From ab77ea0bf25dd1f193c8dd078ef7e90523366135 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20=C4=8Cun=C3=A1t?= <v@cunat.cz>
Date: Fri, 27 Sep 2019 19:44:32 +0200
Subject: [PATCH] giflib: fix build on darwin by patch submitted upstream

It broke by the update in 3605f128.  The patch seems OK on a quick look.
---
 pkgs/development/libraries/giflib/default.nix | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/giflib/default.nix b/pkgs/development/libraries/giflib/default.nix
index d97477e3f3a..e047bdbb648 100644
--- a/pkgs/development/libraries/giflib/default.nix
+++ b/pkgs/development/libraries/giflib/default.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, xmlto, docbook_xml_dtd_412, docbook_xsl, libxml2 }:
+{ stdenv, fetchurl, fetchpatch, xmlto, docbook_xml_dtd_412, docbook_xsl, libxml2 }:
 
 stdenv.mkDerivation rec {
   name = "giflib-5.2.1";
@@ -7,6 +7,15 @@ stdenv.mkDerivation rec {
     sha256 = "1gbrg03z1b6rlrvjyc6d41bc8j1bsr7rm8206gb1apscyii5bnii";
   };
 
+  patches = stdenv.lib.optional stdenv.hostPlatform.isDarwin
+    (fetchpatch {
+      # https://sourceforge.net/p/giflib/bugs/133/
+      name = "darwin-soname.patch";
+      url = "https://sourceforge.net/p/giflib/bugs/_discuss/thread/4e811ad29b/c323/attachment/Makefile.patch";
+      sha256 = "12afkqnlkl3n1hywwgx8sqnhp3bz0c5qrwcv8j9hifw1lmfhv67r";
+      extraPrefix = "./";
+    });
+
   postPatch = ''
     substituteInPlace Makefile \
       --replace 'PREFIX = /usr/local' 'PREFIX = ${builtins.placeholder "out"}'