Attached is a sample program in Vala showing how Gee's TreeSet can leak references.  The test contains a Counter class which counts the number of instances of itself that exist.

The third test case demonstrates the bug -- a TreeSet goes out of scope without manually clearing the contents.  Even though no other references to its contents exist, the counter indicates that they were never freed!

One potential solution would be for TreeSet to add a destructor which calls clear().  Many other Gee collections do this, I think it would work here.


The first step from here is for someone to check if this still occurs in git master.