfx_bytestring.h
+++ b/core/fxcrt/cfx_bytestring.h
@@ -79,6 +79,9 @@ class CFX_ByteString {
   }
 
   FX_STRSIZE GetLength() const { return m_pData ? m_pData->m_nDataLength : 0; }
+  FX_STRSIZE GetStringLength() const {
+    return m_pData ? FXSYS_strlen(m_pData->m_String) : 0;
+  }
   bool IsEmpty() const { return !GetLength(); }
 
   int Compare(const CFX_ByteStringC& str) const;
@@ -122,7 +125,7 @@ class CFX_ByteString {
 
   void Reserve(FX_STRSIZE len);
   char* GetBuffer(FX_STRSIZE len);
-  void ReleaseBuffer(FX_STRSIZE len = -1);
+  void ReleaseBuffer(FX_STRSIZE len);
 
   CFX_ByteString Mid(FX_STRSIZE first, FX_STRSIZE count) const;
   CFX_ByteString Left(FX_STRSIZE count) const;
diff --git a/core/fxcrt/cfx_bytestring_unittest.cpp b/core/fxcrt/cfx_bytestring_unittest.cpp
index d7f265e32a..4379519046 100644
--- a/core/fxcrt/cfx_bytestring_unittest.cpp
+++ b/core/fxcrt/cfx_bytestring_unittest.cpp
@@ -653,7 +653,7 @@ TEST(fxcrt, ByteStringGetBuffer) {
     char* buffer = str.GetBuffer(12);
     // NOLINTNEXTLINE(runtime/printf)
     strcpy(buffer, "clams");
-    str.ReleaseBuffer();
+    str.ReleaseBuffer(str.GetStringLength());
     EXPECT_EQ("clams", str);
   }
   {
@@ -661,7 +661,7 @@ TEST(fxcrt, ByteStringGetBuffer) {
     char* buffer = str.GetBuffer(12);
     // NOLINTNEXTLINE(runtime/printf)
     strcpy(buffer + 2, "ams");
-    str.ReleaseBuffer();
+    str.ReleaseBuffer(str.GetStringLength());
     EXPECT_EQ("clams", str);
   }
 }
diff --git a/core/fxcrt/cfx_widestring.cpp b/core/fxcrt/cfx_widestring.cpp
index 8937783863..b83752369b 100644
--- a/core/fxcrt/cfx_widestring.cpp
+++ b/core/fxcrt/cfx_widestring.cpp
@@ -488,12 +488,10 @@ void CFX_WideString::AllocBeforeWrite(FX_STRSIZE nNewLength) {
 }
 
 void CFX_WideString::ReleaseBuffer(FX_STRSIZE nNewLength) {
+  ASSERT(nNewLength >= 0);
   if (!m_pData)
     return;
 
-  if (nNewLength == -1)
-    nNewLength = FXSYS_wcslen(m_pData->m_String);
-
   nNewLength = std::min(nNewLength, m_pData->m_nAllocLength);
   if (nNewLength == 0) {
     clear();
@@ -651,7 +649,7 @@ bool CFX_WideString::TryVSWPrintf(FX_STRSIZE size,
   memset(m_pData->m_String, 0, (size + 1) * sizeof(wchar_t));
   int ret = vswprintf(m_pData->m_String, size + 1, pFormat, argList);
   bool bSufficientBuffer = ret >= 0 || m_pData->m_String[size - 1] == 0;
-  ReleaseBuffer();
+  ReleaseBuffer(GetStringLength());
   return bSufficientBuffer;
 }
 
diff --git a/core/fxcrt/cfx_widestring.h b/core/fxcrt/cfx_widestring.h
index 938b1e7958..02045c5c09 100644
--- a/core/fxcrt/cfx_widestring.h
+++ b/core/fxcrt/cfx_widestring.h
@@ -75,6 +75,9 @@ class CFX_WideString {
   void clear() { m_pData.Reset(); }
 
   FX_STRSIZE GetLength() const { return m_pData ? m_pData->m_nDataLength : 0; }
+  FX_STRSIZE GetStringLength() const {
+    return m_pData ? FXSYS_wcslen(m_pData->m_String) : 0;
+  }
   bool IsEmpty() const { return !GetLength(); }
 
   const CFX_WideString& operator=(const wchar_t* str);
@@ -135,7 +138,7 @@ class CFX_WideString {
 
   void Reserve(FX_STRSIZE len);
   wchar_t* GetBuffer(FX_STRSIZE len);
-  void ReleaseBuffer(FX_STRSIZE len = -1);
+  void ReleaseBuffer(FX_STRSIZE len);
 
   int GetInteger() const;
   float GetFloat() const;
diff --git a/core/fxcrt/cfx_widestring_unittest.cpp b/core/fxcrt/cfx_widestring_unittest.cpp
index a53e9a35e2..b743a17fd1 100644
--- a/core/fxcrt/cfx_widestring_unittest.cpp
+++ b/core/fxcrt/cfx_widestring_unittest.cpp
@@ -618,14 +618,14 @@ TEST(fxcrt, WideStringGetBuffer) {
     CFX_WideString str;
     wchar_t* buffer = str.GetBuffer(12);
     wcscpy(buffer, L"clams");
-    str.ReleaseBuffer();
+    str.ReleaseBuffer(str.GetStringLength());
     EXPECT_EQ(L"clams", str);
   }
   {
     CFX_WideString str(L"cl");
     wchar_t* buffer = str.GetBuffer(12);
     wcscpy(buffer + 2, L"ams");
-    str.ReleaseBuffer();
+    str.ReleaseBuffer(str.GetStringLength());
     EXPECT_EQ(L"clams", str);
   }
 }