Install update-game-score only on request

Most distributions do not install update-game-score properly
due to setuid/setgid complications, so install it only when
the installer specifies a user or group (Bug#25895).
* .gitattributes: Remove lib-src/update-game-score.exe.manifest.
* Makefile.in (gameuser, gamegroup, use_gamedir, PATH_GAME):
New vars.
(epaths-force): Use PATH_GAME.
(uninstall): Remove snake-scores and tetris-scores only if shared.
* configure.ac: Default --with-gameuser to 'no'.
(UPDATE_MANIFEST): Remove.
* etc/NEWS: Mention this.
* lib-src/Makefile.in (UPDATE_MANIFEST): Remove.
(use_gamedir): New macro.
(UTILITIES): Remove update-game-score unless use_gamedir.
(SCRIPTS): Remove $(UPDATE_MANIFEST).
($(DESTDIR)${archlibdir}): Install game directory program and data
only if use_gamedir.
* lib-src/update-game-score.exe.manifest: Remove, as
update-game-score is no longer installed on MS-Windows.
* lisp/play/gamegrid.el (gamegrid-add-score-with-update-game-score):
Use auxiliary program only if setuid or setgid.
* make-dist: Do not distribute update-game-score.exe.manifest.
* src/callproc.c (init_callproc):
Set Vshared_game_score_directory based on PATH_GAME, not DOS_NT.
(syms_of_callproc): Remove unnecessary initialization of
Vshared_game_score_directory.

9 files changed, 63 insertions, 81 deletions

diff --git a/.gitattributes b/.gitattributes
index 22cea3dc1e3..59cc2eded5d 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -24,7 +24,6 @@ admin/charsets/mapfiles/PTCP154 whitespace=cr-at-eol
 leim/MISC-DIC/cangjie-table.b5 whitespace=cr-at-eol
 leim/MISC-DIC/cangjie-table.cns whitespace=cr-at-eol
 leim/MISC-DIC/pinyin.map whitespace=cr-at-eol
-lib-src/update-game-score.exe.manifest whitespace=cr-at-eol
 nt/nmake.defs whitespace=cr-at-eol
 test/etags/c-src/dostorture.c whitespace=cr-at-eol
 test/etags/cp-src/c.C whitespace=cr-at-eol
diff --git a/Makefile.in b/Makefile.in
index 82fb91fd9cd..18251b41043 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -266,8 +266,15 @@ archlibdir=@archlibdir@
 # Where to put the etc/DOC file.
 etcdocdir=@etcdocdir@
 
-# Where to install Emacs game score files.
+# User or group of the auxiliary program update-game-score, which is
+# installed on platforms with a game directory shared by multiple users.
+# On other platforms Emacs can update the score files itself.
+gameuser=@gameuser@
+gamegroup=@gamegroup@
+# Where to install game score files, if gameuser or gamegroup is nonempty.
 gamedir=@gamedir@
+# Nonempty if and only if a shared gamedir is used.
+use_gamedir=$(gameuser)$(gamegroup)
 
 # ==================== Utility Programs for the Build ====================
 
@@ -334,6 +341,9 @@ etc-emacsver:
 	  ${srcdir}/build-aux/move-if-change emacsver.tex.$$$$ \
 	  ${srcdir}/etc/refcards/emacsver.tex
 
+# The shared gamedir name as a C string literal, or a null ptr if not in use.
+PATH_GAME = $(if $(use_gamedir),"$(gamedir)",((char const *) 0))
+
 # Generate epaths.h from epaths.in.  This target is invoked by 'configure'.
 # See comments in configure.ac for why it is done this way, as opposed
 # to just letting configure generate epaths.h from epaths.in in a
@@ -359,7 +369,7 @@ epaths-force:
 	  -e 's;\(#.*PATH_DATA\).*$$;\1 "${etcdir}";'			\
 	  -e 's;\(#.*PATH_BITMAPS\).*$$;\1 "${bitmapdir}";'		\
 	  -e 's;\(#.*PATH_X_DEFAULTS\).*$$;\1 "${x_default_search_path}";' \
-	  -e 's;\(#.*PATH_GAME\).*$$;\1 "${gamedir}";' \
+	  -e 's;\(#.*PATH_GAME\).*$$;\1 $(PATH_GAME);'			\
 	  -e 's;\(#.*PATH_DOC\).*$$;\1 "${etcdocdir}";') &&		\
 	${srcdir}/build-aux/move-if-change epaths.h.$$$$ src/epaths.h
 
