[seed] Bugfix: Made Seed.argv check for invalid array parameter

[Alan Knowles <alank src gnome org>]

commit 8012eea197d4366bd7ec72cc57aaf0db897509ec
Author: Peter Rustler <peter rustler basyskom com>
Date:   Mon Dec 7 16:52:41 2015 +0000

    Bugfix: Made Seed.argv check for invalid array parameter
    
    Seed.argv will drop a segfault when you access the array out of
    range.
    
    This patch add checking for valid value of array index.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759172

 libseed/seed-builtins.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/libseed/seed-builtins.c b/libseed/seed-builtins.c
index b5b14fc..3988a3d 100644
--- a/libseed/seed-builtins.c
+++ b/libseed/seed-builtins.c
@@ -469,7 +469,7 @@ seed_argv_get_property (JSContextRef ctx,
   SeedArgvPrivates *priv;
   gchar *cproperty_name;
   gsize length;
-  guint index;
+  gint index;
 
   priv = JSObjectGetPrivate (object);
   if (!priv->argc)
@@ -483,7 +483,14 @@ seed_argv_get_property (JSContextRef ctx,
       return seed_value_from_int (ctx, priv->argc, exception);
     }
   index = atoi (cproperty_name);
-  return seed_value_from_string (ctx, priv->argv[index], exception);
+  if (index >= 0 && index < priv->argc) {
+         return seed_value_from_string (ctx, priv->argv[index], exception);
+  } else {
+         seed_make_exception (ctx, exception, "ArgumentError",
+                         "ArgumentCount "
+                         "%d, got %d", priv->argc, index);
+         return JSValueMakeNull (ctx);
+  }
 }
 
 JSClassDefinition seed_argv_def = {