Don't crash on bad user input.

* nsfns.m (ns_get_defaults_value): New function.
(Fns_get_resource, x_get_string_resource): Call ns_get_defaults_value.

* nsterm.h (ns_get_defaults_value): Declare.

* nsterm.m (ns_default): Call ns_get_defaults_value.

Fixes: debbugs:10103

src/ChangeLog

+2011-12-10  Jan Djärv  <jan.h.d@swipnet.se>
+
+	* nsfns.m (ns_get_defaults_value): New function (Bug#10103).
+	(Fns_get_resource, x_get_string_resource): Call ns_get_defaults_value.
+
+	* nsterm.h (ns_get_defaults_value): Declare.
+
+	* nsterm.m (ns_default): Call ns_get_defaults_value.
+
 2011-12-09  Eli Zaretskii  <eliz@gnu.org>
 
 	* xdisp.c (try_scrolling): Don't set scroll_down_p if dy is zero.

src/nsfns.m

@@ -1546,6 +1546,17 @@ Turn the input menu (an NSMenu) into a lisp list for tracking on lisp side
   return ret ? fname : Qnil;
 }
 
+const char *
+ns_get_defaults_value (const char *key)
+{
+  NSObject *obj = [[NSUserDefaults standardUserDefaults]
+                    objectForKey: [NSString stringWithUTF8String: key]];
+
+  if (!obj) return NULL;
+
+  return [[NSString stringWithFormat: @"%@", obj] UTF8String];
+}
+
 
 DEFUN ("ns-get-resource", Fns_get_resource, Sns_get_resource, 2, 2, 0,
        doc: /* Return the value of the property NAME of OWNER from the defaults database.
@@ -1560,9 +1571,7 @@ Turn the input menu (an NSMenu) into a lisp list for tracking on lisp side
   CHECK_STRING (name);
 /*fprintf (stderr, "ns-get-resource checking resource '%s'\n", SDATA (name)); */
 
-  value =[[[NSUserDefaults standardUserDefaults]
-            objectForKey: [NSString stringWithUTF8String: SDATA (name)]]
-           UTF8String];
+  value = ns_get_defaults_value (SDATA (name));
 
   if (value)
     return build_string (value);
@@ -2217,8 +2226,7 @@ and GNUstep implementations ("distributor-specific release
     /* --quick was passed, so this is a no-op.  */
     return NULL;
 
-  res = [[[NSUserDefaults standardUserDefaults] objectForKey:
-            [NSString stringWithUTF8String: toCheck]] UTF8String];
+  res = ns_get_defaults_value (toCheck);
   return !res ? NULL :
       (!strncasecmp (res, "YES", 3) ? "true" :
           (!strncasecmp (res, "NO", 2) ? "false" : res));

src/nsterm.h

@@ -760,6 +760,7 @@ extern void  ns_release_object (void *obj);
 extern void  ns_retain_object (void *obj);
 extern void *ns_alloc_autorelease_pool ();
 extern void ns_release_autorelease_pool ();
+extern const char *ns_get_defaults_value ();
 
 /* in nsmenu */
 extern void update_frame_tool_bar (FRAME_PTR f);

src/nsterm.m

@@ -3824,11 +3824,9 @@ Convert modifier code (see lisp.h) to lisp symbol
       Check a parameter value in user's preferences
    -------------------------------------------------------------------------- */
 {
-  const char *value;
+  const char *value = ns_get_defaults_value (parameter);
 
-  if ( (value =[[[NSUserDefaults standardUserDefaults]
-                   stringForKey: [NSString stringWithUTF8String: parameter]]
-                UTF8String]) )
+  if (value)
     {
       double f;
       char *pos;