diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 6e262d1a3a..22d0fe5ac4 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -241,6 +241,14 @@ _SPI_commit(bool chain)
 				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
 				 errmsg("cannot commit while a subtransaction is active")));
 
+	/*
+	 * Hold any pinned portals that any PLs might be using.  We have to do
+	 * this before changing transaction state, since this will run
+	 * user-defined code that might throw an error.
+	 */
+	HoldPinnedPortals();
+
+	/* Start the actual commit */
 	_SPI_current->internal_xact = true;
 
 	/*
@@ -294,6 +302,15 @@ _SPI_rollback(bool chain)
 				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
 				 errmsg("cannot roll back while a subtransaction is active")));
 
+	/*
+	 * Hold any pinned portals that any PLs might be using.  We have to do
+	 * this before changing transaction state, since this will run
+	 * user-defined code that might throw an error, and in any case couldn't
+	 * be run in an already-aborted transaction.
+	 */
+	HoldPinnedPortals();
+
+	/* Start the actual rollback */
 	_SPI_current->internal_xact = true;
 
 	if (chain)
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index a92b4541bd..334e35bb6a 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1226,13 +1226,19 @@ ThereAreNoReadyPortals(void)
 /*
  * Hold all pinned portals.
  *
- * A procedural language implementation that uses pinned portals for its
- * internally generated cursors can call this in its COMMIT command to convert
- * those cursors to held cursors, so that they survive the transaction end.
- * We mark those portals as "auto-held" so that exception exit knows to clean
- * them up.  (In normal, non-exception code paths, the PL needs to clean those
- * portals itself, since transaction end won't do it anymore, but that should
- * be normal practice anyway.)
+ * When initiating a COMMIT or ROLLBACK inside a procedure, this must be
+ * called to protect internally-generated cursors from being dropped during
+ * the transaction shutdown.  Currently, SPI calls this automatically; PLs
+ * that initiate COMMIT or ROLLBACK some other way are on the hook to do it
+ * themselves.  (Note that we couldn't do this in, say, AtAbort_Portals
+ * because we need to run user-defined code while persisting a portal.
+ * It's too late to do that once transaction abort has started.)
+ *
+ * We protect such portals by converting them to held cursors.  We mark them
+ * as "auto-held" so that exception exit knows to clean them up.  (In normal,
+ * non-exception code paths, the PL needs to clean such portals itself, since
+ * transaction end won't do it anymore; but that should be normal practice
+ * anyway.)
  */
 void
 HoldPinnedPortals(void)
@@ -1262,8 +1268,12 @@ HoldPinnedPortals(void)
 						(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
 						 errmsg("cannot perform transaction commands inside a cursor loop that is not read-only")));
 
-			portal->autoHeld = true;
+			/* Verify it's in a suitable state to be held */
+			if (portal->status != PORTAL_READY)
+				elog(ERROR, "pinned portal is not ready to be auto-held");
+
 			HoldPortal(portal);
+			portal->autoHeld = true;
 		}
 	}
 }
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 31ba2f262f..bda9517971 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -3988,8 +3988,6 @@ plperl_spi_commit(void)
 
 	PG_TRY();
 	{
-		HoldPinnedPortals();
-
 		SPI_commit();
 		SPI_start_transaction();
 	}
@@ -4015,8 +4013,6 @@ plperl_spi_rollback(void)
 
 	PG_TRY();
 	{
-		HoldPinnedPortals();
-
 		SPI_rollback();
 		SPI_start_transaction();
 	}
diff --git a/src/pl/plpgsql/src/expected/plpgsql_transaction.out b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
index ba0745326a..5f576231c3 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_transaction.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
@@ -401,6 +401,50 @@ SELECT * FROM test3;
  1
 (1 row)
 
+-- failure while trying to persist a cursor across a transaction (bug #15703)
+CREATE PROCEDURE cursor_fail_during_commit()
+ LANGUAGE plpgsql
+AS $$
+  DECLARE id int;
+  BEGIN
+    FOR id IN SELECT 1/(x-1000) FROM generate_series(1,1000) x LOOP
+        INSERT INTO test1 VALUES(id);
+        COMMIT;
+    END LOOP;
+  END;
+$$;
+TRUNCATE test1;
+CALL cursor_fail_during_commit();
+ERROR:  division by zero
+CONTEXT:  PL/pgSQL function cursor_fail_during_commit() line 6 at COMMIT
+-- note that error occurs during first COMMIT, hence nothing is in test1
+SELECT count(*) FROM test1;
+ count 
+-------
+     0
+(1 row)
+
+CREATE PROCEDURE cursor_fail_during_rollback()
+ LANGUAGE plpgsql
+AS $$
+  DECLARE id int;
+  BEGIN
+    FOR id IN SELECT 1/(x-1000) FROM generate_series(1,1000) x LOOP
+        INSERT INTO test1 VALUES(id);
+        ROLLBACK;
+    END LOOP;
+  END;
+$$;
+TRUNCATE test1;
+CALL cursor_fail_during_rollback();
+ERROR:  division by zero
+CONTEXT:  PL/pgSQL function cursor_fail_during_rollback() line 6 at ROLLBACK
+SELECT count(*) FROM test1;
+ count 
+-------
+     0
+(1 row)
+
 -- SET TRANSACTION
 DO LANGUAGE plpgsql $$
 BEGIN
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index f0005009b2..23aed02dbd 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -4791,8 +4791,6 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 static int
 exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
 {
-	HoldPinnedPortals();
-
 	if (stmt->chain)
 		SPI_commit_and_chain();
 	else
@@ -4815,8 +4813,6 @@ exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
 static int
 exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
 {
-	HoldPinnedPortals();
-
 	if (stmt->chain)
 		SPI_rollback_and_chain();
 	else
diff --git a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
index 0c137dd31d..7575655c1a 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
@@ -329,6 +329,44 @@ $$;
 
 SELECT * FROM test3;
 
+-- failure while trying to persist a cursor across a transaction (bug #15703)
+CREATE PROCEDURE cursor_fail_during_commit()
+ LANGUAGE plpgsql
+AS $$
+  DECLARE id int;
+  BEGIN
+    FOR id IN SELECT 1/(x-1000) FROM generate_series(1,1000) x LOOP
+        INSERT INTO test1 VALUES(id);
+        COMMIT;
+    END LOOP;
+  END;
+$$;
+
+TRUNCATE test1;
+
+CALL cursor_fail_during_commit();
+
+-- note that error occurs during first COMMIT, hence nothing is in test1
+SELECT count(*) FROM test1;
+
+CREATE PROCEDURE cursor_fail_during_rollback()
+ LANGUAGE plpgsql
+AS $$
+  DECLARE id int;
+  BEGIN
+    FOR id IN SELECT 1/(x-1000) FROM generate_series(1,1000) x LOOP
+        INSERT INTO test1 VALUES(id);
+        ROLLBACK;
+    END LOOP;
+  END;
+$$;
+
+TRUNCATE test1;
+
+CALL cursor_fail_during_rollback();
+
+SELECT count(*) FROM test1;
+
 
 -- SET TRANSACTION
 DO LANGUAGE plpgsql $$
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23e49e4b75..f40f0846bb 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -588,8 +588,6 @@ PLy_commit(PyObject *self, PyObject *args)
 {
 	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
 
-	HoldPinnedPortals();
-
 	SPI_commit();
 	SPI_start_transaction();
 
@@ -604,8 +602,6 @@ PLy_rollback(PyObject *self, PyObject *args)
 {
 	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
 
-	HoldPinnedPortals();
-
 	SPI_rollback();
 	SPI_start_transaction();