Undo adding set_redo_start_lsn function to walproposer API

pgxn/neon/walproposer.c

@@ -1379,12 +1379,7 @@ ProcessPropStartPos(WalProposer *wp)
 	 * we must bail out, as clog and other non rel data is inconsistent.
 	 */
 	walprop_shared = wp->api.get_shmem_state(wp);
-	if (wp->api.get_shmem_state(wp)->bgw_started)
-	{
-		/* Replica promotion */
-		wp->api.set_redo_start_lsn(wp, wp->propTermStartLsn);
-	}
-	else if (!wp->config->syncSafekeepers)
+	if (!wp->config->syncSafekeepers && !wp->api.get_shmem_state(wp)->bgw_started)
 	{
 		/*
 		 * Basebackup LSN always points to the beginning of the record (not

pgxn/neon/walproposer.h

@@ -675,12 +675,6 @@ typedef struct walproposer_api
 	 */
 	XLogRecPtr	(*get_redo_start_lsn) (WalProposer *wp);
 
-	/*
-	 * Get a basebackup LSN. Used to cross-validate with the latest available
-	 * LSN on the safekeepers.
-	 */
-	void 		(*set_redo_start_lsn) (WalProposer *wp, XLogRecPtr lsn);
-
 	/*
 	 * Finish sync safekeepers with the given LSN. This function should not
 	 * return and should exit the program.

pgxn/neon/walproposer_pg.c

@@ -2040,13 +2040,6 @@ walprop_pg_get_redo_start_lsn(WalProposer *wp)
 	return GetRedoStartLsn();
 }
 
-static void
-walprop_pg_set_redo_start_lsn(WalProposer *wp, XLogRecPtr lsn)
-{
-#if PG_VERSION_NUM >= 150000
-	SetRedoStartLsn(lsn);
-#endif
-}
 
 static bool
 walprop_pg_strong_random(WalProposer *wp, void *buf, size_t len)
@@ -2103,7 +2096,6 @@ static const walproposer_api walprop_pg = {
 	.wait_event_set = walprop_pg_wait_event_set,
 	.strong_random = walprop_pg_strong_random,
 	.get_redo_start_lsn = walprop_pg_get_redo_start_lsn,
-	.set_redo_start_lsn = walprop_pg_set_redo_start_lsn,
 	.finish_sync_safekeepers = walprop_pg_finish_sync_safekeepers,
 	.process_safekeeper_feedback = walprop_pg_process_safekeeper_feedback,
 	.log_internal = walprop_pg_log_internal,

test_runner/regress/test_replica_promote.py

@@ -5,12 +5,14 @@ This far, only contains a test that we don't break and that the data is persiste
 """
 
 import psycopg2
+import pytest
 import time
 from fixtures.neon_fixtures import Endpoint, NeonEnv, wait_replica_caughtup
 from fixtures.pg_version import PgVersion
+from fixtures.log_helper import log
 from pytest import raises
 
-
+@pytest.mark.timeout(6000)
 def test_replica_promotes(neon_simple_env: NeonEnv, pg_version: PgVersion):
     """
     Test that a replica safely promotes, and can commit data updates which
@@ -79,18 +81,32 @@ def test_replica_promotes(neon_simple_env: NeonEnv, pg_version: PgVersion):
     secondary_cur.execute(f"alter system set neon.safekeepers='{safekeepers}'")
     secondary_cur.execute("select pg_reload_conf()");
 
-    new_primary_conn = secondary.connect()
+    new_primary = secondary
+    old_primary = primary
+
+    new_primary_conn = new_primary.connect()
     new_primary_cur = new_primary_conn.cursor()
     new_primary_cur.execute("INSERT INTO t (payload) SELECT generate_series(101, 200)")
 
     new_primary_cur.execute("select count(*) from t")
     assert new_primary_cur.fetchone() == (200,)
+    new_primary_cur.execute("select pg_current_wal_flush_lsn()")
+    lsn = new_primary_cur.fetchall()[0][0]
+    log.info(f"New primary flush LSN={lsn}")
 
-    secondary.stop(mode="immediate")
+    new_primary.stop(mode="immediate")
+    new_primary.hot_standby = False
+    new_primary.start()
 
-    primary.start()
+    with new_primary.connect() as new_primary_conn:
+        new_primary_cur = new_primary_conn.cursor()
+        new_primary_cur.execute("select count(*) from t")
+        assert new_primary_cur.fetchone() == (200,)
 
-    with primary.connect() as primary_conn:
-        primary_cur = primary_conn.cursor()
-        primary_cur.execute("select count(*) from t")
-        assert primary_cur.fetchone() == (200,)
+    new_primary.stop()
+    old_primary.start()
+
+    with old_primary.connect() as old_primary_conn:
+        old_primary_cur = old_primary_conn.cursor()
+        old_primary_cur.execute("select count(*) from t")
+        assert old_primary_cur.fetchone() == (200,)