Remove "this==NULL" and adjust corresponding callers

core/src/fpdfapi/fpdf_parser/fpdf_parser_filters.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 "../../fx_zlib.h"
 #include "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fxcodec/fx_codec.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
@@ skipping 58 matching lines @@
 CFX_DataFilter* FPDF_CreateFilter(FX_BSTR name, const CPDF_Dictionary* pParam, int width, int height)
 {
     FX_DWORD id = name.GetID();
     switch (id) {
         case FXBSTR_ID('F', 'l', 'a', 't'):
         case FXBSTR_ID('F', 'l', 0, 0):
         case FXBSTR_ID('L', 'Z', 'W', 'D'):
         case FXBSTR_ID('L', 'Z', 'W', 0): {
                 CFX_DataFilter* pFilter;
                 if (id == FXBSTR_ID('L', 'Z', 'W', 'D') || id == FXBSTR_ID('L', 'Z', 'W', 0)) {
-                    pFilter = FX_NEW CPDF_LzwFilter(pParam->GetInteger("EarlyChange", 1));
+                    pFilter = FX_NEW CPDF_LzwFilter(pParam ? pParam->GetInteger("EarlyChange", 1) : 1);
                 } else {
                     pFilter = FX_NEW CPDF_FlateFilter;
                 }
-                if (pParam->GetInteger("Predictor", 1) > 1) {
+                if ((pParam ? pParam->GetInteger("Predictor", 1) : 1) > 1) {
                     CFX_DataFilter* pPredictor = FX_NEW CPDF_PredictorFilter(pParam->GetInteger(FX_BSTRC("Predictor"), 1),
                                                  pParam->GetInteger(FX_BSTRC("Colors"), 1), pParam->GetInteger(FX_BSTRC("BitsPerComponent"), 8),
                                                  pParam->GetInteger(FX_BSTRC("Columns"), 1));
                     pFilter->SetDestFilter(pPredictor);
                 }
                 return pFilter;
             }
         case FXBSTR_ID('A', 'S', 'C', 'I'):
             if (name == "ASCIIHexDecode") {
                 return FX_NEW CPDF_AsciiHexFilter;
@@ skipping 806 matching lines @@
     }
     if (m_bEndOfLine)
         if (!_FaxSkipEOL(src_buf, bitsize, bitpos)) {
             return FALSE;
         }
     if (m_bByteAlign) {
         bitpos = (bitpos + 7) / 8 * 8;
     }
     return TRUE;
 }