Tom, I can still trigger the old bug for which we thought we'd pushed a fix. The test case below crashes on master (e12694523e7e4482a052236f12d3d8b58be9a22c), and also on the fixed version "Make regexp engine's backref-related compilation state more bulletproof." (cb76fbd7ec87e44b3c53165d68dc2747f7e26a9a).
Can you test if it crashes for you, too? I'm not sure I see why this one fails when millions of others pass. The backtrace is still complaining about regc_nfa.c:1265: +select regexp_split_to_array('', '(?:((?:q+))){0}(\1){0,0}?*[^]'); +server closed the connection unexpectedly + This probably means the server terminated abnormally + before or while processing the request. +connection to server was lost — Mark Dilger EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company