cid#1596254 Null pointer dereferences in GetSotStorageStream

Re-arrange the calling convention to make it obvious that
a valid stream is the same as a good (true) result.

Change-Id: I974b023a8e7231e70ab649628fdbe43c33001e5b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165874
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

5 files changed, 19 insertions, 24 deletions

diff --git a/sc/source/ui/app/transobj.cxx b/sc/source/ui/app/transobj.cxx
index 5d5cd26090c8..1a97a01d049b 100644
--- a/sc/source/ui/app/transobj.cxx
+++ b/sc/source/ui/app/transobj.cxx
@@ -497,8 +497,8 @@ bool ScTransferObj::WriteObject( SvStream& rOStm, void* pUserObject, sal_uInt32
                     uno::Reference<datatransfer::XTransferable> xEditTrans = pEngine->CreateTransferable( aSel );
                     TransferableDataHelper aEditHelper( xEditTrans );
 
-                    std::unique_ptr<SvStream> xStrm;
-                    bRet = aEditHelper.GetSotStorageStream( rFlavor, xStrm );
+                    std::unique_ptr<SvStream> xStrm = aEditHelper.GetSotStorageStream( rFlavor );
+                    bRet = bool(xStrm);
                     rOStm.WriteStream(*xStrm);
                 }
             }
diff --git a/sc/source/ui/view/gridwin.cxx b/sc/source/ui/view/gridwin.cxx
index 35e36339edc1..1b7c16f1884b 100644
--- a/sc/source/ui/view/gridwin.cxx
+++ b/sc/source/ui/view/gridwin.cxx
@@ -4371,7 +4371,7 @@ static SotClipboardFormatId lcl_GetDropFormatId( const uno::Reference<datatransf
         std::unique_ptr<SvStream> xStm;
         TransferableObjectDescriptor aObjDesc;
         if( aDataHelper.GetTransferableObjectDescriptor( SotClipboardFormatId::OBJECTDESCRIPTOR, aObjDesc ) &&
-            aDataHelper.GetSotStorageStream( SotClipboardFormatId::EMBED_SOURCE, xStm ) )
+            (xStm = aDataHelper.GetSotStorageStream( SotClipboardFormatId::EMBED_SOURCE )) )
         {
             bDoRtf = ( ( aObjDesc.maClassName == SvGlobalName( SO3_SW_CLASSID ) ||
                          aObjDesc.maClassName == SvGlobalName( SO3_SWWEB_CLASSID ) )
diff --git a/sc/source/ui/view/viewfun3.cxx b/sc/source/ui/view/viewfun3.cxx
index 07a9205fc427..ee2cccf72f35 100644
--- a/sc/source/ui/view/viewfun3.cxx
+++ b/sc/source/ui/view/viewfun3.cxx
@@ -776,22 +776,20 @@ bool ScViewFunc::PasteOnDrawObjectLinked(
 
     if ( aDataHelper.HasFormat( SotClipboardFormatId::SVXB ) )
     {
-        std::unique_ptr<SvStream> xStm;
-        ScDrawView* pScDrawView = GetScDrawView();
-
-        if( pScDrawView && aDataHelper.GetSotStorageStream( SotClipboardFormatId::SVXB, xStm ) )
-        {
-            Graphic aGraphic;
-            TypeSerializer aSerializer(*xStm);
-            aSerializer.readGraphic(aGraphic);
+        if (ScDrawView* pScDrawView = GetScDrawView())
+            if (std::unique_ptr<SvStream> xStm = aDataHelper.GetSotStorageStream( SotClipboardFormatId::SVXB ) )
+            {
+                Graphic aGraphic;
+                TypeSerializer aSerializer(*xStm);
+                aSerializer.readGraphic(aGraphic);
 
-            const OUString aBeginUndo(ScResId(STR_UNDO_DRAGDROP));
+                const OUString aBeginUndo(ScResId(STR_UNDO_DRAGDROP));
 
