(In reply to Heiko Tietze from comment #0)
> Test with https://gerrit.libreoffice.org/c/core/+/168685 or change the
> respective attribute for cui/uiconfig/ui/hyperlinkdialog.ui.

Do I understand correctly that this is something that is/can be set independently for the GtkBox of each single tab child, i.e. the tab control itself doesn't actually handle it, but it just gets a GtkWidget child?

Using `WB_SMALLICON` for the `SvtIconChoiceCtrl` seems to give a similar result to the gtk3 version, but is not configurable per tab child. Sample change to test that:

diff --git a/vcl/source/control/ivctrl.cxx b/vcl/source/control/ivctrl.cxx
index 4566ad1310b9..be5e4c774796 100644
--- a/vcl/source/control/ivctrl.cxx
+++ b/vcl/source/control/ivctrl.cxx
@@ -368,7 +368,7 @@ struct VerticalTabPageData
 
 VerticalTabControl::VerticalTabControl(vcl::Window* pParent, bool bWithIcons)
     : VclHBox(pParent)
-    , m_xChooser(VclPtr<SvtIconChoiceCtrl>::Create(this, WB_3DLOOK | (bWithIcons ?  WB_ICON : WB_DETAILS) | WB_BORDER |
+    , m_xChooser(VclPtr<SvtIconChoiceCtrl>::Create(this, WB_3DLOOK | (bWithIcons ?  WB_SMALLICON : WB_DETAILS) | WB_BORDER |
                                                          WB_NOCOLUMNHEADER |
                                                          WB_NODRAGSELECTION | WB_TABSTOP | WB_CLIPCHILDREN |
                                                          WB_NOHSCROLL))

If it were an attribute of the GtkNotebook, switching mode based on that attribute could be an option, but if it's not, I don't see a simple way to make it work in a way that's configurable independently for each single tab child.

(In reply to Michael Weghorn from comment #1)
> If it were an attribute of the GtkNotebook, switching mode based on that
> attribute could be an option, but if it's not, I don't see a simple way to
> make it work in a way that's configurable independently for each single tab
> child.

Apparently this is set via the "tab-pos" property of the "GtkNotebook", defining the position of all child tabs.

See f.i. the file paradialog.ui in Heiko's patch.

(In reply to Rafael Lima from comment #2)
> Apparently this is set via the "tab-pos" property of the "GtkNotebook",
> defining the position of all child tabs.
> 
> See f.i. the file paradialog.ui in Heiko's patch.

As far as I understand, "tab-pos" defines whether the whole tab bar is on the top or on the left, not the position of the icons within the single tab items.
(Changing it to "top" moves the tab bar to the top of the dialog, but leaves the icons left of the text in the individual tab items.)

The GtkNotebook doc [1] also mentions that `tab_label` is a GtkWidget, not just a string/char*, which allows for much more flexibility for each single item.

[1] https://docs.gtk.org/gtk3/method.Notebook.append_page.html