Comment # 6 on bug 1021476 from Bj�rn Lie

Upstream just released a new 3.20.10 gtk3, where this bugfix is one among many.

Please consider updating gtk3 wholesale.

* Bug fixes:
 358970 gtk_scale_set_digits does not cause value to be rounded if draw-value
is false...
 767391 cross-fade() not cross-fading
 770166 Can GtkButtons of arbitrary size be circular? The style class only
accommodate...
 770236 gtkbindings: Add an example for gtk_binding_entry_add_signal()
 770242 gtkbindings: Clarify that widgets need has-focus for bindings to work
 770332 Notebook arrow icon wrong color after creating new tab
 770374 Gtk Treeview Editable overshoots column width when column width is
small
 770550 gtkplacessidebar: fix signal marshal
 770614 GtkScale in HighContrast theme with value = 0: WARNING: allocates
negative con...
 770624 Fix typos.
 770703 Fix crash when using page-down on GtkListBox
 770849 GtkLabel with padding brokenness
 774695 GtkProgressbar needs full and empty classes
 774726 GtkTreeView dnd: gtk_drag_finish remove row when reorder sinse 3.20
 775525 gtk_flow_box_get_child_at_index shouldn't crash with an invalid index
 775864 getting-started: typo tie->the
 776560 icon-browser: window opens at very narrow size, only showing 1 column
of icons
 779002 Race enumerating the monitors