distro: diffutils: Allow builds with glibc 2.16+.

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

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

Makefile.am

@@ -38,15 +38,16 @@ GOBJECTS = $(MODULES:%.scm=%.go)
 nobase_dist_guilemodule_DATA = $(MODULES)
 
 patchdir = $(pkgdatadir)/patches
-dist_patch_DATA =				\
-  distro/patches/binutils-ld-new-dtags.patch	\
-  distro/patches/guile-1.8-cpp-4.5.patch	\
-  distro/patches/m4-gets-undeclared.patch	\
-  distro/patches/m4-readlink-EINVAL.patch	\
-  distro/patches/m4-s_isdir.patch		\
-  distro/patches/make-impure-dirs.patch		\
-  distro/patches/findutils-absolute-paths.patch	\
-  distro/patches/readline-link-ncurses.patch	\
+dist_patch_DATA =					\
+  distro/patches/binutils-ld-new-dtags.patch		\
+  distro/patches/diffutils-gets-undeclared.patch	\
+  distro/patches/guile-1.8-cpp-4.5.patch		\
+  distro/patches/m4-gets-undeclared.patch		\
+  distro/patches/m4-readlink-EINVAL.patch		\
+  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/tar-gets-undeclared.patch
 
 nobase_nodist_guilemodule_DATA = $(GOBJECTS)

distro/base.scm

@@ -273,6 +273,9 @@ (define-public diffutils
              (base32
               "0jci0wv68025xd0s0rq4s5qxpx56dd9d730lka63qpzk1rfvfkxb"))))
    (build-system gnu-build-system)
+   (inputs `(("patch/gets"
+              ,(search-patch "diffutils-gets-undeclared.patch"))))
+   (arguments `(#:patches (list (assoc-ref %build-inputs "patch/gets"))))
    (description "Programs to find differences among text files")
    (long-description
     "GNU Diffutils is a package of several programs related to finding

distro/patches/diffutils-gets-undeclared.patch

@@ -0,0 +1,71 @@
+This patch is needed to allow builds with newer versions of
+the GNU libc (2.16+).
+
+
+commit 66712c23388e93e5c518ebc8515140fa0c807348
+Author: Eric Blake <eblake@redhat.com>
+Date:   Thu Mar 29 13:30:41 2012 -0600
+
+    stdio: don't assume gets any more
+    
+    Gnulib intentionally does not have a gets module, and now that C11
+    and glibc have dropped it, we should be more proactive about warning
+    any user on a platform that still has a declaration of this dangerous
+    interface.
+    
+    * m4/stdio_h.m4 (gl_STDIO_H, gl_STDIO_H_DEFAULTS): Drop gets
+    support.
+    * modules/stdio (Makefile.am): Likewise.
+    * lib/stdio-read.c (gets): Likewise.
+    * tests/test-stdio-c++.cc: Likewise.
+    * m4/warn-on-use.m4 (gl_WARN_ON_USE_PREPARE): Fix comment.
+    * lib/stdio.in.h (gets): Make warning occur in more places.
+    * doc/posix-functions/gets.texi (gets): Update documentation.
+    Reported by Christer Solskogen.
+    
+    Signed-off-by: Eric Blake <eblake@redhat.com>
+
+diff --git a/lib/stdio.in.h b/lib/stdio.in.h
+index aa7b599..c377b6e 100644
+--- a/lib/stdio.in.h
++++ b/lib/stdio.in.h
+@@ -698,22 +698,11 @@ _GL_WARN_ON_USE (getline, "getline is unportable - "
+ # endif
+ #endif
+ 
+-#if @GNULIB_GETS@
+-# if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
+-#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+-#   undef gets
+-#   define gets rpl_gets
+-#  endif
+-_GL_FUNCDECL_RPL (gets, char *, (char *s) _GL_ARG_NONNULL ((1)));
+-_GL_CXXALIAS_RPL (gets, char *, (char *s));
+-# else
+-_GL_CXXALIAS_SYS (gets, char *, (char *s));
+-#  undef gets
+-# endif
+-_GL_CXXALIASWARN (gets);
+ /* 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.  */
++   so any use of gets warrants an unconditional warning; besides, C11
++   removed it.  */
++#undef gets
++#if HAVE_RAW_DECL_GETS
+ _GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
+ #endif
+ 
+@@ -1053,9 +1042,9 @@ _GL_WARN_ON_USE (snprintf, "snprintf is unportable - "
+ # endif
+ #endif
+ 
+-/* Some people would argue that sprintf should be handled like gets
+-   (for example, OpenBSD issues a link warning for both functions),
+-   since both can cause security holes due to buffer overruns.
++/* Some people would argue that all sprintf uses should be warned about
++   (for example, OpenBSD issues a link warning for it),
++   since it can cause security holes due to buffer overruns.
+    However, we believe that sprintf can be used safely, and is more
+    efficient than snprintf in those safe cases; and as proof of our
+    belief, we use sprintf in several gnulib modules.  So this header