182db07040
Commit 08dd23cec introduced an exception to the rule that extension member objects can only be dropped as part of dropping the whole extension, intending to allow such drops while running the extension's own creation or update scripts. However, the exception was only applied at the outermost recursion level, because it was modeled on a pre-existing check to ignore dependencies on objects listed in pendingObjects. Bug #14434 from Philippe Beaudoin shows that this is inadequate: in some cases we can reach an extension member object by recursion from another one. (The bug concerns the serial-sequence case; I'm not sure if there are other cases, but there might well be.) To fix, revert 08dd23cec's changes to findDependentObjects() and instead apply the creating_extension exception regardless of stack level. Having seen this example, I'm a bit suspicious that the pendingObjects logic is also wrong and such cases should likewise be allowed at any recursion level. However, changing that would interact in subtle ways with the recursion logic (at least it would need to be moved to after the recursing-from check). Given that the code's been like that a long time, I'll refrain from touching it without a clear example showing it's wrong. Back-patch to all active branches. In HEAD and 9.6, where suitable test infrastructure exists, add a regression test case based on the bug report. Report: <20161125151448.6529.33039@wrigleys.postgresql.org> Discussion: <13224.1480177514@sss.pgh.pa.us>
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