Related: fdo#71764 allow extensions button to group with help

even though they are in different containers

Change-Id: I785166c577acab03608da10fb4a33072458a82cd
diff --git a/sfx2/source/dialog/backingwindow.cxx b/sfx2/source/dialog/backingwindow.cxx
index fcfdfc2..8744b07 100644
--- a/sfx2/source/dialog/backingwindow.cxx
+++ b/sfx2/source/dialog/backingwindow.cxx
@@ -87,6 +87,26 @@ BackingWindow::BackingWindow( Window* i_pParent ) :
    get(mpHelpButton, "help");
    get(mpExtensionsButton, "extensions");

    //Containers are invisible to cursor traversal
    //So on pressing "right" when in Help the
    //extension button is considered as a candidate
    //
    //But the containers are not invisible to the PushButton ctor which checks
    //if the preceeding window of its parent is a button and if it then
    //defaults to grouping with it and if it is not a button defaults to
    //setting itself as the start of a new group.
    //
    //So here take the second button and set it as explicitly not the start
    //of a group, i.e. allow it to be grouped with the preceeding
    //PushButton so when seen as a candidate by cursor travelling
    //it will be accepted as a continuation of the group.
    WinBits nBits = mpExtensionsButton->GetStyle();
    nBits &= ~WB_GROUP;
    nBits |= WB_NOGROUP;
    mpExtensionsButton->SetStyle(nBits);
    assert(mpHelpButton->GetStyle() & WB_GROUP);
    assert(!(mpExtensionsButton->GetStyle() & WB_GROUP));

    get(mpAllButtonsBox, "all_buttons_box");
    get(mpButtonsBox, "buttons_box");
    get(mpSmallButtonsBox, "small_buttons_box");