gnu: automake: Adjust test to ignore new gzip warnings.

* gnu/packages/patches/automake-test-gzip-warning.patch: New file.
* gnu/packages/autotools.scm (automake)[source]: Use it.
* gnu/local.mk (dist_patch_DATA): Add it.

gnu/local.mk

@@ -435,6 +435,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/audacity-fix-ffmpeg-binding.patch	\
   %D%/packages/patches/automake-skip-amhello-tests.patch	\
   %D%/packages/patches/automake-regexp-syntax.patch		\
+  %D%/packages/patches/automake-test-gzip-warning.patch		\
   %D%/packages/patches/avahi-localstatedir.patch		\
   %D%/packages/patches/avidemux-install-to-lib.patch		\
   %D%/packages/patches/avrdude-fix-libusb.patch			\

gnu/packages/autotools.scm

@@ -218,7 +218,8 @@ output is indexed in many ways to simplify browsing.")
                "0dl6vfi2lzz8alnklwxzfz624b95hb1ipjvd3mk177flmddcf24r"))
              (patches
               (search-patches "automake-regexp-syntax.patch"
-                              "automake-skip-amhello-tests.patch"))))
+                              "automake-skip-amhello-tests.patch"
+                              "automake-test-gzip-warning.patch"))))
     (build-system gnu-build-system)
     (native-inputs
      `(("autoconf" ,(autoconf-wrapper))

gnu/packages/patches/automake-test-gzip-warning.patch

@@ -0,0 +1,17 @@
+Adjust test to ignore gzip 1.8+ warnings.
+
+--- automake-1.15/t/distcheck-no-prefix-or-srcdir-override.sh	2016-06-14 00:36:26.554218552 +0200
++++ automake-1.15/t/distcheck-no-prefix-or-srcdir-override.sh	2016-06-14 00:37:52.903157770 +0200
+@@ -49,7 +49,11 @@ grep "cannot find sources.* in foobar" s
+ 
+ ./configure
+ run_make -E -O distcheck
+-test ! -s stderr
++
++# Gzip 1.8+ emits warnings like "gzip: warning: GZIP environment
++# variable is deprecated"; filter them out.
++test `grep -v '^gzip: warning' stderr | wc -l` -eq 0
++
+ # Sanity check: the flags have been actually seen.
+ $PERL -e 'undef $/; $_ = <>; s/ \\\n/ /g; print;' <stdout >t
+ grep '/configure .* --srcdir am-src'   t || exit 99