MDEV-18184 Do not copy temporary files (prefixed with #sql-) to backup

extra/mariabackup/xtrabackup.cc

@@ -2392,6 +2392,18 @@ check_if_skip_table(
 	const char *ptr;
 	char *eptr;
 
+
+	dbname = NULL;
+	tbname = name;
+	while ((ptr = strchr(tbname, '/')) != NULL) {
+		dbname = tbname;
+		tbname = ptr + 1;
+	}
+
+	if (strncmp(tbname, "#sql",4) == 0) {
+		return TRUE;
+	}
+
 	if (regex_exclude_list.empty() &&
 		regex_include_list.empty() &&
 		tables_include_hash == NULL &&
@@ -2401,13 +2413,6 @@ check_if_skip_table(
 		return(FALSE);
 	}
 
-	dbname = NULL;
-	tbname = name;
-	while ((ptr = strchr(tbname, '/')) != NULL) {
-		dbname = tbname;
-		tbname = ptr + 1;
-	}
-
 	if (dbname == NULL) {
 		return(FALSE);
 	}