Fix a leak with FPDFPageObj_NewImgeObj().

core/fpdfapi/fpdf_page/fpdf_page_doc.cpp

Index: core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
diff --git a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 059679a8cda1f3d7284c6278e73b074697a2b9b7..f9eae859758a41f73469a6afa638b3cb44e3badb 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -439,6 +439,18 @@ void CPDF_DocPageData::ReleaseImage(const CPDF_Object* pImageStream) {
   m_ImageMap.erase(it);
 }
 
+bool CPDF_DocPageData::HasImage(const CPDF_Object* pImageStream) const {

[Wei Li, 2016/08/04 18:00:39]

Why adding an extra function which does the same as the first half of
ReleaseImage()?

[Lei Zhang, 2016/08/04 21:58:25]

CPDF_ImageObject needs to know if CPDF_ImageObject is the owner of the
CPDF_Image, and only call ReleaseImage() if this returns true.

[Wei Li, 2016/08/04 23:36:39]

I think you may keep the change of patch 1 and let ReleaseImage() returns true
only when it is found in |m_ImageMap|. In this way, the same checking logic will
run only once.

+  if (!pImageStream)
+    return false;
+
+  uint32_t dwObjNum = pImageStream->GetObjNum();
+  if (!dwObjNum)
+    return false;
+
+  auto it = m_ImageMap.find(dwObjNum);
+  return it != m_ImageMap.end() && it->second;
+}
+
 CPDF_IccProfile* CPDF_DocPageData::GetIccProfile(
     CPDF_Stream* pIccProfileStream) {
   if (!pIccProfileStream)