Container:border-width caused the x/y coords converted to iters to be
offset inwards by that width, breaking positioning/selecting by gesture.
So, subtract :border-width in widget_to_text_window_coords(). This fixes
gesture positions, & plays fine with :margin & CSS margin/border/padding
N.B.: This is not to endorse :border-width. It’s gone in GTK+ 4 & weird
on a TextView: it’d be more intuitive to – if you must! – set it on the
TV parent. Really, please just use CSS instead. Still, it’s easy to fix.
https://bugzilla.gnome.org/show_bug.cgi?id=759725
gint *y)
{
GtkTextViewPrivate *priv = text_view->priv;
+ gint border_width = gtk_container_get_border_width (GTK_CONTAINER (text_view));
+
+ *x -= border_width;
+ *y -= border_width;
if (priv->top_window)
(*y) -= priv->top_window->requisition.height;