@@ -811,10 +821,12 @@ uninstall: uninstall-$(NTDIR) uninstall-doc
 	-rm -f "$(DESTDIR)${desktopdir}/${EMACS_NAME}.desktop"
 	-rm -f "$(DESTDIR)${appdatadir}/${EMACS_NAME}.appdata.xml"
 	-rm -f "$(DESTDIR)$(systemdunitdir)/${EMACS_NAME}.service"
+  ifneq (,$(use_gamedir))
 	for file in snake-scores tetris-scores; do \
 	  file="$(DESTDIR)${gamedir}/$${file}"; \
 	  [ -s "$${file}" ] || rm -f "$$file"; \
 	done
+  endif
 
 ### Windows-specific uninstall target for removing programs produced
 ### in nt/, and its Posix do-nothing shadow.
diff --git a/configure.ac b/configure.ac
index ba944e6cebd..4d9ba9636d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -402,12 +402,9 @@ AC_ARG_WITH(gameuser,dnl
 		An argument prefixed by ':' specifies a group instead.])])
 gameuser=
 gamegroup=
-# We don't test if we can actually chown/chgrp here, because configure
-# may run without root privileges.  lib-src/Makefile.in will handle
-# any errors due to missing user/group gracefully.
 case ${with_gameuser} in
-  no) ;;
-  "" | yes) gamegroup=games ;;
+  '' | no) ;;
+  yes) gamegroup=games ;;
   :*) gamegroup=${with_gameuser#:} ;;
   *) gameuser=${with_gameuser} ;;
 esac
@@ -1966,7 +1963,6 @@ CLIENTRES=
 CLIENTW=
 W32_RES_LINK=
 EMACS_MANIFEST=
-UPDATE_MANIFEST=
 if test "${with_w32}" != no; then
   case "${opsys}" in
     cygwin)
@@ -2034,7 +2030,6 @@ if test "${HAVE_W32}" = "yes"; then
     # the rc file), not a linker script.
     W32_RES_LINK="-Wl,emacs.res"
   else
-    UPDATE_MANIFEST=update-game-score.exe.manifest
     W32_OBJ="$W32_OBJ w32.o w32console.o w32heap.o w32inevt.o w32proc.o"
     W32_LIBS="$W32_LIBS -lwinmm -lgdi32 -lcomdlg32"
     W32_LIBS="$W32_LIBS -lmpr -lwinspool -lole32 -lcomctl32 -lusp10"
@@ -2054,7 +2049,6 @@ AC_SUBST(W32_OBJ)
 AC_SUBST(W32_LIBS)
 AC_SUBST(EMACSRES)
 AC_SUBST(EMACS_MANIFEST)
-AC_SUBST(UPDATE_MANIFEST)
 AC_SUBST(CLIENTRES)
 AC_SUBST(CLIENTW)
 AC_SUBST(W32_RES_LINK)
@@ -5432,7 +5426,7 @@ AC_SUBST(SUBDIR_MAKEFILES_IN)
 dnl You might wonder (I did) why epaths.h is generated by running make,
 dnl rather than just letting configure generate it from epaths.in.
 dnl One reason is that the various paths are not fully expanded (see above);
-dnl eg gamedir=${prefix}/var/games/emacs.
+dnl e.g., gamedir='${localstatedir}/games/emacs'.
 dnl Secondly, the GNU Coding standards require that one should be able
 dnl to run 'make prefix=/some/where/else' and override the values set
 dnl by configure.  This also explains the 'move-if-change' test and
diff --git a/etc/NEWS b/etc/NEWS
index f0df0a70caa..cd829bf5291 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -65,6 +65,11 @@ emacs-version and erc-cmd-SV functions, and the leave the following
 variables nil: emacs-build-system, emacs-build-time,
 erc-emacs-build-time.
 
+** The configure option '--with-gameuser' now defaults to 'no',
+as this appears to be the most common configuration in practice.
+When it is 'no', the shared game directory and the auxiliary program
+update-game-score are no longer needed and are not installed.
+
 ** Emacs no longer works on IRIX.  We expect that Emacs users are not
 affected by this, as SGI stopped supporting IRIX in December 2013.
 
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index 88f62805765..d0aa9cc7c27 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -40,7 +40,6 @@ C_SWITCH_MACHINE=@C_SWITCH_MACHINE@
 PROFILING_CFLAGS = @PROFILING_CFLAGS@
 WARN_CFLAGS = @WARN_CFLAGS@
 WERROR_CFLAGS = @WERROR_CFLAGS@
-UPDATE_MANIFEST = @UPDATE_MANIFEST@
 
 # Program name transformation.
 TRANSFORM = @program_transform_name@
@@ -130,9 +129,15 @@ abs_top_srcdir=@abs_top_srcdir@
 # to '../configure'.
 archlibdir=@archlibdir@
 
