httpd_output: disable Icy-Metadata when encoder supports tags

There's no reason to send both encoder tags and Icy-Metadata to the
client.  Let's disable Icy-Metadata when the encoder supports embedded
tags.

src/output/httpd_client.c

@@ -89,6 +89,12 @@ struct httpd_client {
 
 	/* ICY */
 
+	/**
+	 * Do we support sending Icy-Metadata to the client?  This is
+	 * disabled if the httpd audio output uses encoder tags.
+	 */
+	bool metadata_supported;
+
 	/**
 	 * If we should sent icy metadata.
 	 */
@@ -210,7 +216,8 @@ httpd_client_handle_line(struct httpd_client *client, const char *line)
 
 		if (g_ascii_strncasecmp(line, "Icy-MetaData: 1", 15) == 0) {
 			/* Send icy metadata */
-			client->metadata_requested = true;
+			client->metadata_requested =
+				client->metadata_supported;
 			return true;
 		}
 
@@ -417,7 +424,7 @@ httpd_client_in_event(G_GNUC_UNUSED GIOChannel *source, GIOCondition condition,
 }
 
 struct httpd_client *
-httpd_client_new(struct httpd_output *httpd, int fd)
+httpd_client_new(struct httpd_output *httpd, int fd, bool metadata_supported)
 {
 	struct httpd_client *client = g_new(struct httpd_client, 1);
 
@@ -443,6 +450,7 @@ httpd_client_new(struct httpd_output *httpd, int fd)
 	client->input = fifo_buffer_new(4096);
 	client->state = REQUEST;
 
+	client->metadata_supported = metadata_supported;
 	client->metadata_requested = false;
 	client->metadata_sent = true;
 	client->metaint = 8192; /*TODO: just a std value */

src/output/httpd_client.h

@@ -35,7 +35,7 @@ struct page;
  * @param fd the socket file descriptor
  */
 struct httpd_client *
-httpd_client_new(struct httpd_output *httpd, int fd);
+httpd_client_new(struct httpd_output *httpd, int fd, bool metadata_supported);
 
 /**
  * Frees memory and resources allocated by the #httpd_client object.

src/output/httpd_output_plugin.c

@@ -118,7 +118,9 @@ httpd_output_finish(void *data)
 static void
 httpd_client_add(struct httpd_output *httpd, int fd)
 {
-	struct httpd_client *client = httpd_client_new(httpd, fd);
+	struct httpd_client *client =
+		httpd_client_new(httpd, fd,
+				 httpd->encoder->plugin->tag == NULL);
 
 	httpd->clients = g_list_prepend(httpd->clients, client);
 
@@ -380,21 +382,28 @@ httpd_output_tag(void *data, const struct tag *tag)
 
 	assert(tag != NULL);
 
-	if (httpd->metadata != NULL)
+	if (httpd->encoder->plugin->tag != NULL) {
-		page_unref (httpd->metadata);
+		/* embed encoder tags */
 
-	httpd->metadata = icy_server_metadata_page(tag, TAG_ITEM_ALBUM,
+		encoder_tag(httpd->encoder, tag, NULL);
-						   TAG_ITEM_ARTIST,
+	} else {
-						   TAG_ITEM_TITLE,
+		/* use Icy-Metadata */
-						   TAG_NUM_OF_ITEM_TYPES);
 
-	if (httpd->metadata) {
+		if (httpd->metadata != NULL)
-		g_mutex_lock(httpd->mutex);
+			page_unref (httpd->metadata);
-		g_list_foreach(httpd->clients, httpd_send_metadata, httpd->metadata);
+
-		g_mutex_unlock(httpd->mutex);
+		httpd->metadata =
+			icy_server_metadata_page(tag, TAG_ITEM_ALBUM,
+						 TAG_ITEM_ARTIST,
+						 TAG_ITEM_TITLE,
+						 TAG_NUM_OF_ITEM_TYPES);
+		if (httpd->metadata != NULL) {
+			g_mutex_lock(httpd->mutex);
+			g_list_foreach(httpd->clients,
+				       httpd_send_metadata, httpd->metadata);
+			g_mutex_unlock(httpd->mutex);
+		}
 	}
-
-	encoder_tag(httpd->encoder, tag, NULL);
 }
 
 static void