tdf#42982: improve UNO API error reporting

Change-Id: I9300b4e6eb9ee3ff2b9bfd32efdf0c8ceedc9d3c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/124113
Tested-by: Jenkins
Reviewed-by: Hossein <hossein@libreoffice.org>
diff --git a/embeddedobj/source/commonembedding/persistence.cxx b/embeddedobj/source/commonembedding/persistence.cxx
index 38f6f19..7d7ec8a 100644
--- a/embeddedobj/source/commonembedding/persistence.cxx
+++ b/embeddedobj/source/commonembedding/persistence.cxx
@@ -587,13 +587,13 @@ uno::Reference< io::XInputStream > OCommonEmbeddedObject::StoreDocumentToTempStr
    }

    if( !xStorable.is() )
        throw uno::RuntimeException(); // TODO:
        throw uno::RuntimeException("No storage is provided for storing!"); // TODO:

    OUString aFilterName = GetFilterName( nStorageFormat );

    SAL_WARN_IF( aFilterName.isEmpty(), "embeddedobj.common", "Wrong document service name!" );
    if ( aFilterName.isEmpty() )
        throw io::IOException(); // TODO:
        throw io::IOException("No filter name provided / Wrong document service name"); // TODO:

    uno::Sequence< beans::PropertyValue > aArgs( 4 );
    aArgs[0].Name = "FilterName";