See ros2/rmw_cyclonedds#228 (comment).

Why wasn't this found before?
I think it deserves some explanation, as the function has been broken for years.

The "reference implementations" (cyclone and fastrtps dynamic) of the introspection typesupport were relying on conceptually broken cpp and were also leaking.
Instead of that, they should have been using the resize and get functions provided by the introspection typesupport.
They weren't using those functions at all and those functions don't have any test, thus the error wasn't found before.

When a fix was applied in ros2/rmw_cyclonedds#228, it was found that the semantics of the "get_function" for arrays in the C introspection typesupport is different to the semantics of similar functions in the CPP introspection typesupport and also different to similar functions for bounded/unbounded sequences in the C typesupport.

See also:

• Memory leak about not to call placement delete after calling placement new rmw_cyclonedds#219
• [rmw_fastrtps_dynamic_cpp] Typesupport implementation leaks and it relies in conceptually broken cpp rmw_fastrtps#428