Add --no-site-lisp option, make -Q use it. (Bug#5707)

* lisp/Makefile.in (EMACSOPT): Add --no-site-lisp.

* src/emacs.c (no_site_lisp): New int.
(USAGE1): Add --no-site-lisp, mention -Q uses it.
(main): Set no_site_lisp.
(standard_args): Add --no-site-lisp.

* src/lisp.h (no_site_lisp): New int.

* src/lread.c (init_lread): If no_site_lisp, don't re-add site-lisp
directories to Vload_path.

* etc/NEWS: Mention --no-site-lisp.

4 files changed, 45 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a32e7a28dc3..12768f3578b 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2011-01-07  Glenn Morris  <rgm@gnu.org>
+
+        * emacs.c (no_site_lisp): New int.
+        (USAGE1): Add --no-site-lisp, mention -Q uses it.
+        (main): Set no_site_lisp.
+        (standard_args): Add --no-site-lisp.
+        * lisp.h (no_site_lisp): New int.
+        * lread.c (init_lread): If no_site_lisp, don't re-add site-lisp
+        directories to Vload_path.
+
 2011-01-05  Andreas Schwab  <schwab@linux-m68k.org>
 
         * alloc.c (mark_stack): Use __builtin_unwind_init if available.
diff --git a/src/emacs.c b/src/emacs.c
index 59223336d45..2388146105b 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -231,6 +231,9 @@ int noninteractive1;
 /* Nonzero means Emacs was run in --quick mode.  */
 int inhibit_x_resources;
 
+/* Nonzero means remove site-lisp directories from load-path.  */
+int no_site_lisp;
+
 /* Name for the server started by the daemon.*/
 static char *daemon_name;
 
@@ -268,9 +271,11 @@ Initialization options:\n\
 --no-init-file, -q          load neither ~/.emacs nor default.el\n\
 --no-shared-memory, -nl     do not use shared memory\n\
 --no-site-file              do not load site-start.el\n\
+--no-site-lisp, -nsl        do not add site-lisp directories to load-path\n\
 --no-splash                 do not display a splash screen on startup\n\
 --no-window-system, -nw     do not communicate with X, ignoring $DISPLAY\n\
---quick, -Q                 equivalent to -q --no-site-file --no-splash\n\
+--quick, -Q                 equivalent to:\n\
+                              -q --no-site-file --no-site-lisp --no-splash\n\
 --script FILE               run FILE as an Emacs Lisp script\n\
 --terminal, -t DEVICE       use DEVICE for terminal I/O\n\
 --user, -u USER             load ~USER/.emacs instead of your own\n\
@@ -1341,6 +1346,9 @@ main (int argc, char **argv)
   no_loadup
     = argmatch (argv, argc, "-nl", "--no-loadup", 6, NULL, &skip_args);
 
+  no_site_lisp
+    = argmatch (argv, argc, "-nsl", "--no-site-lisp", 11, NULL, &skip_args);
+
 #ifdef HAVE_NS
   ns_alloc_autorelease_pool();
   if (!noninteractive)
@@ -1409,9 +1417,27 @@ main (int argc, char **argv)
              && argv[count_before + 1][1] == '-')
       argv[count_before + 1] = "-d";
 
+    if (! no_site_lisp)
+      {
+        if (argmatch (argv, argc, "-Q", "--quick", 3, NULL, &skip_args)
+            || argmatch (argv, argc, "-quick", 0, 2, NULL, &skip_args))
+          no_site_lisp = 1;
+      }
+
     /* Don't actually discard this arg.  */
     skip_args = count_before;
   }
+#else  /* !HAVE_X_WINDOWS */
+  if (! no_site_lisp)
+  {
+    int count_before = skip_args;
+
+    if (argmatch (argv, argc, "-Q", "--quick", 3, NULL, &skip_args)
+        || argmatch (argv, argc, "-quick", 0, 2, NULL, &skip_args))
+      no_site_lisp = 1;
+
+    skip_args = count_before;
+  }
 #endif
 
   /* argmatch must not be used after here,
@@ -1743,10 +1769,12 @@ const struct standard_args standard_args[] =
   { "-daemon", "--daemon", 99, 0 },
   { "-help", "--help", 90, 0 },
   { "-nl", "--no-loadup", 70, 0 },
+  { "-nsl", "--no-site-lisp", 65, 0 },
   /* -d must come last before the options handled in startup.el.  */
   { "-d", "--display", 60, 1 },
   { "-display", 0, 60, 1 },
   /* Now for the options handled in `command-line' (startup.el).  */
+  /* (Note that to imply -nsl, -Q is partially handled here.)  */
   { "-Q", "--quick", 55, 0 },
   { "-quick", 0, 55, 0 },
   { "-q", "--no-init-file", 50, 0 },
diff --git a/src/lisp.h b/src/lisp.h
index e02d559512c..eadbbacbff4 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1,6 +1,6 @@
 /* Fundamental definitions for GNU Emacs Lisp interpreter.
    Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 1998, 1999, 2000,
-                 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+                 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
                  Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
@@ -3225,6 +3225,9 @@ extern int noninteractive;
 /* Nonzero means don't load X resources or Windows Registry settings.  */
 extern int inhibit_x_resources;
 
+/* Nonzero means remove site-lisp directories from load-path.  */
+extern int no_site_lisp;
+
 /* Pipe used to send exit notification to the daemon parent at
    startup.  */
 extern int daemon_pipe[2];
@@ -3668,5 +3671,3 @@ extern Lisp_Object safe_alloca_unwind (Lisp_Object);
 
 #endif /* EMACS_LISP_H */
 
-/* arch-tag: 9b2ed020-70eb-47ac-94ee-e1c2a5107d5e
-   (do not change this comment) */
diff --git a/src/lread.c b/src/lread.c
index ea8c0416518..bc371fc02b0 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2,7 +2,7 @@
 
 Copyright (C) 1985, 1986, 1987, 1988, 1989, 1993, 1994, 1995, 1997,
   1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
-  2009, 2010  Free Software Foundation, Inc.
+  2009, 2010, 2011  Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -4086,7 +4086,7 @@ init_lread (void)
                         Vload_path = Fcons (tem, Vload_path);
                     }
                 }
-              if (!NILP (sitelisp))
+              if (!NILP (sitelisp) && !no_site_lisp)
                 Vload_path = nconc2 (Fnreverse (sitelisp), Vload_path);
             }
         }