unordered_set move leads to crash in 1.80.0

[ergpudb]

This code segfaults in 1.80.0 but not 1.79.0 (nor using std::unordered_set):

    boost::unordered_set<std::string> a;
    boost::unordered_set<std::string> b = std::move(a);
    boost::unordered_set<std::string> c = std::move(a);
    c.clear(); // <-- segfault

Based on the standard, the first move should leave a in a "valid but unspecified state"; since a should still be valid, moving from it a second time presumably should not corrupt c (even if the contents of c are technically unspecified afterward).

Note: it appears that unordered_map also exhibits the same behavior.

[ergpudb]

Even simpler (no double move):

    boost::unordered_set<std::string> a;
    boost::unordered_set<std::string> b = std::move(a);
    a.clear(); // <-- segfault

[cmazakas]

Thank you for the bug report!

I've replicated this issue locally and am aware of the cause.

I'm working on the fix.

[cmazakas]

@ergpudb this fix will be landing in 1.81. In the interim, I'm going to close the issue.