[seed] Minor build warning fix

[Danilo Cesar Lemes de Paula <danilocesar src gnome org>]

commit 7b77f7dfbbda83cced2be8cf42349dc150250715
Author: Danilo Cesar Lemes de Paula <danilo cesar collabora co uk>
Date:   Mon Aug 15 13:17:13 2016 -0300

    Minor build warning fix

 libseed/seed-engine.c |    2 +-
 libseed/seed-types.c  |    6 +++---
 libseed/seed-types.h  |   11 +++++++++++
 3 files changed, 15 insertions(+), 4 deletions(-)
---
diff --git a/libseed/seed-engine.c b/libseed/seed-engine.c
index 3c524f5..a9a9b64 100644
--- a/libseed/seed-engine.c
+++ b/libseed/seed-engine.c
@@ -783,7 +783,7 @@ seed_gobject_method_invoked(JSContextRef ctx,
 
     if (force_return_array) {
         if (n_out_args + !!(tag != GI_TYPE_TAG_VOID) > 1) {
-            retval_ref = JSObjectMakeArray(ctx, NULL, NULL, NULL);
+            retval_ref = JSObjectMakeArray(ctx, 0, NULL, NULL);
             use_return_as_out = 1;
         }
     }
diff --git a/libseed/seed-types.c b/libseed/seed-types.c
index 722f265..7cfc479 100644
--- a/libseed/seed-types.c
+++ b/libseed/seed-types.c
@@ -318,7 +318,7 @@ seed_array_from_zero_terminated_c_array(JSContextRef ctx,
                                         GITypeInfo* param_info,
                                         JSValueRef* exception)
 {
-    JSObjectRef ret;
+    JSValueRef ret;
     GITypeTag element_type;
     GArgument arg;
     guint i;
@@ -335,7 +335,7 @@ seed_array_from_zero_terminated_c_array(JSContextRef ctx,
         return ret;
     }
 
-    ret = JSObjectMakeArray(ctx, NULL, NULL, NULL);
+    ret = JSObjectMakeArray(ctx, 0, NULL, NULL);
 
 #define ITERATE(type)                                                          \
     do {                                                                       \
@@ -344,7 +344,7 @@ seed_array_from_zero_terminated_c_array(JSContextRef ctx,
             arg.v_##type = array[i];                                           \
             JSValueRef val                                                     \
               = seed_value_from_gi_argument(ctx, &arg, param_info, exception); \
-            seed_object_set_property_at_index(ctx, ret, i, val, exception);    \
+            seed_object_set_property_at_index(ctx, (JSObjectRef) ret, i, val, exception);    \
         }                                                                      \
     } while (0);
 
diff --git a/libseed/seed-types.h b/libseed/seed-types.h
index fe90ae0..5bfc401 100644
--- a/libseed/seed-types.h
+++ b/libseed/seed-types.h
@@ -49,6 +49,17 @@ gboolean seed_object_set_property(JSContextRef ctx,
                                   const gchar* name,
                                   JSValueRef value);
 
+void seed_object_set_property_at_index(JSContextRef ctx,
+                                       JSObjectRef object,
+                                       gint index,
+                                       JSValueRef value,
+                                       JSValueRef* exception);
+
+JSValueRef seed_object_get_property_at_index(JSContextRef ctx,
+                                             JSObjectRef object,
+                                             gint index,
+                                             JSValueRef* exception);
+
 gboolean seed_value_to_gi_argument(JSContextRef ctx,
                                    JSValueRef value,
                                    GITypeInfo* type_info,