This is the commit where the "insert" signal was backported from GTK3 to GTK2:
https://git.gnome.org/browse/gtk+/commit/?h=gtk-2-24&id=5ada51d3c7d3b476d954c4fdddb4895c3de00220
This explains why the fix works. However, it still doesn't explain what happened to "child-added".
This is the commit where the "insert" signal was backported from GTK3 to GTK2:
https:/ /git.gnome. org/browse/ gtk+/commit/ ?h=gtk- 2-24&id= 5ada51d3c7d3b47 6d954c4fdddb489 5c3de00220
This explains why the fix works. However, it still doesn't explain what happened to "child-added".