From 7a36a4644ef72fc85ff8bec690a7e83205f2b8ad Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Wed, 12 Aug 2015 21:49:29 +0100
Subject: [PATCH] Detect face being aliased to itself

Fixes #374
---
 src/face_registry.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/face_registry.cc b/src/face_registry.cc
index cbbd32ed..5e42452d 100644
--- a/src/face_registry.cc
+++ b/src/face_registry.cc
@@ -58,6 +58,9 @@ void FaceRegistry::register_alias(const String& name, const String& facedesc,
                     [](char c){ return not isalnum(c); }))
         throw runtime_error(format("invalid alias name: '{}'", name));
 
+    if (name == facedesc)
+        throw runtime_error(format("cannot alias face '{}' to itself", name));
+
     FaceOrAlias& alias = m_aliases[name];
     auto it = m_aliases.find(facedesc);
     if (it != m_aliases.end())