* editfns.c: (TM_YEAR_BASE): Move up.

(Fdecode_time, Fencode_time): Use TM_YEAR_BASE instead of 1900.
(Fdecode_time): Cast tm_year to EMACS_INT, to avoid overflow when
int is narrower than EMACS_INT.
(Fcurrent_time_string): As with Fformat_time_string, report an
invalid time specification if the argument is invalid.  Also,
check for out-of-range time stamps.

diff --git a/src/ChangeLog b/src/ChangeLog
index a983cf00b773beb48110474fe1ee9e81f25eec00..ccc1f3923c45d0ad333b079d2f6a2164f0bbea90 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,23 @@
+2006-03-24  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * editfns.c: Do not use ctime, since it has undefined behavior
+       with out-of-range time stamps.  This fixes a bug where
+       (current-time-string '(2814749767106 0)) would make Emacs dump
+       core on 64-bit Solaris 8.  The fix is to use localtime+asctime
+       (checking for in-range results) instead of ctime.  Please see
+       <http://www.opengroup.org/austin/mailarchives/ag/msg09294.html>
+       for more details about this portability problem.
+       (TM_YEAR_BASE): Move up, so the changes below can use it.
+       (Fdecode_time, Fencode_time): Use TM_YEAR_BASE instead of 1900.
+       (Fdecode_time): Cast tm_year to EMACS_INT, to avoid overflow when
+       int is narrower than EMACS_INT.
+       (Fcurrent_time_string): As with Fformat_time_string, report an
+       invalid time specification if the argument is invalid.  Also,
+       check for out-of-range time stamps; this prevents a buffer overrun
+       that causes Emacs to dump core on 64-bit Solaris sparc, and it
+       preserves the historic behavior of always returning a fixed-size
+       string.
+
 2006-03-24  Kim F. Storm  <storm@cua.dk>
 
        * xterm.c (handle_one_xevent):

diff --git a/src/editfns.c b/src/editfns.c
index b621397eda338bf838da034c276a516a371a27f6..c4f8b95d81036dc56fa8494d8fc0228c0c478f56 100644 (file)
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -72,6 +72,8 @@ Boston, MA 02110-1301, USA.  */
 extern char **environ;
 #endif
 
+#define TM_YEAR_BASE 1900
+
 extern size_t emacs_strftimeu P_ ((char *, size_t, const char *,
                                   const struct tm *, int));
 static int tm_diff P_ ((struct tm *, struct tm *));
@@ -721,7 +723,7 @@ Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.  */)
   int orig_point = 0;
   int fwd;
   Lisp_Object prev_old, prev_new;
-  
+
   if (NILP (new_pos))
     /* Use the current point, and afterwards, set it.  */
     {
@@ -736,7 +738,7 @@ Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.  */)
 
   prev_old = make_number (XFASTINT (old_pos) - 1);
   prev_new = make_number (XFASTINT (new_pos) - 1);
-  
+
   if (NILP (Vinhibit_field_text_motion)
       && !EQ (new_pos, old_pos)
       && (!NILP (Fget_char_property (new_pos, Qfield, Qnil))
@@ -1722,7 +1724,7 @@ DOW and ZONE.)  */)
   XSETFASTINT (list_args[2], decoded_time->tm_hour);
   XSETFASTINT (list_args[3], decoded_time->tm_mday);
   XSETFASTINT (list_args[4], decoded_time->tm_mon + 1);
-  XSETINT (list_args[5], decoded_time->tm_year + 1900);
+  XSETINT (list_args[5], TM_YEAR_BASE + (EMACS_INT) decoded_time->tm_year);
   XSETFASTINT (list_args[6], decoded_time->tm_wday);
   list_args[7] = (decoded_time->tm_isdst)? Qt : Qnil;
 
@@ -1778,7 +1780,7 @@ usage: (encode-time SECOND MINUTE HOUR DAY MONTH YEAR &optional ZONE)  */)
   tm.tm_hour = XINT (args[2]);
   tm.tm_mday = XINT (args[3]);
   tm.tm_mon = XINT (args[4]) - 1;
-  tm.tm_year = XINT (args[5]) - 1900;
+  tm.tm_year = XINT (args[5]) - TM_YEAR_BASE;
   tm.tm_isdst = -1;
 
   if (CONSP (zone))
@@ -1844,11 +1846,16 @@ but this is considered obsolete.  */)
 {
   time_t value;
   char buf[30];
+  struct tm *tm;
   register char *tem;
 
   if (! lisp_time_argument (specified_time, &value, NULL))
-    value = -1;
-  tem = (char *) ctime (&value);
+    error ("Invalid time specification");
+  tm = localtime (&value);
+  if (! (tm && -999 - TM_YEAR_BASE <= tm->tm_year
+        && tm->tm_year <= 9999 - TM_YEAR_BASE))
+    error ("Specified time is not representable");
+  tem = asctime (tm);
 
   strncpy (buf, tem, 24);
   buf[24] = 0;
@@ -1856,8 +1863,6 @@ but this is considered obsolete.  */)
   return build_string (buf);
 }
 
-#define TM_YEAR_BASE 1900
-
 /* Yield A - B, measured in seconds.
    This function is copied from the GNU C Library.  */
 static int