If it would be a double free, then that should be caught earlier, iirc. Likely to be a buffer overflow, which may be fixed meanwhile, because 3.2.3 is rather old, you should at least upgrade to latest 3.2.x.

If you got a coredump, then print the content of the fragment to see what piece of code allocated it.

Regarding the PR, the commit message is not strictly related to the code changes, but the discussion here, so it doesn't really suits for a commit history. Once I get the time to check it and all ok, then I will apply it manually, changing the commit message to be relevant for the code changes, according to:

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