use same logic in both Creates

Change-Id: I49dab360c5f93e40f5a6e91fbe721935d795472c

vcl/headless/svpbmp.cxx

@@ -121,7 +121,7 @@ BitmapBuffer* ImplCreateDIB(
         pDIB->maPalette.SetEntryCount( nColors );
     }
 
-    size_t size = pDIB->mnScanlineSize * pDIB->mnHeight;
+    const size_t size = pDIB->mnScanlineSize * pDIB->mnHeight;
     if (size > SAL_MAX_INT32)
     {
         delete pDIB;
@@ -176,10 +176,18 @@ bool SvpSalBitmap::Create(const SalBitmap& rBmp)
     {
         // TODO: reference counting...
         mpDIB = new BitmapBuffer( *rSalBmp.mpDIB );
+
+        const size_t size = mpDIB->mnScanlineSize * mpDIB->mnHeight;
+        if (size > SAL_MAX_INT32)
+        {
+            delete mpDIB;
+            mpDIB = nullptr;
+            return false;
+        }
+
         // TODO: get rid of this when BitmapBuffer gets copy constructor
         try
         {
-            size_t size = mpDIB->mnScanlineSize * mpDIB->mnHeight;
             mpDIB->mpBits = new sal_uInt8[size];
             std::memcpy(mpDIB->mpBits, rSalBmp.mpDIB->mpBits, size);
         }