RefCount CPDF_TransferFunc all the time.

Prefer internal reference counts over ad-hoc schemes.

Change-Id: I8d420e9e9827ac39fdc0bc8146a532caeee10f26
Reviewed-on: https://pdfium-review.googlesource.com/3615
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/core/fpdfapi/page/cpdf_generalstate.cpp b/core/fpdfapi/page/cpdf_generalstate.cpp
index dd5c5af878..513e5ff7a5 100644
--- a/core/fpdfapi/page/cpdf_generalstate.cpp
+++ b/core/fpdfapi/page/cpdf_generalstate.cpp
@@ -124,12 +124,13 @@ void CPDF_GeneralState::SetTR(CPDF_Object* pObject) {
   m_Ref.GetPrivateCopy()->m_pTR = pObject;
 }
 
-CPDF_TransferFunc* CPDF_GeneralState::GetTransferFunc() const {
+CFX_RetainPtr<CPDF_TransferFunc> CPDF_GeneralState::GetTransferFunc() const {
   const StateData* pData = m_Ref.GetObject();
   return pData ? pData->m_pTransferFunc : nullptr;
 }
 
-void CPDF_GeneralState::SetTransferFunc(CPDF_TransferFunc* pFunc) {
+void CPDF_GeneralState::SetTransferFunc(
+    const CFX_RetainPtr<CPDF_TransferFunc>& pFunc) {
   m_Ref.GetPrivateCopy()->m_pTransferFunc = pFunc;
 }
 
@@ -277,7 +278,9 @@ CPDF_GeneralState::StateData::StateData(const StateData& that)
 CPDF_GeneralState::StateData::~StateData() {
   if (m_pTransferFunc && m_pTransferFunc->m_pPDFDoc) {
     CPDF_DocRenderData* pDocCache = m_pTransferFunc->m_pPDFDoc->GetRenderData();
-    if (pDocCache)
-      pDocCache->ReleaseTransferFunc(m_pTR);
+    if (pDocCache) {
+      m_pTransferFunc.Reset();  // Give up our reference first.
+      pDocCache->MaybePurgeTransferFunc(m_pTR);
+    }
   }
 }