gnu: vtk: Fix build failure.

* gnu/packages/image-processing.scm (vtk): Fix build failure.
[source]: Add patch to fix build failure with recent versions of freetype.
* gnu/packages/patches/vtk-fix-freetypetools-build-failure.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/local.mk

@@ -31,7 +31,7 @@
 # Copyright © 2020 R Veera Kumar <vkor@vkten.in>
 # Copyright © 2020 Nicolò Balzarotti <nicolo@nixo.xyz>
 # Copyright © 2020 Michael Rohleder <mike@rohleder.de>
-# Copyright © 2020 Felix Gruber <felgru@posteo.net>
+# Copyright © 2020, 2021 Felix Gruber <felgru@posteo.net>
 # Copyright © 2020 Ryan Prior <rprior@protonmail.com>
 # Copyright © 2020 Jan Wielkiewicz <tona_kosmicznego_smiecia@interia.pl>
 # Copyright © 2020 Brice Waegeneire <brice@waegenei.re>
@@ -1720,6 +1720,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/vsearch-unbundle-cityhash.patch		\
   %D%/packages/patches/vte-CVE-2012-2738-pt1.patch			\
   %D%/packages/patches/vte-CVE-2012-2738-pt2.patch			\
+  %D%/packages/patches/vtk-fix-freetypetools-build-failure.patch	\
   %D%/packages/patches/warsow-qfusion-fix-bool-return-type.patch	\
   %D%/packages/patches/webkitgtk-share-store.patch		\
   %D%/packages/patches/webkitgtk-bind-all-fonts.patch		\

gnu/packages/image-processing.scm

@@ -13,6 +13,7 @@
 ;;; Copyright © 2020 Pierre Neidhardt <mail@ambrevar.xyz>
 ;;; Copyright © 2020 Brendan Tildesley <mail@brendan.scot>
 ;;; Copyright © 2021 Oleh Malyi <astroclubzp@gmail.com>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -254,6 +255,8 @@ many popular formats.")
               (sha256
                (base32
                 "1fspgp8k0myr6p2a6wkc21ldcswb4bvmb484m12mxgk1a9vxrhrl"))
+              (patches
+               (search-patches "vtk-fix-freetypetools-build-failure.patch"))
               (modules '((guix build utils)))
               (snippet
                '(begin

gnu/packages/patches/vtk-fix-freetypetools-build-failure.patch

@@ -0,0 +1,36 @@
+This fixes a build failure in VTK when building against recent versions
+of freetype.
+
+  https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7432
+
+Patch by Ben Boeckel <ben.boeckel@kitware.com>
+
+Subject: [PATCH] vtkFreeTypeTools: avoid using an internal macro
+
+This macro has been removed upstream as it was always intended to be
+private.
+---
+ Rendering/FreeType/vtkFreeTypeTools.cxx | 7 ++-----
+ 1 file changed, 2 insertions(+), 5 deletions(-)
+
+diff --git a/Rendering/FreeType/vtkFreeTypeTools.cxx b/Rendering/FreeType/vtkFreeTypeTools.cxx
+index c54289dc60..03b899c4da 100644
+--- a/Rendering/FreeType/vtkFreeTypeTools.cxx
++++ b/Rendering/FreeType/vtkFreeTypeTools.cxx
+@@ -387,11 +387,8 @@ FTC_CMapCache* vtkFreeTypeTools::GetCMapCache()
+ }
+ 
+ //----------------------------------------------------------------------------
+-FT_CALLBACK_DEF(FT_Error)
+-vtkFreeTypeToolsFaceRequester(FTC_FaceID face_id,
+-                              FT_Library lib,
+-                              FT_Pointer request_data,
+-                              FT_Face* face)
++static FT_Error vtkFreeTypeToolsFaceRequester(
++  FTC_FaceID face_id, FT_Library lib, FT_Pointer request_data, FT_Face* face)
+ {
+ #if VTK_FTFC_DEBUG_CD
+   printf("vtkFreeTypeToolsFaceRequester()\n");
+-- 
+2.30.1
+