v3-0001-validate-slot_name-in-parse_subscription_options.patch

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index eb88d877a5..3a033b5b8c 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -176,6 +176,8 @@ parse_subscription_options(List *stmt_options, bits32 supported_opts, SubOpts *o
 			/* Setting slot_name = NONE is treated as no slot name. */
 			if (strcmp(opts->slot_name, "none") == 0)
 				opts->slot_name = NULL;
+			else
+				ReplicationSlotValidateName(opts->slot_name, ERROR);
 		}
 		else if (IsSet(supported_opts, SUBOPT_COPY_DATA) &&
 				 strcmp(defel->defname, "copy_data") == 0)
@@ -835,6 +837,12 @@ AlterSubscription(AlterSubscriptionStmt *stmt, bool isTopLevel)
 
 				if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
 				{
+					/*
+					 * We have to disable the subscription, otherwise, the
+					 * logical replication launcher will try to start logical
+					 * replication apply worker though the new slot_name, which
+					 * doesn't exists on publisher.
+					 */
 					if (sub->enabled && !opts.slot_name)
 						ereport(ERROR,
 								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 57f7dd9b0a..4ac7259f3a 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -86,6 +86,9 @@ ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refr
 ALTER SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist2';
 ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
 -- fail
+ALTER SUBSCRIPTION regress_testsub SET (slot_name = '');
+ERROR:  replication slot name "" is too short
+-- fail
 ALTER SUBSCRIPTION regress_doesnotexist CONNECTION 'dbname=regress_doesnotexist2';
 ERROR:  subscription "regress_doesnotexist" does not exist
 ALTER SUBSCRIPTION regress_testsub SET (create_slot = false);
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 308c098c14..c9d1bd8948 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -65,6 +65,9 @@ ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refr
 ALTER SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist2';
 ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
 
+-- fail
+ALTER SUBSCRIPTION regress_testsub SET (slot_name = '');
+
 -- fail
 ALTER SUBSCRIPTION regress_doesnotexist CONNECTION 'dbname=regress_doesnotexist2';
 ALTER SUBSCRIPTION regress_testsub SET (create_slot = false);