-gamedir=@gamedir@
+# User or group of the auxiliary program update-game-score, which is
+# installed on platforms with a game directory shared by multiple users.
+# On other platforms Emacs can update the score files itself.
 gameuser=@gameuser@
 gamegroup=@gamegroup@
+# Where to install game score files, if gameuser or gamegroup is nonempty.
+gamedir=@gamedir@
+# Nonempty if and only if a shared gamedir is used.
+use_gamedir=$(gameuser)$(gamegroup)
 
 # ==================== Utility Programs for the Build =================
 
@@ -156,13 +161,13 @@ INSTALLABLES = etags${EXEEXT} ctags${EXEEXT} emacsclient${EXEEXT} $(CLIENTW) \
 # Things that Emacs runs internally, or during the build process,
 #  which should not be installed in bindir.
 UTILITIES = profile${EXEEXT} movemail${EXEEXT} hexl${EXEEXT} \
-            update-game-score${EXEEXT}
+            $(and $(use_gamedir), update-game-score${EXEEXT})
 
 DONT_INSTALL= make-docfile${EXEEXT}
 
 # Like UTILITIES, but they're not system-dependent, and should not be
 #  deleted by the distclean target.
-SCRIPTS= rcs2log $(UPDATE_MANIFEST)
+SCRIPTS= rcs2log
 
 # All files that are created by the linker, i.e., whose names end in ${EXEEXT}.
 EXE_FILES = ${INSTALLABLES} ${UTILITIES} ${DONT_INSTALL}
@@ -258,9 +263,6 @@ maybe-blessmail: $(BLESSMAIL_TARGET)
 
 ## Install the internal utilities.  Until they are installed, we can
 ## just run them directly from lib-src.
-## If the chown/chmod commands fail, that is not a big deal.
-## update-game-score will detect at runtime that it is not setuid,
-## and handle things accordingly.
 $(DESTDIR)${archlibdir}: all
 	@echo
 	@echo "Installing utilities run internally by Emacs."
@@ -272,28 +274,22 @@ $(DESTDIR)${archlibdir}: all
 	      "$(DESTDIR)${archlibdir}/$$file" || exit; \
 	  done ; \
         fi
-	umask 022 && ${MKDIR_P} "$(DESTDIR)${gamedir}" && \
+  ifneq (,$(use_gamedir))
+	umask 022 && ${MKDIR_P} "$(DESTDIR)${gamedir}"
 	touch "$(DESTDIR)${gamedir}/snake-scores" \
 	      "$(DESTDIR)${gamedir}/tetris-scores"
-ifneq ($(gameuser),)
-	if chown ${gameuser} \
-	     "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}" && \
-	   chmod u+s,go-r \
-	     "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"; \
-	then \
-	  chown ${gameuser} "$(DESTDIR)${gamedir}" && \
-	  chmod u=rwx,g=rx,o=rx "$(DESTDIR)${gamedir}"; \
-	fi
-else ifneq ($(gamegroup),)
-	if chgrp ${gamegroup} \
-	     "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}" && \
-	   chmod g+s,o-r \
-	     "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"; \
-	then \
-	  chgrp ${gamegroup} "$(DESTDIR)${gamedir}" && \
-	  chmod u=rwx,g=rwx,o=rx "$(DESTDIR)${gamedir}"; \
-	fi
-endif
+    ifneq (,$(gameuser))
+	chown ${gameuser} "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
+	chmod u+s,go-r "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
+	chown ${gameuser} "$(DESTDIR)${gamedir}"
+	chmod u=rwx,g=rx,o=rx "$(DESTDIR)${gamedir}"
+    else
+	chgrp ${gamegroup} "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
+	chmod g+s,o-r "$(DESTDIR)${archlibdir}/update-game-score${EXEEXT}"
+	chgrp ${gamegroup} "$(DESTDIR)${gamedir}"
+	chmod u=rwx,g=rwx,o=rx "$(DESTDIR)${gamedir}"
+    endif
+  endif
 	exp_archlibdir=`cd "$(DESTDIR)${archlibdir}" && /bin/pwd` && \
 	if [ "$$exp_archlibdir" != "`cd ${srcdir} && /bin/pwd`" ]; then \
 	  for file in ${SCRIPTS}; do \
diff --git a/lib-src/update-game-score.exe.manifest b/lib-src/update-game-score.exe.manifest
deleted file mode 100644
index 1db836bec6b..00000000000
--- a/lib-src/update-game-score.exe.manifest
+++ /dev/null
@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

