Fix grammar in error message

While at it, make ellipses formatting consistent when describing SQL statements.

Ekaterina Kiryanova and Alexander Lakhin

Reviewed by myself and Álvaro Herrera
Discussion: https://www.postgresql.org/message-id/eed5cec0-a542-53da-6a5e-7789c6ed9817%40postgrespro.ru
Backpatch only the grammar fix to v15

src/backend/commands/subscriptioncmds.c

@@ -1187,7 +1187,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 						ereport(ERROR,
 								(errcode(ERRCODE_SYNTAX_ERROR),
 								 errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
-								 errhint("Use ALTER SUBSCRIPTION ...SET PUBLICATION with refresh = false, or with copy_data = false"
+								 errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION with refresh = false, or with copy_data = false"
 										 ", or use DROP/CREATE SUBSCRIPTION.")));
 
 					PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");
@@ -1239,7 +1239,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 						ereport(ERROR,
 								(errcode(ERRCODE_SYNTAX_ERROR),
 								 errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
-								 errhint("Use ALTER SUBSCRIPTION ...SET PUBLICATION with refresh = false, or with copy_data = false"
+								 errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION with refresh = false, or with copy_data = false"
 										 ", or use DROP/CREATE SUBSCRIPTION.")));
 
 					PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");

src/backend/postmaster/bgworker.c

@@ -663,7 +663,7 @@ SanityCheckBackgroundWorker(BackgroundWorker *worker, int elevel)
 	{
 		ereport(elevel,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("background worker \"%s\": background worker without shared memory access are not supported",
+				 errmsg("background worker \"%s\": background workers without shared memory access are not supported",
 						worker->bgw_name)));
 		return false;
 	}

src/backend/rewrite/rewriteHandler.c

@@ -578,7 +578,7 @@ rewriteRuleAction(Query *parsetree,
 		if (sub_action->hasModifyingCTE && rule_action != sub_action)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("INSERT...SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
+					 errmsg("INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
 	}
 
 	/*

src/test/regress/expected/with.out

@@ -2515,14 +2515,14 @@ SELECT * FROM bug6051_2;
  3
 (3 rows)
 
--- check INSERT...SELECT rule actions are disallowed on commands
+-- check INSERT ... SELECT rule actions are disallowed on commands
 -- that have modifyingCTEs
 CREATE OR REPLACE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD
  INSERT INTO bug6051_2
  SELECT NEW.i;
 WITH t1 AS ( DELETE FROM bug6051 RETURNING * )
 INSERT INTO bug6051 SELECT * FROM t1;
-ERROR:  INSERT...SELECT rule actions are not supported for queries having data-modifying statements in WITH
+ERROR:  INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH
 -- silly example to verify that hasModifyingCTE flag is propagated
 CREATE TEMP TABLE bug6051_3 AS
   SELECT a FROM generate_series(11,13) AS a;

src/test/regress/sql/with.sql

@@ -1169,7 +1169,7 @@ INSERT INTO bug6051 SELECT * FROM t1;
 SELECT * FROM bug6051;
 SELECT * FROM bug6051_2;
 
--- check INSERT...SELECT rule actions are disallowed on commands
+-- check INSERT ... SELECT rule actions are disallowed on commands
 -- that have modifyingCTEs
 CREATE OR REPLACE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD
  INSERT INTO bug6051_2