'temacs -nw' should not call missing functions

[gnu-emacs] / src / editfns.c

diff --git a/src/editfns.c b/src/editfns.c
index 430c4c91fb3b175841afbe101217619e028e1d62..37f85b3ada33bc87fc9215504c6cb8d84cd435b3 100644 (file)
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -1,6 +1,6 @@
 /* Lisp functions pertaining to editing.
 
-Copyright (C) 1985-1987, 1989, 1993-2014 Free Software Foundation, Inc.
+Copyright (C) 1985-1987, 1989, 1993-2015 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -93,6 +93,17 @@ static char const *initial_tz;
    It is OK (though a bit slower) if the user chooses this value.  */
 static char dump_tz_string[] = "TZ=UtC0";
 
+/* The cached value of Vsystem_name.  This is used only to compare it
+   to Vsystem_name, so it need not be visible to the GC.  */
+static Lisp_Object cached_system_name;
+
+static void
+init_and_cache_system_name (void)
+{
+  init_system_name ();
+  cached_system_name = Vsystem_name;
+}
+
 void
 init_editfns (void)
 {
@@ -102,7 +113,7 @@ init_editfns (void)
   Lisp_Object tem;
 
   /* Set up system_name even when dumping.  */
-  init_system_name ();
+  init_and_cache_system_name ();
 
 #ifndef CANNOT_DUMP
   /* When just dumping out, set the time zone to a known unlikely value
@@ -1365,6 +1376,8 @@ DEFUN ("system-name", Fsystem_name, Ssystem_name, 0, 0, 0,
        doc: /* Return the host name of the machine you are running on, as a string.  */)
   (void)
 {
+  if (EQ (Vsystem_name, cached_system_name))
+    init_and_cache_system_name ();
   return Vsystem_name;
 }
 
@@ -4965,6 +4978,7 @@ functions if all the text being accessed has this property.  */);
 
   DEFVAR_LISP ("system-name", Vsystem_name,
               doc: /* The host name of the machine Emacs is running on.  */);
+  Vsystem_name = cached_system_name = Qnil;
 
   DEFVAR_LISP ("user-full-name", Vuser_full_name,
               doc: /* The full name of the user logged in.  */);