gnu: rcs: Fix build against gcc-5.4.0.

* gnu/local.mk (dist_patch_DATA): Add patch.
* gnu/packages/patches/rcs-5.9.4-noreturn.patch: New file.
* gnu/packages/version-control.scm (rcs)[source]: Applied patch.

Signed-off-by: Marius Bakke <mbakke@fastmail.com>

gnu/local.mk

@@ -891,6 +891,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/quickswitch-fix-dmenu-check.patch	\
   %D%/packages/patches/rapicorn-isnan.patch			\
   %D%/packages/patches/ratpoison-shell.patch			\
+  %D%/packages/patches/rcs-5.9.4-noreturn.patch			\
   %D%/packages/patches/readline-link-ncurses.patch		\
   %D%/packages/patches/readline-6.2-CVE-2014-2524.patch		\
   %D%/packages/patches/readline-7.0-mingw.patch			\

gnu/packages/patches/rcs-5.9.4-noreturn.patch

@@ -0,0 +1,94 @@
+Builds with GCC-5 failed due to misplaced `_Noreturn (__attribute__((noreturn)))`
+statement.
+
+Patch copied from upstream source repository:
+
+http://git.savannah.gnu.org/cgit/rcs.git/commit/?h=p&id=260704a9164dd34cf7128d6b1e88075ffa3be054
+
+Upstream bug URL:
+
+https://savannah.gnu.org/bugs/?49568
+
+commit 260704a9164dd34cf7128d6b1e88075ffa3be054
+Author: Thien-Thi Nguyen <ttn@gnu.org>
+Date:   Thu Jun 18 21:25:53 2015 +0200
+
+    [C slog] Move ‘exiting’ to beginning of func decl.
+    
+    Apparently, ‘gcc --std=c11’ does not abide the ‘exiting’
+    attribute appearing at the end of the func decl.
+    Reported by Romain Francoise.
+    See also <https://bugs.debian.org/778100>.
+    
+    * src/b-complain.h (generic_fatal, fatal_syntax, fatal_sys)
+    * src/b-fb.h (Ierror, Oerror)
+    * src/base.h (unexpected_EOF, thank_you_and_goodnight):
+    Move ‘exiting’ attribute to beginning of func decl.
+
+diff --git a/src/b-complain.h b/src/b-complain.h
+index 0ffd157..ea0ffc5 100644
+--- a/src/b-complain.h
++++ b/src/b-complain.h
+@@ -32,12 +32,14 @@ extern void generic_warn (char const *who, char const *fmt, ...)
+   printf_string (2, 3);
+ extern void generic_error (char const *who, char const *fmt, ...)
+   printf_string (2, 3);
++exiting
+ extern void generic_fatal (char const *who, char const *fmt, ...)
+-  printf_string (2, 3) exiting;
++  printf_string (2, 3);
++exiting
+ extern void fatal_syntax (size_t lno, char const *fmt, ...)
+-  printf_string (2, 3) exiting;
+-extern void fatal_sys (char const *who)
+-  exiting;
++  printf_string (2, 3);
++exiting
++extern void fatal_sys (char const *who);
+ 
+ /* Idioms.  Here, prefix P stands for "program" (general operation);
+    M for "manifestation"; R for "repository".  */
+diff --git a/src/b-fb.h b/src/b-fb.h
+index c9850e7..bf5eaf8 100644
+--- a/src/b-fb.h
++++ b/src/b-fb.h
+@@ -21,9 +21,11 @@
+ */
+ 
+ extern int change_mode (int fd, mode_t mode);
+-extern void Ierror (void) exiting;
++exiting
++extern void Ierror (void);
+ extern void testIerror (FILE *f);
+-extern void Oerror (void) exiting;
++exiting
++extern void Oerror (void);
+ extern void testOerror (FILE *o);
+ extern FILE *fopen_safer (char const *filename, char const *type);
+ extern void Ozclose (FILE **p);
+diff --git a/src/base.h b/src/base.h
+index 163ee09..5e7a9f8 100644
+--- a/src/base.h
++++ b/src/base.h
+@@ -755,8 +755,8 @@ int dorewrite (bool lockflag, int changed);
+ int donerewrite (int changed, time_t newRCStime);
+ void ORCSclose (void);
+ void ORCSerror (void);
+-void unexpected_EOF (void)
+-  exiting;
++exiting
++void unexpected_EOF (void);
+ void initdiffcmd (struct diffcmd *dc);
+ int getdiffcmd (struct fro *finfile, bool delimiter,
+                 FILE *foutfile, struct diffcmd *dc);
+@@ -831,8 +831,8 @@ char const *date2str (char const date[datesize],
+                       char datebuf[datesize + zonelenmax]);
+ 
+ /* rcsutil */
+-void thank_you_and_goodnight (int const how)
+-  exiting;
++exiting
++void thank_you_and_goodnight (int const how);
+ /* These are for ‘thank_you_and_goodnight’.  */
+ #define TYAG_ORCSERROR     (1 << 3)
+ #define TYAG_DIRTMPUNLINK  (1 << 2)

gnu/packages/version-control.scm

@@ -794,7 +794,8 @@ projects, from individuals to large-scale enterprise operations.")
                                  version ".tar.xz"))
              (sha256
               (base32
-               "1zsx7bb0rgvvvisiy4zlixf56ay8wbd9qqqcp1a1g0m1gl6mlg86"))))
+               "1zsx7bb0rgvvvisiy4zlixf56ay8wbd9qqqcp1a1g0m1gl6mlg86"))
+             (patches (search-patches "rcs-5.9.4-noreturn.patch"))))
     (build-system gnu-build-system)
     (native-inputs `(("ed" ,ed)))
     (home-page "http://www.gnu.org/software/rcs/")