[grilo] core: handle NULL as NOP for grl_data_*_for_id()

[Victor Toso <victortoso src gnome org>]

commit 2be94f85ccc39039bbe391b5795582c148d757bd
Author: Victor Toso <me victortoso com>
Date:   Mon Sep 3 12:38:49 2018 +0200

    core: handle NULL as NOP for grl_data_*_for_id()
    
    To avoid handling a value that is treated as NOP by
    grl_data_set () anyway.
    
    Signed-off-by: Victor Toso <victortoso gnome org>

 src/data/grl-data.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/src/data/grl-data.c b/src/data/grl-data.c
index 8720349..e9317ae 100644
--- a/src/data/grl-data.c
+++ b/src/data/grl-data.c
@@ -658,6 +658,9 @@ grl_data_set_for_id (GrlData *data, const gchar *key_name, const GValue *value)
   GrlRegistry *registry;
   GrlKeyID key_id;
 
+  if (value == NULL)
+    return TRUE;
+
   key_name = g_intern_string (key_name);
   g_return_val_if_fail (is_canonical (key_name), FALSE);
 
@@ -703,6 +706,9 @@ grl_data_add_for_id (GrlData *data, const gchar *key_name, const GValue *value)
   GrlRegistry *registry;
   GrlKeyID key_id;
 
+  if (value == NULL)
+    return TRUE;
+
   key_name = g_intern_string (key_name);
   g_return_val_if_fail (is_canonical (key_name), FALSE);