Don't malloc(0) in EventTriggerCollectAlterTSConfig

Author: Florin Irion <florin.irion@enterprisedb.com>
Discussion: https://postgr.es/m/c6fff161-9aee-4290-9ada-71e21e4d84de@gmail.com

src/backend/commands/event_trigger.c

@@ -2004,8 +2004,11 @@ EventTriggerCollectAlterTSConfig(AlterTSConfigurationStmt *stmt, Oid cfgId,
 	command->in_extension = creating_extension;
 	ObjectAddressSet(command->d.atscfg.address,
 					 TSConfigRelationId, cfgId);
-	command->d.atscfg.dictIds = palloc_array(Oid, ndicts);
-	memcpy(command->d.atscfg.dictIds, dictIds, sizeof(Oid) * ndicts);
+	if (ndicts > 0)
+	{
+		command->d.atscfg.dictIds = palloc_array(Oid, ndicts);
+		memcpy(command->d.atscfg.dictIds, dictIds, sizeof(Oid) * ndicts);
+	}
 	command->d.atscfg.ndicts = ndicts;
 	command->parsetree = (Node *) copyObject(stmt);
 

src/test/modules/test_ddl_deparse/Makefile

@@ -27,6 +27,7 @@ REGRESS = test_ddl_deparse \
 	alter_type_enum \
 	opfamily \
 	defprivs \
+	textsearch \
 	matviews
 
 EXTRA_INSTALL = contrib/pg_stat_statements

src/test/modules/test_ddl_deparse/expected/textsearch.out

@@ -0,0 +1,5 @@
+CREATE TEXT SEARCH CONFIGURATION evttrig_tscfg (COPY = pg_catalog.simple);
+NOTICE:  DDL test: type simple, tag CREATE TEXT SEARCH CONFIGURATION
+ALTER TEXT SEARCH CONFIGURATION evttrig_tscfg
+    DROP MAPPING FOR word;
+NOTICE:  DDL test: type alter text search configuration, tag ALTER TEXT SEARCH CONFIGURATION

src/test/modules/test_ddl_deparse/meson.build

@@ -47,6 +47,7 @@ tests += {
       'alter_type_enum',
       'opfamily',
       'defprivs',
+      'textsearch',
       'matviews',
     ],
   },

src/test/modules/test_ddl_deparse/sql/textsearch.sql

@@ -0,0 +1,3 @@
+CREATE TEXT SEARCH CONFIGURATION evttrig_tscfg (COPY = pg_catalog.simple);
+ALTER TEXT SEARCH CONFIGURATION evttrig_tscfg
+    DROP MAPPING FOR word;