From a6cd26740baae696115a7b501b6bf449321acebd Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Sat, 2 Dec 2017 04:10:47 +0100
Subject: [PATCH] gtk_doc: propagate the respect-xml-catalog-files-var.patch

We are patching the xmlcatalog calls in the JH_CHECK_XML_CATALOG
macro to use the XML_CATALOG_FILES environment variable instead
of a single central catalog file. Since consumers (libraries or
applications) are expected to copy the m4 files to their source
tree, we need to patch them separately. The files should be
identical, though, so we can reuse the patch for gtk_doc.

This commit makes the patch available in passthru so the consumer
expressions do not need to maintain the long relative path.
---
 pkgs/development/tools/documentation/gtk-doc/default.nix | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/tools/documentation/gtk-doc/default.nix b/pkgs/development/tools/documentation/gtk-doc/default.nix
index 5f31a2dfb7c6..b88b8e3c82a9 100644
--- a/pkgs/development/tools/documentation/gtk-doc/default.nix
+++ b/pkgs/development/tools/documentation/gtk-doc/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   };
 
   patches = [
-    ./respect-xml-catalog-files-var.patch
+    passthru.respect_xml_catalog_files_var_patch
   ];
 
   outputDevdoc = "out";
@@ -24,6 +24,11 @@ stdenv.mkDerivation rec {
 
   configureFlags = "--disable-scrollkeeper";
 
+  passthru = {
+    # Consumers are expected to copy the m4 files to their source tree, let them reuse the patch
+    respect_xml_catalog_files_var_patch = ./respect-xml-catalog-files-var.patch;
+  };
+
   meta = with stdenv.lib; {
     homepage = https://www.gtk.org/gtk-doc;
     description = "Tools to extract documentation embedded in GTK+ and GNOME source code";