Check that the names buffer is not empty before passing to GetNameFromTT.

core/src/fxge/ge/fx_ge_fontmap.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 <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 1403 matching lines @@
   if (!FXSYS_fread(buffer, 12, 1, pFile)) {
     return;
   }
   FX_DWORD nTables = GET_TT_SHORT(buffer + 4);
   CFX_ByteString tables = FPDF_ReadStringFromFile(pFile, nTables * 16);
   if (tables.IsEmpty()) {
     return;
   }
   CFX_ByteString names =
       FPDF_LoadTableFromTT(pFile, tables, nTables, 0x6e616d65);
+  if (names.IsEmpty()) {
+    return;
+  }
   CFX_ByteString facename = GetNameFromTT(names, 1);
   CFX_ByteString style = GetNameFromTT(names, 2);
   if (style != "Regular") {
     facename += " " + style;
   }
   if (pdfium::ContainsKey(m_FontList, facename))
     return;
 
   CFX_FontFaceInfo* pInfo =
       new CFX_FontFaceInfo(path, facename, tables, offset, filesize);
@@ skipping 159 matching lines @@
 int PDF_GetStandardFontName(CFX_ByteString* name) {
   AltFontName* found = static_cast<AltFontName*>(
       FXSYS_bsearch(name->c_str(), g_AltFontNames, FX_ArraySize(g_AltFontNames),
                     sizeof(AltFontName), CompareString));
   if (!found)
     return -1;
 
   *name = g_Base14FontNames[found->m_Index];
   return found->m_Index;
 }