Feature CORE-2777 - Make possible to alter the default database chara…

…cter set without manual update of system table

src/dsql/ddl.cpp

@@ -4254,6 +4254,10 @@ static void modify_database( CompiledStatement* statement)
 		case nod_end_backup:
 			statement->append_uchar(isc_dyn_end_backup);
 			break;
+		case nod_dfl_charset:
+			statement->append_cstring(isc_dyn_fld_character_set_name,
+				((dsql_str*) element->nod_arg[0])->str_data);
+			break;
 		default:
 			break;
 		}

src/dsql/parse.y

@@ -3158,17 +3158,20 @@ alter_db	: db_alter_clause
 				{ $$ = make_node (nod_list, (int) 2, $1, $2); }
 		;
 
-db_alter_clause : ADD db_file_list
-			{ $$ = $2; }
-		| ADD KW_DIFFERENCE KW_FILE sql_string
-			{ $$ = make_node (nod_difference_file, (int) 1, $4); }
-		| DROP KW_DIFFERENCE KW_FILE
-			{ $$ = make_node (nod_drop_difference, (int) 0, NULL); }
-		| BEGIN BACKUP
-			{ $$ = make_node (nod_begin_backup, (int) 0, NULL); }
-		| END BACKUP
-			{ $$ = make_node (nod_end_backup, (int) 0, NULL); }
-		;
+db_alter_clause
+	: ADD db_file_list
+		{ $$ = $2; }
+	| ADD KW_DIFFERENCE KW_FILE sql_string
+		{ $$ = make_node(nod_difference_file, (int) 1, $4); }
+	| DROP KW_DIFFERENCE KW_FILE
+		{ $$ = make_node(nod_drop_difference, (int) 0, NULL); }
+	| BEGIN BACKUP
+		{ $$ = make_node(nod_begin_backup, (int) 0, NULL); }
+	| END BACKUP
+		{ $$ = make_node(nod_end_backup, (int) 0, NULL); }
+	| SET DEFAULT CHARACTER SET symbol_character_set_name
+		{ $$ = make_node(nod_dfl_charset, 1, $5); }
+	;
 
 
 // ALTER TRIGGER

src/jrd/dyn_mod.epp

@@ -305,6 +305,9 @@ void DYN_modify_database( Global* gbl, const UCHAR** ptr)
 						break;
 
 					case isc_dyn_fld_character_set_name:
+						if (!tdbb->getAttachment()->locksmith())
+							ERR_post(Arg::Gds(isc_adm_task_denied));
+
 						if (GET_STRING(ptr, DBB.RDB$CHARACTER_SET_NAME))
 							DBB.RDB$CHARACTER_SET_NAME.NULL = FALSE;
 						else