-            if(pScDrawView->ApplyGraphicToObject( rHitObj, aGraphic, aBeginUndo, "" ))
-            {
-                return true;
+                if(pScDrawView->ApplyGraphicToObject( rHitObj, aGraphic, aBeginUndo, "" ))
+                {
+                    return true;
+                }
             }
-        }
     }
     else if ( aDataHelper.HasFormat( SotClipboardFormatId::GDIMETAFILE ) )
     {
diff --git a/sc/source/ui/view/viewfun4.cxx b/sc/source/ui/view/viewfun4.cxx
index 339cff8978dd..fc7da221eae7 100644
--- a/sc/source/ui/view/viewfun4.cxx
+++ b/sc/source/ui/view/viewfun4.cxx
@@ -162,12 +162,12 @@ void ScViewFunc::PasteRTF( SCCOL nStartCol, SCROW nStartRow,
 
         OUString aStr;
         std::unique_ptr<SvStream> xStream;
-        if ( aDataHelper.GetSotStorageStream( SotClipboardFormatId::RTF, xStream ) && xStream )
+        if ( (xStream = aDataHelper.GetSotStorageStream( SotClipboardFormatId::RTF )) )
             // mba: clipboard always must contain absolute URLs (could be from alien source)
             aImpEx.ImportStream( *xStream, OUString(), SotClipboardFormatId::RTF );
         else if ( aDataHelper.GetString( SotClipboardFormatId::RTF, aStr ) )
             aImpEx.ImportString( aStr, SotClipboardFormatId::RTF );
-        else if ( aDataHelper.GetSotStorageStream( SotClipboardFormatId::RICHTEXT, xStream ) && xStream )
+        else if ( (xStream = aDataHelper.GetSotStorageStream( SotClipboardFormatId::RICHTEXT)) )
             aImpEx.ImportStream( *xStream, OUString(), SotClipboardFormatId::RICHTEXT );
         else if ( aDataHelper.GetString( SotClipboardFormatId::RICHTEXT, aStr ) )
             aImpEx.ImportString( aStr, SotClipboardFormatId::RICHTEXT );
diff --git a/sc/source/ui/view/viewfun5.cxx b/sc/source/ui/view/viewfun5.cxx
index 9f82c96df810..25e89487f96f 100644
--- a/sc/source/ui/view/viewfun5.cxx
+++ b/sc/source/ui/view/viewfun5.cxx
@@ -231,8 +231,7 @@ bool ScViewFunc::PasteDataFormat( SotClipboardFormatId nFormatId,
     }
     else if (nFormatId == SotClipboardFormatId::SVXB)
     {
-        std::unique_ptr<SvStream> xStm;
-        if( aDataHelper.GetSotStorageStream( SotClipboardFormatId::SVXB, xStm ) )
+        if (std::unique_ptr<SvStream> xStm = aDataHelper.GetSotStorageStream( SotClipboardFormatId::SVXB ) )
         {
             Graphic aGraphic;
             TypeSerializer aSerializer(*xStm);
@@ -242,8 +241,7 @@ bool ScViewFunc::PasteDataFormat( SotClipboardFormatId nFormatId,
     }
     else if ( nFormatId == SotClipboardFormatId::DRAWING )
     {
-        std::unique_ptr<SvStream> xStm;
-        if( aDataHelper.GetSotStorageStream( SotClipboardFormatId::DRAWING, xStm ) )
+        if (std::unique_ptr<SvStream> xStm = aDataHelper.GetSotStorageStream( SotClipboardFormatId::DRAWING ))
         {
             MakeDrawLayer();    // before loading model, so 3D factory has been created
 
@@ -676,8 +674,7 @@ bool ScViewFunc::PasteDataFormatFormattedText( SotClipboardFormatId nFormatId,
     pObj->SetOverwriting( true );
 
     auto pStrBuffer = std::make_shared<OUString>();
-    std::unique_ptr<SvStream> xStream;
-    if ( rDataHelper.GetSotStorageStream( nFormatId, xStream ) && xStream )
+    if (std::unique_ptr<SvStream> xStream = rDataHelper.GetSotStorageStream( nFormatId ) )
     {
         // Static variables for per-session storage. This could be
         // changed to longer-term storage in future.