Get rid of a few |new|s in CPDF_Document.

The chain of destructors may attempt to use m_pDocPage
after it has been set to null by the unique_ptr destructor.
Verify it is still present before using it from any code
that may be called from some other CPDF_ destructor.

Change-Id: I007160231d73feed85d90efc687d6da993653f96
Reviewed-on: https://pdfium-review.googlesource.com/4499
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

7 files changed, 35 insertions, 20 deletions

diff --git a/core/fpdfapi/font/cpdf_font.cpp b/core/fpdfapi/font/cpdf_font.cpp
index b9be3aa868..53186daec6 100644
--- a/core/fpdfapi/font/cpdf_font.cpp
+++ b/core/fpdfapi/font/cpdf_font.cpp
@@ -61,8 +61,11 @@ CPDF_Font::CPDF_Font()
 
 CPDF_Font::~CPDF_Font() {
   if (m_pFontFile) {
-    m_pDocument->GetPageData()->MaybePurgeFontFileStreamAcc(
-        m_pFontFile->GetStream()->AsStream());
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData) {
+      pPageData->MaybePurgeFontFileStreamAcc(
+          m_pFontFile->GetStream()->AsStream());
+    }
   }
 }
 
diff --git a/core/fpdfapi/page/cpdf_color.cpp b/core/fpdfapi/page/cpdf_color.cpp
index f0e433c243..59ce6dab28 100644
--- a/core/fpdfapi/page/cpdf_color.cpp
+++ b/core/fpdfapi/page/cpdf_color.cpp
@@ -42,10 +42,13 @@ void CPDF_Color::ReleaseBuffer() {
 }
 
 void CPDF_Color::ReleaseColorSpace() {
-  if (m_pCS && m_pCS->m_pDocument) {
-    m_pCS->m_pDocument->GetPageData()->ReleaseColorSpace(m_pCS->GetArray());
-    m_pCS = nullptr;
-  }
+  if (!m_pCS || !m_pCS->m_pDocument)
+    return;
+
+  auto* pPageData = m_pCS->m_pDocument->GetPageData();
+  if (pPageData)
+    pPageData->ReleaseColorSpace(m_pCS->GetArray());
+  m_pCS = nullptr;
 }
 
 void CPDF_Color::SetColorSpace(CPDF_ColorSpace* pCS) {
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 400b7a9150..111d45f17e 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -852,7 +852,9 @@ CPDF_ICCBasedCS::~CPDF_ICCBasedCS() {
   if (m_pProfile && m_pDocument) {
     CPDF_Stream* pStream = m_pProfile->GetStream();
     m_pProfile.Reset();  // Give up our reference first.
-    m_pDocument->GetPageData()->MaybePurgeIccProfile(pStream);
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData)
+      pPageData->MaybePurgeIccProfile(pStream);
   }
 }
 
@@ -1049,7 +1051,9 @@ CPDF_IndexedCS::~CPDF_IndexedCS() {
   FX_Free(m_pCompMinMax);
   CPDF_ColorSpace* pCS = m_pCountedBaseCS ? m_pCountedBaseCS->get() : nullptr;
   if (pCS && m_pDocument) {
-    m_pDocument->GetPageData()->ReleaseColorSpace(pCS->GetArray());
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData)
+      pPageData->ReleaseColorSpace(pCS->GetArray());
   }
 }
 
@@ -1132,7 +1136,9 @@ CPDF_PatternCS::CPDF_PatternCS(CPDF_Document* pDoc)
 CPDF_PatternCS::~CPDF_PatternCS() {
   CPDF_ColorSpace* pCS = m_pCountedBaseCS ? m_pCountedBaseCS->get() : nullptr;
   if (pCS && m_pDocument) {
-    m_pDocument->GetPageData()->ReleaseColorSpace(pCS->GetArray());
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData)
+      pPageData->ReleaseColorSpace(pCS->GetArray());
   }
 }
 
diff --git a/core/fpdfapi/page/cpdf_shadingpattern.cpp b/core/fpdfapi/page/cpdf_shadingpattern.cpp
index e19ffaf0c4..133d32ff3a 100644
--- a/core/fpdfapi/page/cpdf_shadingpattern.cpp
+++ b/core/fpdfapi/page/cpdf_shadingpattern.cpp
@@ -50,8 +50,11 @@ CPDF_ShadingPattern::CPDF_ShadingPattern(CPDF_Document* pDoc,
 
