Fix uninitialized triangle in rendering.

core/src/fpdfapi/fpdf_render/fpdf_render_pattern.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_render.h"
 #include "../../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../../include/fxge/fx_ge.h"
 #include "../fpdf_page/pageint.h"
@@ skipping 371 matching lines @@
 {
     ASSERT(pBitmap->GetFormat() == FXDIB_Argb);
     if (pShadingStream->GetType() != PDFOBJ_STREAM) {
         return;
     }
     CPDF_MeshStream stream;
     if (!stream.Load(pShadingStream, pFuncs, nFuncs, pCS)) {
         return;
     }
     CPDF_MeshVertex triangle[3];
+    FXSYS_memset32(triangle, 0, sizeof(triangle));
+
     while (!stream.m_BitStream.IsEOF()) {
         CPDF_MeshVertex vertex;
         FX_DWORD flag = stream.GetVertex(vertex, pObject2Bitmap);
         if (flag == 0) {
             triangle[0] = vertex;
             for (int j = 1; j < 3; j ++) {
                 stream.GetVertex(triangle[j], pObject2Bitmap);
             }
         } else {
             if (flag == 1) {
@@ skipping 682 matching lines @@
             bStroke = FALSE;
             bPattern = TRUE;
         }
     }
 #ifdef _FPDFAPI_MINI_
     if (bPattern && m_DitherBits) {
         DitherObjectArea(pPathObj, pObj2Device);
     }
 #endif
 }