Fix memory leak in cmap parsing

core/fpdfapi/fpdf_font/fpdf_font_cid.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 "core/fpdfapi/fpdf_font/font_int.h"
 
 #include "core/fpdfapi/fpdf_cmaps/cmap_int.h"
 #include "core/fpdfapi/fpdf_font/ttgsubtable.h"
@@ skipping 395 matching lines @@
     m_Status = 0;
   } else if (m_Status == 6) {
     m_pCMap->m_bVertical = CMap_GetCode(word) != 0;
     m_Status = 0;
   } else if (m_Status == 7) {
     if (word == "endcodespacerange") {
       int nSegs = m_CodeRanges.GetSize();
       if (nSegs > 1) {
         m_pCMap->m_CodingScheme = CPDF_CMap::MixedFourBytes;
         m_pCMap->m_nCodeRanges = nSegs;
+        FX_Free(m_pCMap->m_pLeadingBytes);
         m_pCMap->m_pLeadingBytes =
             FX_Alloc2D(uint8_t, nSegs, sizeof(CMap_CodeRange));
         FXSYS_memcpy(m_pCMap->m_pLeadingBytes, m_CodeRanges.GetData(),
                      nSegs * sizeof(CMap_CodeRange));
       } else if (nSegs == 1) {
         m_pCMap->m_CodingScheme = (m_CodeRanges[0].m_CharSize == 2)
                                       ? CPDF_CMap::TwoBytes
                                       : CPDF_CMap::OneByte;
       }
       m_Status = 0;
@@ skipping 354 matching lines @@
   m_EmbeddedCount = pFontGlobals->m_EmbeddedToUnicodes[charset].m_Count;
 }
 
 CIDSet CharsetFromOrdering(const CFX_ByteStringC& ordering) {
   for (size_t charset = 1; charset < FX_ArraySize(g_CharsetNames); ++charset) {
     if (ordering == g_CharsetNames[charset])
       return CIDSetFromSizeT(charset);
   }
   return CIDSET_UNKNOWN;
 }