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>

1 files changed, 2 insertions, 4 deletions

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);