Fix a few crashes and leaks when cloning C strings.

* alloc.c, lisp.h (dupstring): New function.
* gtkutil.c (xg_get_font):
* term.c (tty_default_color_capabilities):
* xsettings.c (store_monospaced_changed)
(store_font_name_changed, parse_settings)
(read_and_apply_settings, init_gsettings, init_gconf): Use it.
This avoids some unlikely crashes due to accessing freed storage,
and avoids some minor memory leaks in the more-typical case.

1 files changed, 3 insertions, 11 deletions

diff --git a/src/term.c b/src/term.c
index 0c40c2d16b9..61a8d39d971 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2052,17 +2052,9 @@ tty_default_color_capabilities (struct tty_display_info *tty, bool save)
 
   if (save)
     {
-      xfree (default_orig_pair);
-      default_orig_pair = tty->TS_orig_pair ? xstrdup (tty->TS_orig_pair) : NULL;
-
-      xfree (default_set_foreground);
-      default_set_foreground = tty->TS_set_foreground ? xstrdup (tty->TS_set_foreground)
-                               : NULL;
-
-      xfree (default_set_background);
-      default_set_background = tty->TS_set_background ? xstrdup (tty->TS_set_background)
-                               : NULL;
-
+      dupstring (&default_orig_pair, tty->TS_orig_pair);
+      dupstring (&default_set_foreground, tty->TS_set_foreground);
+      dupstring (&default_set_background, tty->TS_set_background);
       default_max_colors = tty->TN_max_colors;
       default_max_pairs = tty->TN_max_pairs;
       default_no_color_video = tty->TN_no_color_video;