Revert "Remove FX_Alloc() null checks now that it can't return NULL."

core/src/fpdftext/fpdf_text_int.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_resource.h"
 #include "../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../include/fpdftext/fpdf_text.h"
 #include "../../include/fpdfapi/fpdf_page.h"
@@ skipping 1146 matching lines @@
 {
     PAGECHAR_INFO Info = *(PAGECHAR_INFO*)m_TempCharList.GetAt(i);
     FX_WCHAR wChar = str.GetAt(i);
     if(!IsControlChar(&Info)) {
         Info.m_Index = m_TextBuf.GetLength();
         if (wChar >= 0xFB00 && wChar <= 0xFB06) {
             FX_LPWSTR pDst = NULL;
             FX_STRSIZE nCount = FX_Unicode_GetNormalization(wChar, pDst);
             if (nCount >= 1) {
                 pDst = FX_Alloc(FX_WCHAR, nCount);
+                if (!pDst) {
+                    return;
+                }
                 FX_Unicode_GetNormalization(wChar, pDst);
                 for (int nIndex = 0; nIndex < nCount; nIndex++) {
                     PAGECHAR_INFO Info2 = Info;
                     Info2.m_Unicode = pDst[nIndex];
                     Info2.m_Flag = FPDFTEXT_CHAR_PIECE;
                     m_TextBuf.AppendChar(Info2.m_Unicode);
                     if( !m_ParseOptions.m_bGetCharCodeOnly) {
                         m_charList.Add(Info2);
                     }
                 }
@@ skipping 12 matching lines @@
 void CPDF_TextPage::AddCharInfoByRLDirection(CFX_WideString& str, int i)
 {
     PAGECHAR_INFO Info = *(PAGECHAR_INFO*)m_TempCharList.GetAt(i);
     if(!IsControlChar(&Info)) {
         Info.m_Index = m_TextBuf.GetLength();
         FX_WCHAR wChar = FX_GetMirrorChar(str.GetAt(i), TRUE, FALSE);
         FX_LPWSTR pDst = NULL;
         FX_STRSIZE nCount = FX_Unicode_GetNormalization(wChar, pDst);
         if (nCount >= 1) {
             pDst = FX_Alloc(FX_WCHAR, nCount);
+            if (!pDst) {
+                return;
+            }
             FX_Unicode_GetNormalization(wChar, pDst);
             for (int nIndex = 0; nIndex < nCount; nIndex++) {
                 PAGECHAR_INFO Info2 = Info;
                 Info2.m_Unicode = pDst[nIndex];
                 Info2.m_Flag = FPDFTEXT_CHAR_PIECE;
                 m_TextBuf.AppendChar(Info2.m_Unicode);
                 if( !m_ParseOptions.m_bGetCharCodeOnly) {
                     m_charList.Add(Info2);
                 }
             }
@@ skipping 1622 matching lines @@
     if (!m_IsParserd || index < 0 || index >= m_LinkList.GetSize()) {
         return;
     }
     CPDF_LinkExt* link = NULL;
     link = m_LinkList.GetAt(index);
     if (!link) {
         return ;
     }
     m_pTextPage->GetRectArray(link->m_Start, link->m_Count, rects);
 }