 CPDF_ShadingPattern::~CPDF_ShadingPattern() {
   CPDF_ColorSpace* pCS = m_pCountedCS ? m_pCountedCS->get() : nullptr;
-  if (pCS && m_pDocument)
-    m_pDocument->GetPageData()->ReleaseColorSpace(pCS->GetArray());
+  if (pCS && m_pDocument) {
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData)
+      pPageData->ReleaseColorSpace(pCS->GetArray());
+  }
 }
 
 CPDF_TilingPattern* CPDF_ShadingPattern::AsTilingPattern() {
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index c23637e8fa..48791262ea 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -348,14 +348,13 @@ CPDF_Document::CPDF_Document(std::unique_ptr<CPDF_Parser> pParser)
       m_bLinearized(false),
       m_iFirstPageNo(0),
       m_dwFirstPageObjNum(0),
-      m_pDocPage(new CPDF_DocPageData(this)),
-      m_pDocRender(new CPDF_DocRenderData(this)) {
+      m_pDocPage(pdfium::MakeUnique<CPDF_DocPageData>(this)),
+      m_pDocRender(pdfium::MakeUnique<CPDF_DocRenderData>(this)) {
   if (pParser)
     SetLastObjNum(m_pParser->GetLastObjNum());
 }
 
 CPDF_Document::~CPDF_Document() {
-  delete m_pDocPage;
   CPDF_ModuleMgr::Get()->GetPageModule()->ClearStockFont(this);
 }
 
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index 8d3525419f..2f54ba7c28 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -58,7 +58,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   CPDF_Dictionary* GetPage(int iPage);
   int GetPageIndex(uint32_t objnum);
   uint32_t GetUserPermissions() const;
-  CPDF_DocPageData* GetPageData() const { return m_pDocPage; }
+  CPDF_DocPageData* GetPageData() const { return m_pDocPage.get(); }
 
   void SetPageObjNum(int iPage, uint32_t objNum);
 
@@ -142,8 +142,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   bool m_bLinearized;
   int m_iFirstPageNo;
   uint32_t m_dwFirstPageObjNum;
-  // TODO(thestig): Figure out why this cannot be a std::unique_ptr.
-  CPDF_DocPageData* m_pDocPage;
+  std::unique_ptr<CPDF_DocPageData> m_pDocPage;
   std::unique_ptr<CPDF_DocRenderData> m_pDocRender;
   std::unique_ptr<JBig2_DocumentContext> m_pCodecContext;
   std::unique_ptr<CPDF_LinkList> m_pLinksContext;
diff --git a/core/fpdfapi/render/cpdf_dibsource.cpp b/core/fpdfapi/render/cpdf_dibsource.cpp
index e60d0329d0..3e00c8a23c 100644
--- a/core/fpdfapi/render/cpdf_dibsource.cpp
+++ b/core/fpdfapi/render/cpdf_dibsource.cpp
@@ -131,9 +131,11 @@ CPDF_DIBSource::~CPDF_DIBSource() {
   FX_Free(m_pLineBuf);
   m_pCachedBitmap.Reset();  // TODO(tsepez): determine if required early here.
   FX_Free(m_pCompData);
-  CPDF_ColorSpace* pCS = m_pColorSpace;
-  if (pCS && m_pDocument)
-    m_pDocument->GetPageData()->ReleaseColorSpace(pCS->GetArray());
+  if (m_pColorSpace && m_pDocument) {
+    auto* pPageData = m_pDocument->GetPageData();
+    if (pPageData)
+      pPageData->ReleaseColorSpace(m_pColorSpace->GetArray());
+  }
 }
 
 bool CPDF_DIBSource::Load(CPDF_Document* pDoc, const CPDF_Stream* pStream) {