provide-portal-snapshot-for-simple-exprs-too.patch

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 0ce382e123..96bb77e0b1 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -38,6 +38,7 @@
 #include "plpgsql.h"
 #include "storage/proc.h"
 #include "tcop/cmdtag.h"
+#include "tcop/pquery.h"
 #include "tcop/tcopprot.h"
 #include "tcop/utility.h"
 #include "utils/array.h"
@@ -5958,6 +5959,15 @@ exec_eval_simple_expr(PLpgSQL_execstate *estate,
 		expr->expr_simple_lxid == curlxid)
 		return false;
 
+	/*
+	 * Ensure that there's a portal-level snapshot, in case this simple
+	 * expression is the first thing evaluated after a COMMIT or ROLLBACK.
+	 * We'd have to do this anyway before executing the expression, so we
+	 * might as well do it now to ensure that any possible replanning doesn't
+	 * need to take a new snapshot.
+	 */
+	EnsurePortalSnapshotExists();
+
 	/*
 	 * Check to see if the cached plan has been invalidated.  If not, and this
 	 * is the first use in the current transaction, save a plan refcount in