R: import upstream patch to fix broken "R CMD Sweave" command

The command "R CMD Sweave" always exits with error code "1", even if the
command was successful. This upstream patch remedies this issue.

pkgs/applications/science/math/R/default.nix

@@ -1,7 +1,7 @@
 { stdenv, fetchurl, bzip2, gfortran, libX11, libXmu, libXt, libjpeg, libpng
 , libtiff, ncurses, pango, pcre, perl, readline, tcl, texLive, tk, xz, zlib
 , less, texinfo, graphviz, icu, pkgconfig, bison, imake, which, jdk, openblas
-, curl, Cocoa, Foundation, cf-private, libobjc, tzdata
+, curl, Cocoa, Foundation, cf-private, libobjc, tzdata, fetchpatch
 , withRecommendedPackages ? true
 , enableStrictBarrier ? false
 }:
@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
   ] ++ stdenv.lib.optionals (!stdenv.isDarwin) [ tcl tk ]
     ++ stdenv.lib.optionals stdenv.isDarwin [ Cocoa Foundation cf-private libobjc ];
 
-  patches = [ ./no-usr-local-search-paths.patch ];
+  patches = [ ./no-usr-local-search-paths.patch ./fix-sweave-exit-code.patch ];
 
   preConfigure = ''
     configureFlagsArray=(

pkgs/applications/science/math/R/fix-sweave-exit-code.patch

@@ -0,0 +1,52 @@
+From 0ff560ba912fad126576818519035c8d3c693bed Mon Sep 17 00:00:00 2001
+From: maechler <maechler@00db46b3-68df-0310-9c12-caf00c1e9a41>
+Date: Mon, 24 Apr 2017 14:24:11 +0000
+Subject: [PATCH] R CMD Sweave status bug fix
+
+git-svn-id: https://svn.r-project.org/R/trunk@72612 00db46b3-68df-0310-9c12-caf00c1e9a41
+
+diff --git a/src/library/utils/R/Sweave.R b/src/library/utils/R/Sweave.R
+index 2beb094..8d4950b 100644
+--- a/src/library/utils/R/Sweave.R
++++ b/src/library/utils/R/Sweave.R
+@@ -1,7 +1,7 @@
+ #   File src/library/utils/R/Sweave.R
+ #  Part of the R package, https://www.R-project.org
+ #
+-#  Copyright (C) 1995-2016 The R Core Team
++#  Copyright (C) 1995-2017 The R Core Team
+ #
+ #  This program is free software; you can redistribute it and/or modify
+ #  it under the terms of the GNU General Public License as published by
+@@ -452,10 +452,10 @@ SweaveHooks <- function(options, run = FALSE, envir = .GlobalEnv)
+     }
+     do_exit <-
+ 	if(no.q)
+-	    function(status = 1L) (if(status) stop else message)(
++	    function(status = 0L) (if(status) stop else message)(
+ 		".Sweave() exit status ", status)
+ 	else
+-	    function(status = 1L) q("no", status = status, runLast = FALSE)
++	    function(status = 0L) q("no", status = status, runLast = FALSE)
+
+     if (!length(args)) {
+         Usage()
+@@ -577,16 +577,15 @@ SweaveHooks <- function(options, run = FALSE, envir = .GlobalEnv)
+     }
+     do_exit <-
+ 	if(no.q)
+-	    function(status = 1L) (if(status) stop else message)(
++	    function(status = 0L) (if(status) stop else message)(
+ 		".Stangle() exit status ", status)
+ 	else
+-	    function(status = 1L) q("no", status = status, runLast = FALSE)
++	    function(status = 0L) q("no", status = status, runLast = FALSE)
+
+     if (!length(args)) {
+         Usage()
+         do_exit(1L)
+     }
+-
+     file <- character()
+     encoding <- options <- ""
+     engine <- NULL