tdf#93018 - Copying forms not working anymore (part2)

I missed a similar bug lower down

Change-Id: I673c69dd1d36cc1b502a7de7821a05d859313aac
(cherry picked from commit 0c08cb23)
Reviewed-on: https://gerrit.libreoffice.org/17537Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>

sot/source/base/exchange.cxx

@@ -286,16 +286,14 @@ SotClipboardFormatId SotExchange::RegisterFormatMimeType( const OUString& rMimeT
             return static_cast<SotClipboardFormatId>(i + static_cast<int>(SotClipboardFormatId::USER_END) + 1);
     }
 
-    // nMax ist der neue Platz
     DataFlavor* pNewFlavor = new DataFlavor;
-
     pNewFlavor->MimeType = rMimeType;
     pNewFlavor->HumanPresentableName = rMimeType;
     pNewFlavor->DataType = cppu::UnoType<OUString>::get();
 
     rL.push_back( pNewFlavor );
 
-    return static_cast<SotClipboardFormatId>(static_cast<int>(nMax) + static_cast<int>(SotClipboardFormatId::USER_END) + 1);
+    return static_cast<SotClipboardFormatId>(static_cast<int>(rL.size()-1) + static_cast<int>(SotClipboardFormatId::USER_END) + 1);
 }
 
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