glib: Don’t use time(NULL) to get current time

Use either g_get_real_time() or g_date_time_new_now_local(). This means
we don’t need to worry about time_t being 32b in future (the year 2038
problem), and it makes the need for error handling a bit more explicit.
Improve the error handling in several cases.

Based on a patch by Niels De Graef
(https://gitlab.gnome.org/GNOME/glib/merge_requests/142).

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://gitlab.gnome.org/GNOME/glib/issues/1402

gio/gdbusauthmechanismsha1.c

@@ -603,7 +603,7 @@ keyring_generate_entry (const gchar  *cookie_context,
   gchar **lines;
   gint max_line_id;
   GString *new_contents;
-  guint64 now;
+  gint64 now;
   gboolean have_id;
   gint use_id;
   gchar *use_cookie;
@@ -658,7 +658,7 @@ keyring_generate_entry (const gchar  *cookie_context,
     }
 
   new_contents = g_string_new (NULL);
-  now = (guint64) time (NULL);
+  now = g_get_real_time () / G_USEC_PER_SEC;
   changed_file = FALSE;
 
   max_line_id = 0;
@@ -672,7 +672,7 @@ keyring_generate_entry (const gchar  *cookie_context,
           gchar **tokens;
           gchar *endp;
           gint line_id;
-          guint64 line_when;
+          gint64 line_when;
           gboolean keep_entry;
 
           if (line[0] == '\0')
@@ -807,9 +807,9 @@ keyring_generate_entry (const gchar  *cookie_context,
       g_free (raw_cookie);
 
       g_string_append_printf (new_contents,
-                              "%d %" G_GUINT64_FORMAT " %s\n",
+                              "%d %" G_GINT64_FORMAT " %s\n",
                               *out_id,
-                              (guint64) time (NULL),
+                              g_get_real_time () / G_USEC_PER_SEC,
                               *out_cookie);
       changed_file = TRUE;
     }

gio/glocalfile.c

@@ -1909,7 +1909,7 @@ g_local_file_trash (GFile         *file,
   int i;
   char *data;
   gboolean is_homedir_trash;
-  char delete_time[32];
+  char *delete_time = NULL;
   int fd;
   GStatBuf trash_stat, global_stat;
   char *dirname, *globaldir;
@@ -2137,16 +2137,17 @@ g_local_file_trash (GFile         *file,
   g_free (topdir);
   
   {
-    time_t t;
-    struct tm now;
-    t = time (NULL);
-    localtime_r (&t, &now);
-    delete_time[0] = 0;
-    strftime(delete_time, sizeof (delete_time), "%Y-%m-%dT%H:%M:%S", &now);
+    GDateTime *now = g_date_time_new_now_local ();
+    if (now != NULL)
+      delete_time = g_date_time_format (now, "%Y-%m-%dT%H:%M:%S");
+    else
+      delete_time = g_strdup ("9999-12-31T23:59:59");
+    g_date_time_unref (now);
   }
 
   data = g_strdup_printf ("[Trash Info]\nPath=%s\nDeletionDate=%s\n",
 			  original_name_escaped, delete_time);
+  g_free (delete_time);
 
   g_file_set_contents (infofile, data, -1, NULL);
 

gio/tests/gdbus-example-peer.c

@@ -273,7 +273,8 @@ main (int argc, char *argv[])
                "Negotiated capabilities: unix-fd-passing=%d\n",
                g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING);
 
-      greeting = g_strdup_printf ("Hey, it's %" G_GUINT64_FORMAT " already!", (guint64) time (NULL));
+      greeting = g_strdup_printf ("Hey, it's %" G_GINT64_FORMAT " already!",
+                                  g_get_real_time () / G_USEC_PER_SEC);
       value = g_dbus_connection_call_sync (connection,
                                            NULL, /* bus_name */
                                            "/org/gtk/GDBus/TestObject",

gio/tests/gdbus-example-unix-fd-client.c

@@ -74,16 +74,14 @@ on_name_appeared (GDBusConnection *connection,
     }
   else
     {
-      gchar now_buf[256];
-      time_t now;
+      gchar *now_buf = NULL;
       gssize len;
       gchar *str;
+      GDateTime *now = g_date_time_new_now_local ();
 
-      now = time (NULL);
-      strftime (now_buf,
-                sizeof now_buf,
-                "%Y-%m-%d %H:%M:%S",
-                localtime (&now));
+      g_assert_nonnull (now);
+      now_buf = g_date_time_format (now, "%Y-%m-%d %H:%M:%S");
+      g_date_time_unref (now);
 
       str = g_strdup_printf ("On %s, gdbus-example-unix-fd-client with pid %d was here!\n",
                              now_buf,
@@ -95,6 +93,7 @@ on_name_appeared (GDBusConnection *connection,
       g_print ("Wrote the following on server's stdout:\n%s", str);
 
       g_free (str);
+      g_free (now_buf);
       exit (0);
     }
 }

glib/gdate.c

@@ -1387,7 +1387,10 @@ g_date_set_parse (GDate       *d,
  *
  * To set the value of a date to the current day, you could write:
  * |[<!-- language="C" -->
- *  g_date_set_time_t (date, time (NULL)); 
+ *  time_t now = time (NULL);
+ *  if (now == (time_t) -1)
+ *    // handle the error
+ *  g_date_set_time_t (date, now);
  * ]|
  *
  * Since: 2.10

glib/tests/date.c

@@ -89,11 +89,14 @@ test_dates (void)
 {
   GDate *d;
   GTimeVal tv;
+  time_t now;
 
   d = g_date_new ();
 
   /* today */
-  g_date_set_time (d, time (NULL));
+  now = time (NULL);
+  g_assert_cmpint (now, !=, (time_t) -1);
+  g_date_set_time (d, now);
   g_assert (g_date_valid (d));
 
   /* Unix epoch */

glib/tests/gdatetime.c

@@ -112,6 +112,7 @@ test_GDateTime_new_from_unix (void)
 
   memset (&tm, 0, sizeof (tm));
   t = time (NULL);
+  g_assert_cmpint (t, !=, (time_t) -1);
   get_localtime_tm (t, &tm);
 
   dt = g_date_time_new_from_unix_local (t);
@@ -787,6 +788,7 @@ test_GDateTime_to_unix (void)
   time_t     t;
 
   t = time (NULL);
+  g_assert_cmpint (t, !=, (time_t) -1);
   dt = g_date_time_new_from_unix_local (t);
   g_assert_cmpint (g_date_time_to_unix (dt), ==, t);
   g_date_time_unref (dt);
@@ -1283,6 +1285,7 @@ test_GDateTime_to_utc (void)
   struct tm  tm;
 
   t = time (NULL);
+  g_assert_cmpint (t, !=, (time_t) -1);
 #ifdef HAVE_GMTIME_R
   gmtime_r (&t, &tm);
 #else
@@ -1362,6 +1365,7 @@ GDateTime *__dt = g_date_time_new_local (2009, 10, 24, 0, 0, 0);\
    * that of the generated timezone.
    */
   t = time (NULL);
+  g_assert_cmpint (t, !=, (time_t) -1);
   memset (&tt, 0, sizeof(tt));
   get_localtime_tm (t, &tt);
   tt.tm_year = 2009 - 1900;