Fix blank page issue caused by too strict correction on bpc

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.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 "../../../../third_party/base/nonstd_unique_ptr.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../../include/fpdfapi/fpdf_render.h"
@@ skipping 939 matching lines @@
   m_bpc = m_bpc_orig;
   CPDF_Object* pFilter = m_pDict->GetElementValue(FX_BSTRC("Filter"));
   if (pFilter) {
     if (pFilter->GetType() == PDFOBJ_NAME) {
       CFX_ByteString filter = pFilter->GetString();
       if (filter == FX_BSTRC("CCITTFaxDecode") ||
           filter == FX_BSTRC("JBIG2Decode")) {
         m_bpc = 1;
         m_nComponents = 1;
       }
-      if (filter == FX_BSTRC("RunLengthDecode") ||
-          filter == FX_BSTRC("DCTDecode")) {
+      if (filter == FX_BSTRC("RunLengthDecode") && m_bpc != 1) {

[Tom Sepez, 2015/09/08 15:47:19]

nit: I might write
   if (filter == FX_BSTRC("RunLengthDecode")) {
      if (m_bpc != 1) {
         m_bpc = 8;
      }
   } else if (filter == FX_BSTRC("DCTDecode) { ...

to avoid a second string comparison when when know the first one matched.

[jun_fang, 2015/09/09 09:57:12]

Acknowledged.

+        m_bpc = 8;
+      }
+      if (filter == FX_BSTRC("DCTDecode")) {
         m_bpc = 8;
       }
     } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
       CPDF_Array* pArray = (CPDF_Array*)pFilter;
       if (pArray->GetString(pArray->GetCount() - 1) ==
               FX_BSTRC("CCITTFaxDecode") ||
           pArray->GetString(pArray->GetCount() - 1) ==
               FX_BSTRC("JBIG2Decode")) {
         m_bpc = 1;
         m_nComponents = 1;
@@ skipping 691 matching lines @@
 }
 FX_BOOL CPDF_ImageLoader::Continue(void* LoadHandle, IFX_Pause* pPause) {
   return ((CPDF_ProgressiveImageLoaderHandle*)LoadHandle)->Continue(pPause);
 }
 CPDF_ImageLoader::~CPDF_ImageLoader() {
   if (!m_bCached) {
     delete m_pBitmap;
     delete m_pMask;
   }
 }