pgsql: Don't allocate memory for default arguments (#20757)

Author: ndossche

ext/pgsql/pgsql.c

@@ -3350,9 +3350,8 @@ PHP_FUNCTION(pg_copy_to)
 	pgsql_link_handle *link;
 	zend_string *table_name;
 	zend_string *pg_delimiter = NULL;
-	char *pg_null_as = NULL;
+	char *pg_null_as = "\\\\N";
 	size_t pg_null_as_len = 0;
-	bool free_pg_null = false;
 	char *query;
 	PGconn *pgsql;
 	PGresult *pgsql_result;
@@ -3377,20 +3376,13 @@ PHP_FUNCTION(pg_copy_to)
 		zend_argument_value_error(3, "must be one character");
 		RETURN_THROWS();
 	}
-	if (!pg_null_as) {
-		pg_null_as = estrdup("\\\\N");
-		free_pg_null = true;
-	}
 
 	spprintf(&query, 0, "COPY %s TO STDOUT DELIMITER E'%c' NULL AS E'%s'", ZSTR_VAL(table_name), *ZSTR_VAL(pg_delimiter), pg_null_as);
 
 	while ((pgsql_result = PQgetResult(pgsql))) {
 		PQclear(pgsql_result);
 	}
 	pgsql_result = PQexec(pgsql, query);
-	if (free_pg_null) {
-		efree(pg_null_as);
-	}
 	efree(query);
 
 	if (pgsql_result) {
@@ -3475,9 +3467,8 @@ PHP_FUNCTION(pg_copy_from)
 	zval *value;
 	zend_string *table_name;
 	zend_string *pg_delimiter = NULL;
-	char *pg_null_as = NULL;
+	char *pg_null_as = "\\\\N";
 	size_t pg_null_as_len;
-	bool pg_null_as_free = false;
 	char *query;
 	PGconn *pgsql;
 	PGresult *pgsql_result;
@@ -3502,20 +3493,13 @@ PHP_FUNCTION(pg_copy_from)
 		zend_argument_value_error(4, "must be one character");
 		RETURN_THROWS();
 	}
-	if (!pg_null_as) {
-		pg_null_as = estrdup("\\\\N");
-		pg_null_as_free = true;
-	}
 
 	spprintf(&query, 0, "COPY %s FROM STDIN DELIMITER E'%c' NULL AS E'%s'", ZSTR_VAL(table_name), *ZSTR_VAL(pg_delimiter), pg_null_as);
 	while ((pgsql_result = PQgetResult(pgsql))) {
 		PQclear(pgsql_result);
 	}
 	pgsql_result = PQexec(pgsql, query);
 
-	if (pg_null_as_free) {
-		efree(pg_null_as);
-	}
 	efree(query);
 
 	if (pgsql_result) {