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 5157899c23613ccf129f2fb59a6a99183c0b99ed..c4be647f049a306ccd52021944c0ecf3a4e5d36c 100644 (file)
--- a/src/backend/utils/adt/tid.c
+++ b/src/backend/utils/adt/tid.c
@@ -313,8 +313,13 @@ 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;
                    }
                }
            }