From 2c2b6ae45564d27b3297807cedde14bc3314401a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 14 Nov 2016 17:35:35 +0100
Subject: [PATCH] google-fonts: Add a check to ensure that there are no
 duplicate font names

Issue #20282.
---
 pkgs/data/fonts/google-fonts/default.nix | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pkgs/data/fonts/google-fonts/default.nix b/pkgs/data/fonts/google-fonts/default.nix
index ee637f880adf..fd3425e3c7c3 100644
--- a/pkgs/data/fonts/google-fonts/default.nix
+++ b/pkgs/data/fonts/google-fonts/default.nix
@@ -28,6 +28,11 @@ stdenv.mkDerivation rec {
       ofl/mrbedford \
       ofl/siamreap \
       ofl/terminaldosislight
+
+    if find . -name "*.ttf" | sed 's|.*/||' | sort | uniq -c | sort -n | grep -v '^.*1 '; then
+      echo "error: duplicate font names"
+      exit 1
+    fi
   '';
 
   installPhase = ''