Guard iAttachment.detach() against an already-released interface (1.x backport of #69) - #78
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aminghadersohi wants to merge 1 commit into
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Backport of the FirebirdSQL#69 fix (FirebirdSQL#72) to release-1.x. During cyclic garbage collection the iAttachment's own iReferenceCounted.__del__ may run release() before Connection.__del__ calls detach(); the v5 detach() override then dereferenced freed memory and segfaulted. Restore the if self._refcnt guard that iAttachment_v4.detach() already has. Fixes FirebirdSQL#77.
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Backport of the #69 fix (#72, merged to
masteron 2026-05-21) torelease-1.x. Fixes #77.On 1.x, the v5
iAttachment.detach()override calls the nativedetachwithout theif self._refcnt:guard thatiAttachment_v4.detach()has. When the garbage collector finalizes a connection that was never closed, the interface can already be released, andConnection.__del__then detaches freed memory, which segfaults the process.The change restores the guard, the same code as on
master.Verification against Firebird 5.0.3, CPython 3.11.15, Linux x86_64, with firebird-base 1.8.0, using the reproduction script in #77 (100 abandoned connections, each followed by
gc.collect()):release-1.x(1.10.11): segfault ininterfaces.pydetachin 3 of 3 runs (exit 139)The master regression test (
tests/test_issues.py::test_issue_69_gc_of_abandoned_connection) relies on the pytest layout, whichrelease-1.xdoes not have, so it is not ported here. The standalone script in #77 reproduces the crash on this branch.