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

core/src/fxge/win32/fx_win32_dib.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"
 #if _FX_OS_ == _FX_WIN32_DESKTOP_ ||  _FX_OS_ == _FX_WIN64_
 #include <windows.h>
 #include "../../../include/fxge/fx_ge_win32.h"
@@ skipping 51 matching lines @@
     CFX_DIBitmap* pBitmap = new CFX_DIBitmap;
     FXDIB_Format format = bAlpha ? (FXDIB_Format)(pbmi->bmiHeader.biBitCount + 0x200) : (FXDIB_Format)pbmi->bmiHeader.biBitCount;
     FX_BOOL ret = pBitmap->Create(width, height, format);
     if (!ret) {
         delete pBitmap;
         return NULL;
     }
     FXSYS_memcpy32(pBitmap->GetBuffer(), pData, pitch * height);
     if (bBottomUp) {
         FX_LPBYTE temp_buf = FX_Alloc(FX_BYTE, pitch);
+        if (!temp_buf) {
+            if (pBitmap) {
+                delete pBitmap;
+            }
+            return NULL;
+        }
         int top = 0, bottom = height - 1;
         while (top < bottom) {
             FXSYS_memcpy32(temp_buf, pBitmap->GetBuffer() + top * pitch, pitch);
             FXSYS_memcpy32(pBitmap->GetBuffer() + top * pitch, pBitmap->GetBuffer() + bottom * pitch, pitch);
             FXSYS_memcpy32(pBitmap->GetBuffer() + bottom * pitch, temp_buf, pitch);
             top ++;
             bottom --;
         }
         FX_Free(temp_buf);
         temp_buf = NULL;
@@ skipping 108 matching lines @@
     bmih.biHeight = -height;
     bmih.biCompression = BI_RGB;
     CFX_DIBitmap* pDIBitmap = new CFX_DIBitmap;
     int ret = 0;
     if (bmih.biBitCount == 1 || bmih.biBitCount == 8) {
         int size = sizeof (BITMAPINFOHEADER) + 8;
         if (bmih.biBitCount == 8) {
             size += sizeof (FX_DWORD) * 254;
         }
         BITMAPINFO* pbmih = (BITMAPINFO*)FX_Alloc(FX_BYTE, size);
+        if (!pbmih) {
+            delete pDIBitmap;
+            if (bCreatedDC) {
+                DeleteDC(hDC);
+            }
+            return NULL;
+        }
         pbmih->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
         pbmih->bmiHeader.biBitCount = bmih.biBitCount;
         pbmih->bmiHeader.biCompression = BI_RGB;
         pbmih->bmiHeader.biHeight = -height;
         pbmih->bmiHeader.biPlanes = 1;
         pbmih->bmiHeader.biWidth = bmih.biWidth;
         if (!pDIBitmap->Create(bmih.biWidth, height, bmih.biBitCount == 1 ? FXDIB_1bppRgb : FXDIB_8bppRgb)) {
             delete pDIBitmap;
             FX_Free(pbmih);
             if (bCreatedDC) {
@@ skipping 63 matching lines @@
 }
 void CFX_WindowsDIB::LoadFromDevice(HDC hDC, int left, int top)
 {
     ::BitBlt(m_hMemDC, 0, 0, m_Width, m_Height, hDC, left, top, SRCCOPY);
 }
 void CFX_WindowsDIB::SetToDevice(HDC hDC, int left, int top)
 {
     ::BitBlt(hDC, left, top, m_Width, m_Height, m_hMemDC, 0, 0, SRCCOPY);
 }
 #endif