Fix use-after-release mistake in currtid() and currtid2() for views

This issue has been present since the introduction of this code as of
a3519a2 from 2002, and has been found by buildfarm member prion that
uses RELCACHE_FORCE_RELEASE via the tests introduced recently in
e786be5.

Discussion: https://postgr.es/m/20200601022055[email protected]
Backpatch-through: 9.5

diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
index 8453b65e78aaed5002e261ed1f66e5adf046d53e..75d04280ee94f2c8f1e6377ec6e136409424a75d 100644 (file)
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -309,8 +309,13 @@ currtid_for_view(Relation viewrel, ItemPointer tid)
                    rte = rt_fetch(var->varno, query->rtable);
                    if (rte)
                    {
+                       Datum       result;
+
+                       result = DirectFunctionCall2(currtid_byreloid,
+                                                    ObjectIdGetDatum(rte->relid),
+                                                    PointerGetDatum(tid));
                        heap_close(viewrel, AccessShareLock);
-                       return DirectFunctionCall2(currtid_byreloid, ObjectIdGetDatum(rte->relid), PointerGetDatum(tid));
+                       return result;
                    }
                }
            }