CPDF_Document::LoadPattern() and friends always have a valid matrix.

core/fpdfapi/fpdf_page/cpdf_shadingpattern.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/fpdf_page/cpdf_shadingpattern.h"
 
 #include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_document.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_object.h"
 
 namespace {
 
 ShadingType ToShadingType(int type) {
   return (type > static_cast<int>(kInvalidShading) &&
           type < static_cast<int>(kMaxShading))
              ? static_cast<ShadingType>(type)
              : kInvalidShading;
 }
 
 }  // namespace
 
 CPDF_ShadingPattern::CPDF_ShadingPattern(CPDF_Document* pDoc,
                                          CPDF_Object* pPatternObj,
                                          FX_BOOL bShading,
-                                         const CFX_Matrix* parentMatrix)
+                                         const CFX_Matrix& parentMatrix)
     : CPDF_Pattern(SHADING,
                    pDoc,
                    bShading ? nullptr : pPatternObj,
                    parentMatrix),
       m_ShadingType(kInvalidShading),
       m_bShadingObj(bShading),
       m_pShadingObj(pPatternObj),
       m_pCS(nullptr),
       m_pCountedCS(nullptr),
       m_nFuncs(0) {
   if (!bShading) {
     CPDF_Dictionary* pDict = m_pPatternObj->GetDict();
     m_Pattern2Form = pDict->GetMatrixBy("Matrix");
     m_pShadingObj = pDict->GetDirectObjectBy("Shading");
-    if (parentMatrix)
-      m_Pattern2Form.Concat(*parentMatrix);
+    m_Pattern2Form.Concat(parentMatrix);
   }
   for (size_t i = 0; i < FX_ArraySize(m_pFunctions); ++i)
     m_pFunctions[i] = nullptr;
 }
 
 CPDF_ShadingPattern::~CPDF_ShadingPattern() {
   for (size_t i = 0; i < m_nFuncs; ++i)
     delete m_pFunctions[i];
 
   CPDF_ColorSpace* pCS = m_pCountedCS ? m_pCountedCS->get() : nullptr;
@@ skipping 37 matching lines @@
     m_pCountedCS = pDocPageData->FindColorSpacePtr(m_pCS->GetArray());
 
   m_ShadingType = ToShadingType(pShadingDict->GetIntegerBy("ShadingType"));
 
   // We expect to have a stream if our shading type is a mesh.
   if (IsMeshShading() && !ToStream(m_pShadingObj))
     return FALSE;
 
   return TRUE;
 }