distro: tar: Allow builds with glibc 2.16+.

* distro/patches/tar-gets-undeclared.patch: New file.
* Makefile.am (dist_patch_DATA): Add it.

* distro/base.scm (tar): Apply. `tar-gets-undeclared.patch'.

Makefile.am

@@ -46,7 +46,8 @@ dist_patch_DATA =				\
   distro/patches/m4-s_isdir.patch		\
   distro/patches/make-impure-dirs.patch		\
   distro/patches/findutils-absolute-paths.patch	\
-  distro/patches/readline-link-ncurses.patch
+  distro/patches/readline-link-ncurses.patch	\
+  distro/patches/tar-gets-undeclared.patch
 
 nobase_nodist_guilemodule_DATA = $(GOBJECTS)
 

distro/base.scm

@@ -163,6 +163,9 @@ substituting multiple occurrences of a string within a file.")
              (base32
               "0hbdkzmchq9ycr2x1pxqdcgdbaxksh8c6ac0jf75jajhcks6jlss"))))
    (build-system gnu-build-system)
+   (inputs `(("patch/gets" ,(search-patch "tar-gets-undeclared.patch"))))
+   (arguments
+    `(#:patches (list (assoc-ref %build-inputs "patch/gets"))))
    (description "GNU implementation of the `tar' archiver")
    (long-description
     "The Tar program provides the ability to create tar archives, as well as

distro/patches/tar-gets-undeclared.patch

@@ -0,0 +1,26 @@
+This patch is needed to allow builds with newer versions of
+the GNU libc (2.16+).
+
+This is a backport of this patch:
+
+commit 66712c23388e93e5c518ebc8515140fa0c807348
+Author: Eric Blake <eblake@redhat.com>
+Date:   Thu Mar 29 13:30:41 2012 -0600
+
+    stdio: don't assume gets any more
+    
+--- tar-1.26/gnu/stdio.in.h	2012-07-02 14:28:45.000000000 +0200
++++ tar-1.26/gnu/stdio.in.h	2012-07-02 14:28:50.000000000 +0200
+@@ -160,12 +160,6 @@ _GL_WARN_ON_USE (fflush, "fflush is not
+                  "use gnulib module fflush for portable POSIX compliance");
+ #endif
+ 
+-/* It is very rare that the developer ever has full control of stdin,
+-   so any use of gets warrants an unconditional warning.  Assume it is
+-   always declared, since it is required by C89.  */
+-#undef gets
+-_GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
+-
+ #if @GNULIB_FOPEN@
+ # if @REPLACE_FOPEN@
+ #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)