tighten up asserting in SfxPoolItem::operator==

...subclasses, so we always call the SfxPoolItem::operatar==
which will ensure that we are always comparing two objects that
belong to the same class.

And fix the fallout in SvxUnoNameItemTable.

Change-Id: I5ec7fedaa914a328897b54c016ad13e505a15937
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/108599
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 24 insertions, 2 deletions

diff --git a/svx/source/items/chrtitem.cxx b/svx/source/items/chrtitem.cxx
index c8f502e38e3e..9ee289ea083b 100644
--- a/svx/source/items/chrtitem.cxx
+++ b/svx/source/items/chrtitem.cxx
@@ -122,6 +122,7 @@ bool SvxDoubleItem::GetPresentation
 
 bool SvxDoubleItem::operator == (const SfxPoolItem& rItem) const
 {
+    assert(SfxPoolItem::operator==(rItem));
     return static_cast<const SvxDoubleItem&>(rItem).fVal == fVal;
 }
 
diff --git a/svx/source/unodraw/UnoNameItemTable.cxx b/svx/source/unodraw/UnoNameItemTable.cxx
index 612877880ada..e8038e25a9f5 100644
--- a/svx/source/unodraw/UnoNameItemTable.cxx
+++ b/svx/source/unodraw/UnoNameItemTable.cxx
@@ -36,6 +36,27 @@
 using namespace ::com::sun::star;
 using namespace ::cppu;
 
+namespace
+{
+    // We need to override operator== here and specifically bypass the assert
+    // in SfxPoolItem::operator== in order to make the FindItemSurrogate call
+    // in SvxUnoNameItemTable::hasByName safe.
+    class SampleItem : public NameOrIndex
+    {
+    public:
+        SampleItem(sal_uInt16 nWhich, const OUString& rName) : NameOrIndex(nWhich, rName) {}
+
+        bool operator==(const SfxPoolItem& rCmp) const
+        {
+            assert(dynamic_cast<const NameOrIndex*>(&rCmp) && "comparing different pool item subclasses");
+            auto const & rOther = static_cast<const NameOrIndex&>(rCmp);
+            return GetName() == rOther.GetName() && GetPalIndex() == rOther.GetPalIndex();
+        }
+    };
+
+}
+
+
 SvxUnoNameItemTable::SvxUnoNameItemTable( SdrModel* pModel, sal_uInt16 nWhich, sal_uInt8 nMemberId ) throw()
 : mpModel( pModel ),
   mpModelPool( pModel ? &pModel->GetItemPool() : nullptr ),
@@ -187,7 +208,7 @@ uno::Any SAL_CALL SvxUnoNameItemTable::getByName( const OUString& aApiName )
 
     if (mpModelPool && !aName.isEmpty())
     {
-        NameOrIndex aSample(mnWhich, aName);
+        SampleItem aSample(mnWhich, aName);
         for (const SfxPoolItem* pFindItem : mpModelPool->FindItemSurrogate(mnWhich, aSample))
             if (isValid(static_cast<const NameOrIndex*>(pFindItem)))
             {
@@ -234,7 +255,7 @@ sal_Bool SAL_CALL SvxUnoNameItemTable::hasByName( const OUString& aApiName )
     if (!mpModelPool)
         return false;
 
-    NameOrIndex aSample(mnWhich, aName);
+    SampleItem aSample(mnWhich, aName);
     for (const SfxPoolItem* pFindItem : mpModelPool->FindItemSurrogate(mnWhich, aSample))
         if (isValid(static_cast<const NameOrIndex*>(pFindItem)))
             return true;