bug#58158: 29.0.50; [overlay] Interval tree iteration considered harmful

[Stefan Monnier]

> That's 
>
>                     [10, 12]
>                    /        \
>                  [1, 1]      [10, 11]
>                  /    \         /\
>                     [10, 13]
>                      /    \
>                           
> The 10 is found "all over the place".

"all over the place" if you consider the pre-order or post-order
traversal, indeed.  But if you look at the in-order traversal (e.g., the
one you'd get from C++ `local_Rb_tree_increment` you showed), you get
the expected result:

   [1, 1]
   [10, 13]
   [10, 12]
   [10, 11]


-- Stefan