Scrolling via gtk_container_set_focus_{h,v}adjustment() ignores margin, CSS spacing
GtkWidget margins and CSS box spacing (margin, border, padding) is not taken into account when a GtkContainer has been set up to automatically scroll as the focus changes via gtk_container_set_focus_{h,v}adjustment().
Currently, if any descendants of the container have margins or CSS spacing set, that is ignored when calculating the distance needed to scroll to make a currently hidden control visible. So when the user tabs/etc to it, it will be only partially revealed, or not revealed at all, depending on the amount of space added and how far off the edge the widget is. For example, with a UI like the control center's scrollable GtkListBoxes where these are used for controlling spacing, then the amount scrolled can easily be off by a large amount.
GtkContainer uses the child's allocation and gtk_widget_translate_coordinates() (which also only uses widget allocations) to determine the distance needed to scroll, which like #1138 (closed) seems to be the cause?
This doesn't look like it will be a problem for GTK+ master, which looking at the code does seem to take CSS props into account, only for GTK+ 3.x.