There is a bug report[0] Tender comments might be the same issue as this one, but I tried Alvaro's and mine patch, neither could solve that problem, I did not tried Tender's earlier patch thought. I post the test script below in case you are interested.
My earlier patch should handle Alexander reported case. But I did not do more
test. I'm not sure that wether or not has dismatching between pg_constraint and pg_trigger.
I aggred with Alvaro said that "requires a much more invasive solution".