-<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">

-  <v3:trustInfo xmlns:v3="urn:schemas-microsoft-com:asm.v3">

-    <v3:security>

-      <v3:requestedPrivileges>

-	<v3:requestedExecutionLevel level="asInvoker" />

-      </v3:requestedPrivileges>

-    </v3:security>

-  </v3:trustInfo>

-</assembly>

diff --git a/lisp/play/gamegrid.el b/lisp/play/gamegrid.el
index b0ccbd3b63d..0386a89b3a4 100644
--- a/lisp/play/gamegrid.el
+++ b/lisp/play/gamegrid.el
@@ -475,17 +475,19 @@ FILE is created there."
 ;;        update FILE.  This is for the case that a user has installed
 ;;        a game on her own.
 ;;
-;;     4. "update-game-score" is not setgid/setuid.  Use it to
-;;        create/update FILE in the user's home directory.  There is
-;;        presumably no shared game directory.
+;;     4. "update-game-score" does not exist or is not setgid/setuid.
+;;        Create/update FILE in the user's home directory, without
+;;        using "update-game-score".  There is presumably no shared
+;;        game directory.
 
 (defvar gamegrid-shared-game-dir)
 
 (defun gamegrid-add-score-with-update-game-score (file score)
   (let ((gamegrid-shared-game-dir
-	 (not (zerop (logand (file-modes
-			      (expand-file-name "update-game-score"
-						exec-directory))
+	 (not (zerop (logand (or (file-modes
+				  (expand-file-name "update-game-score"
+						    exec-directory))
+				  0)
 			     #o6000)))))
     (cond ((file-name-absolute-p file)
 	   (gamegrid-add-score-insecure file score))
@@ -497,23 +499,12 @@ FILE is created there."
 	    (expand-file-name file shared-game-score-directory) score))
 	  ;; Else: Add the score to a score file in the user's home
 	  ;; directory.
-	  (gamegrid-shared-game-dir
-	   ;; If `gamegrid-shared-game-dir' is non-nil, then
-	   ;; "update-gamescore" program is setuid, so don't use it.
-	   (unless (file-exists-p
-		    (directory-file-name gamegrid-user-score-file-directory))
-	     (make-directory gamegrid-user-score-file-directory t))
-	   (gamegrid-add-score-insecure file score
-					gamegrid-user-score-file-directory))
 	  (t
 	   (unless (file-exists-p
 		    (directory-file-name gamegrid-user-score-file-directory))
 	     (make-directory gamegrid-user-score-file-directory t))
-	   (let ((f (expand-file-name file
-				      gamegrid-user-score-file-directory)))
-	     (unless (file-exists-p f)
-	       (write-region "" nil f nil 'silent nil 'excl))
-	     (gamegrid-add-score-with-update-game-score-1 file f score))))))
+	   (gamegrid-add-score-insecure file score
+					gamegrid-user-score-file-directory)))))
 
 (defun gamegrid-add-score-with-update-game-score-1 (file target score)
   (let ((default-directory "/")
diff --git a/make-dist b/make-dist
index 41203b20aa7..e85a2d667b2 100755
--- a/make-dist
+++ b/make-dist
@@ -459,7 +459,6 @@ echo "Making links to 'lib-src'"
  ln [a-zA-Z]*.[ch] ../${tempdir}/lib-src
  ln ChangeLog.*[0-9] Makefile.in README ../${tempdir}/lib-src
  ln rcs2log ../${tempdir}/lib-src
- ln update-game-score.exe.manifest ../${tempdir}/lib-src)
 
 echo "Making links to 'm4'"
 (cd m4
diff --git a/src/callproc.c b/src/callproc.c
index 08fa6e97722..05048576ce9 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1584,13 +1584,14 @@ init_callproc (void)
   sh = getenv ("SHELL");
   Vshell_file_name = build_string (sh ? sh : "/bin/sh");
 
-#ifdef DOS_NT
-  Vshared_game_score_directory = Qnil;
-#else
-  Vshared_game_score_directory = build_unibyte_string (PATH_GAME);
-  if (NILP (Ffile_accessible_directory_p (Vshared_game_score_directory)))
-    Vshared_game_score_directory = Qnil;
-#endif
+  Lisp_Object gamedir = Qnil;
+  if (PATH_GAME)
+    {
+      Lisp_Object path_game = build_unibyte_string (PATH_GAME);
+      if (file_accessible_directory_p (path_game))
+	gamedir = path_game;
+    }
+  Vshared_game_score_directory = gamedir;
 }
 
 void
@@ -1661,11 +1662,6 @@ includes this.  */);
   DEFVAR_LISP ("shared-game-score-directory", Vshared_game_score_directory,
 	       doc: /* Directory of score files for games which come with GNU Emacs.
 If this variable is nil, then Emacs is unable to use a shared directory.  */);
-#ifdef DOS_NT
-  Vshared_game_score_directory = Qnil;
-#else
-  Vshared_game_score_directory = build_string (PATH_GAME);
-#endif
 
   DEFVAR_LISP ("initial-environment", Vinitial_environment,
 	       doc: /* List of environment variables inherited from the parent process.