Remove "this==NULL" and adjust corresponding callers

core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp

 // Copyright 2014 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 "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_render.h"
@@ skipping 176 matching lines @@
     pData->m_pPathList[pData->m_PathCount - 1].SetNull();
     FXSYS_memmove32(pData->m_pTypeList + index, pData->m_pTypeList + index + 1, pData->m_PathCount - index - 1);
     pData->m_PathCount --;
 }
 #define FPDF_CLIPPATH_MAX_TEXTS 1024
 void CPDF_ClipPath::AppendTexts(CPDF_TextObject** pTexts, int count)
 {
     CPDF_ClipPathData* pData = GetModify();
     if (pData->m_TextCount + count > FPDF_CLIPPATH_MAX_TEXTS) {
         for (int i = 0; i < count; i ++) {
-            pTexts[i]->Release();
+            if (pTexts[i])
+                pTexts[i]->Release();
         }
         return;
     }
     CPDF_TextObject** pNewList = FX_Alloc(CPDF_TextObject*, pData->m_TextCount + count + 1);
     if (pData->m_pTextList) {
         FXSYS_memcpy32(pNewList, pData->m_pTextList, pData->m_TextCount * sizeof(CPDF_TextObject*));
         FX_Free(pData->m_pTextList);
     }
     pData->m_pTextList = pNewList;
     for (int i = 0; i < count; i ++) {
@@ skipping 266 matching lines @@
     for (FX_DWORD i = 0; i < pArray->GetCount(); i ++) {
         pData->m_DashArray[i] = FXSYS_Mul(pArray->GetNumber(i), scale);
     }
 }
 void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS, CPDF_StreamContentParser* pParser)
 {
     CPDF_GeneralStateData* pGeneralState = m_GeneralState.GetModify();
     FX_POSITION pos = pGS->GetStartPos();
     while (pos) {
         CFX_ByteString key_str;
-        CPDF_Object* pObject = pGS->GetNextElement(pos, key_str)->GetDirect();
+        CPDF_Object* pElement = pGS->GetNextElement(pos, key_str);
+        CPDF_Object* pObject = pElement ? pElement->GetDirect() : NULL;
         if (pObject == NULL) {
             continue;
         }
         FX_DWORD key = key_str.GetID();
         switch (key) {
             case FXBSTR_ID('L', 'W', 0, 0):
                 m_GraphState.GetModify()->m_LineWidth = pObject->GetNumber();
                 break;
             case FXBSTR_ID('L', 'C', 0, 0):
                 m_GraphState.GetModify()->m_LineCap = (CFX_GraphStateData::LineCap)pObject->GetInteger();
@@ skipping 123 matching lines @@
     m_MarkName = src.m_MarkName;
     m_ParamType = src.m_ParamType;
     if (m_ParamType == DirectDict) {
         m_pParam = ((CPDF_Dictionary*)src.m_pParam)->Clone();
     } else {
         m_pParam = src.m_pParam;
     }
 }
 CPDF_ContentMarkItem::~CPDF_ContentMarkItem()
 {
-    if (m_ParamType == DirectDict) {
+    if (m_ParamType == DirectDict && m_pParam) {
         ((CPDF_Dictionary*)m_pParam)->Release();
     }
 }
 FX_BOOL CPDF_ContentMarkItem::HasMCID() const
 {
     if (m_pParam && (m_ParamType == DirectDict || m_ParamType == PropertiesDict)) {
         return ((CPDF_Dictionary *)m_pParam)->KeyExist(FX_BSTRC("MCID"));
     }
     return FALSE;
 }
@@ skipping 59 matching lines @@
             pDict = NULL;
             if (item.GetParamType() == CPDF_ContentMarkItem::PropertiesDict ||
                     item.GetParamType() == CPDF_ContentMarkItem::DirectDict) {
                 pDict = (CPDF_Dictionary*)item.GetParam();
             }
             return TRUE;
         }
     }
     return FALSE;
 }