Data of pivot table with external source is imported as string items.
When grouping is done in `ScDPSaveGroupDimension::AddToCache`,
`ScDPSaveGroupItem::ConvertElementsToItems` converts string numbers to
double items, but the source contains string item for the same data.
Because of this mismatch grouping is not preserved.
bug-document: forum-mso-en4-58929.xls
Change-Id: If32311204eca4009ec2a00e37271f7bd5cc2d45c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/202734
Reviewed-by: Balazs Varga <balazs.varga@collabora.com>
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Signed-off-by: Xisco Fauli <xiscofauli@libreoffice.org>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/204229
Tested-by: Jenkins
Karthik Godha
30d4e1add8