Fix a crash when parsing truetype fonts without any tables.

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 "../../../include/fxge/fx_ge.h"
 #include "../../../include/fxge/fx_freetype.h"
 #include "text_int.h"
 #define GET_TT_SHORT(w)  (FX_WORD)(((w)[0] << 8) | (w)[1])
@@ skipping 1410 matching lines @@
 }
 void CFX_FolderFontInfo::ReportFace(CFX_ByteString& path, FXSYS_FILE* pFile, FX_DWORD filesize, FX_DWORD offset)
 {
     FXSYS_fseek(pFile, offset, FXSYS_SEEK_SET);
     char buffer[16];
     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);
     CFX_ByteString facename = _FPDF_GetNameFromTT(names, 1);
     CFX_ByteString style = _FPDF_GetNameFromTT(names, 2);
     if (style != "Regular") {
         facename += " " + style;
     }
     FX_LPVOID p;
     if (m_FontList.Lookup(facename, p)) {
         return;
     }
@@ skipping 108 matching lines @@
     }
     CFontFaceInfo* pFont = (CFontFaceInfo*)hFont;
     name = pFont->m_FaceName;
     return TRUE;
 }
 FX_BOOL CFX_FolderFontInfo::GetFontCharset(void* hFont, int& charset)
 {
     return FALSE;
 }
 #endif