Fix a problem that JP2 image is not displayed because index color space is used

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 "../../../include/fxge/fx_ge.h"
 #include "../../../include/fxcodec/fx_codec.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_render.h"
@@ skipping 487 matching lines @@
 {
     if (m_pColorSpace == NULL) {
         return NULL;
     }
     DIB_COMP_DATA* pCompData = FX_Alloc(DIB_COMP_DATA, m_nComponents);
     if (pCompData == NULL) {
         return NULL;
     }
     int max_data = (1 << m_bpc) - 1;
     CPDF_Array* pDecode = m_pDict->GetArray(FX_BSTRC("Decode"));
+    FX_DWORD arrSize = pDecode ? pDecode->GetCount() : 0;
+    if (arrSize == 0) {
+        return NULL;
+    }
     if (pDecode) {
         for (FX_DWORD i = 0; i < m_nComponents; i ++) {
-            pCompData[i].m_DecodeMin = pDecode->GetNumber(i * 2);
-            FX_FLOAT max = pDecode->GetNumber(i * 2 + 1);
+            pCompData[i].m_DecodeMin = pDecode->GetNumber((i * 2) % arrSize);
+            FX_FLOAT max = pDecode->GetNumber((i * 2 + 1) % arrSize);
             pCompData[i].m_DecodeStep = (max - pCompData[i].m_DecodeMin) / max_data;
             FX_FLOAT def_value, def_min, def_max;
             m_pColorSpace->GetDefaultValue(i, def_value, def_min, def_max);
             if (m_Family == PDFCS_INDEXED) {
                 def_max = (FX_FLOAT)max_data;
             }
             if (def_min != pCompData[i].m_DecodeMin || def_max != max) {
                 bDefaultDecode = FALSE;
             }
         }
@@ skipping 986 matching lines @@
 {
     return ((CPDF_ProgressiveImageLoaderHandle*)LoadHandle)->Continue(pPause);
 }
 CPDF_ImageLoader::~CPDF_ImageLoader()
 {
     if (!m_bCached) {
         delete m_pBitmap;
         delete m_pMask;
     }
 }