codec: webvtt: split the code to acutally Delete webvtt_dom_node_t data

So we don't use recursions. We only need an extra loop on the child elements
to delete. But it will not cause a recursion.

modules/codec/webvtt/subsvtt.c

@@ -461,41 +461,50 @@ static void webvtt_domnode_AppendLast( webvtt_dom_node_t **pp_append,
 #define webvtt_domnode_AppendLast( a, b ) \
     webvtt_domnode_AppendLast( (webvtt_dom_node_t **) a, (webvtt_dom_node_t *) b )
 
+
+static webvtt_dom_node_t *webvtt_domnode_DeleteNode( webvtt_dom_node_t *p_node )
+{
+    webvtt_dom_node_t *p_child = NULL;
+    if( p_node->type == NODE_TAG )
+    {
+        webvtt_dom_tag_t *p_tag_node = (webvtt_dom_tag_t *) p_node;
+        text_style_Delete( p_tag_node->p_cssstyle );
+        free( p_tag_node->psz_attrs );
+        free( p_tag_node->psz_tag );
+        p_child = p_tag_node->p_child;
+    }
+    else if( p_node->type == NODE_TEXT )
+    {
+        webvtt_dom_text_t *p_text_node = (webvtt_dom_text_t *)p_node;
+        free( p_text_node->psz_text );
+    }
+    else if( p_node->type == NODE_CUE )
+    {
+        webvtt_dom_cue_t *p_cue_node = (webvtt_dom_cue_t *)p_node;
+        text_style_Delete( p_cue_node->p_cssstyle );
+        webvtt_cue_settings_Clean( &p_cue_node->settings );
+        free( p_cue_node->psz_id );
+        p_child = p_cue_node->p_child;
+    }
+    else if( p_node->type == NODE_REGION )
+    {
+        webvtt_region_t *p_region_node = (webvtt_region_t *)p_node;
+        text_style_Delete( p_region_node->p_cssstyle );
+        free( p_region_node->psz_id );
+        p_child = p_region_node->p_child;
+    }
+    free( p_node );
+    return p_child;
+}
+
 static void webvtt_domnode_ChainDelete( webvtt_dom_node_t *p_node )
 {
     while( p_node )
     {
         webvtt_dom_node_t *p_next = p_node->p_next;
-
-        if( p_node->type == NODE_TAG )
-        {
-            webvtt_dom_tag_t *p_tag_node = (webvtt_dom_tag_t *) p_node;
-            text_style_Delete( p_tag_node->p_cssstyle );
-            free( p_tag_node->psz_attrs );
-            free( p_tag_node->psz_tag );
-            webvtt_domnode_ChainDelete( p_tag_node->p_child );
-        }
-        else if( p_node->type == NODE_TEXT )
-        {
-            webvtt_dom_text_t *p_text_node = (webvtt_dom_text_t *)p_node;
-            free( p_text_node->psz_text );
-        }
-        else if( p_node->type == NODE_CUE )
-        {
-            webvtt_dom_cue_t *p_cue_node = (webvtt_dom_cue_t *)p_node;
-            text_style_Delete( p_cue_node->p_cssstyle );
-            webvtt_cue_settings_Clean( &p_cue_node->settings );
-            free( p_cue_node->psz_id );
-            webvtt_domnode_ChainDelete( p_cue_node->p_child );
-        }
-        else if( p_node->type == NODE_REGION )
-        {
-            webvtt_region_t *p_region_node = (webvtt_region_t *)p_node;
-            text_style_Delete( p_region_node->p_cssstyle );
-            free( p_region_node->psz_id );
-            webvtt_domnode_ChainDelete( p_region_node->p_child );
-        }
-        free( p_node );
+        webvtt_dom_node_t *p_child = webvtt_domnode_DeleteNode( p_node );
+        while ( p_child )
+            p_child = webvtt_domnode_DeleteNode( p_child );
 
         p_node = p_next;
     }