Modifications to the playqueue-clear command:

- do not stop playback when clearing the UpNext queue
- clear history, if mode=0x68697374 ("hist")

src/httpd_dacp.c

@@ -1219,51 +1219,50 @@ dacp_reply_playqueuecontents(struct evhttp_request *req, struct evbuffer *evbuf,
 	DPRINTF(E_LOG, L_DACP, "Invalid span value in playqueue-contents request\n");
     }
 
-  songlist = NULL;
   i = 0;
   n = 0; // count of songs in songlist
-  player_get_status(&status);
-
-  /* Get queue and make songlist only if playing or paused */
-  if (status.status != PLAY_STOPPED)
+  songlist = evbuffer_new();
+  if (!songlist)
     {
-      songlist = evbuffer_new();
-      if (!songlist)
-        {
-          DPRINTF(E_LOG, L_DACP, "Could not allocate songlist evbuffer for playqueue-contents\n");
+      DPRINTF(E_LOG, L_DACP, "Could not allocate songlist evbuffer for playqueue-contents\n");
 
-          dmap_send_error(req, "ceQR", "Out of memory");
-          return;
-        }
+      dmap_send_error(req, "ceQR", "Out of memory");
+      return;
+    }
 
-      /*
-       * If the span parameter is negativ make song list for Previously Played,
-       * otherwise make song list for Up Next and begin with first song after playlist position.
-       */
-      if (span < 0)
+  /*
+   * If the span parameter is negativ make song list for Previously Played,
+   * otherwise make song list for Up Next and begin with first song after playlist position.
+   */
+  if (span < 0)
+    {
+      history = player_history_get();
+      if (abs(span) > history->count)
 	{
-	  history = player_history_get();
-	  if (abs(span) > history->count)
-	    {
-	      start_index = history->start_index;
-	    }
-	  else
-	    {
-	      start_index = (history->start_index + history->count - abs(span)) % MAX_HISTORY_COUNT;
-	    }
-	  for (n = 0; n < history->count && n < abs(span); n++)
-	    {
-	      ret = playqueuecontents_add_source(songlist, history->id[(start_index + n) % MAX_HISTORY_COUNT], (n + 1), status.plid);
-	      if (ret < 0)
-		{
-		  DPRINTF(E_LOG, L_DACP, "Could not add song to songlist for playqueue-contents\n");
-
-		  dmap_send_error(req, "ceQR", "Out of memory");
-		  return;
-		}
-	    }
+	  start_index = history->start_index;
 	}
       else
+	{
+	  start_index = (history->start_index + history->count - abs(span)) % MAX_HISTORY_COUNT;
+	}
+      for (n = 0; n < history->count && n < abs(span); n++)
+	{
+	  ret = playqueuecontents_add_source(songlist, history->id[(start_index + n) % MAX_HISTORY_COUNT], (n + 1), status.plid);
+	  if (ret < 0)
+	    {
+	      DPRINTF(E_LOG, L_DACP, "Could not add song to songlist for playqueue-contents\n");
+
+	      dmap_send_error(req, "ceQR", "Out of memory");
+	      return;
+	    }
+	}
+    }
+  else
+    {
+      player_get_status(&status);
+
+      /* Get queue and make songlist only if playing or paused */
+      if (status.status != PLAY_STOPPED)
 	{
 	  /* Fast forward to song currently being played */
 	  head = player_queue_get();
@@ -1271,7 +1270,7 @@ dacp_reply_playqueuecontents(struct evhttp_request *req, struct evbuffer *evbuf,
 	    {
 	      ps = head;
 	      while ((ps->id != status.id) && (ps = next_ps(ps, status.shuffle)) && (ps != head))
-	        i++;
+		i++;
 
 	      while ((n < abs(span)) && (ps = next_ps(ps, status.shuffle)) && (ps != head))
 		{
@@ -1365,6 +1364,32 @@ dacp_reply_playqueuecontents(struct evhttp_request *req, struct evbuffer *evbuf,
   httpd_send_reply(req, HTTP_OK, "OK", evbuf);
 }
 
+static void
+dacp_reply_playqueueedit_clear(struct evhttp_request *req, struct evbuffer *evbuf, char **uri, struct evkeyvalq *query)
+{
+  const char *param;
+  int clear_hist;
+
+  clear_hist = 0;
+  param = evhttp_find_header(query, "mode");
+
+  /*
+   * The mode parameter contains the playlist to be cleared.
+   * If mode=0x68697374 (hex representation of the ascii string "hist") clear the history,
+   * otherwise the current playlist.
+   */
+  if (strcmp(param,"0x68697374") == 0)
+    clear_hist = 1;
+
+  player_queue_empty(clear_hist);
+
+  dmap_add_container(evbuf, "cacr", 24); /* 8 + len */
+  dmap_add_int(evbuf, "mstt", 200);      /* 12 */
+  dmap_add_int(evbuf, "miid", 0);        /* 12 */
+
+  httpd_send_reply(req, HTTP_OK, "OK", evbuf);
+}
+
 static void
 dacp_reply_playqueueedit_add(struct evhttp_request *req, struct evbuffer *evbuf, char **uri, struct evkeyvalq *query)
 {
@@ -1630,7 +1655,7 @@ dacp_reply_playqueueedit(struct evhttp_request *req, struct evbuffer *evbuf, cha
     }
 
   if (strcmp(param, "clear") == 0)
-    dacp_reply_cue_clear(req, evbuf, uri, query);
+    dacp_reply_playqueueedit_clear(req, evbuf, uri, query);
   else if (strcmp(param, "playnow") == 0)
     dacp_reply_cue_play(req, evbuf, uri, query);
   else if (strcmp(param, "add") == 0)

src/player.c

@@ -3588,6 +3588,50 @@ queue_clear(struct player_command *cmd)
   return 0;
 }
 
+static int
+queue_empty(struct player_command *cmd)
+{
+  int clear_hist;
+  struct player_source *ps;
+
+  clear_hist = cmd->arg.intval;
+  if (clear_hist)
+    {
+      memset(history, 0, sizeof(struct player_history));
+    }
+  else
+    {
+      if (!source_head || !cur_streaming)
+	return 0;
+
+      // Stop playback if playing and streaming song are not the same
+      if (!cur_playing || cur_playing != cur_streaming)
+	{
+	  playback_stop(cmd);
+	  queue_clear(cmd);
+	  return 0;
+	}
+
+      // Set head to the current playing song
+      shuffle_head = cur_playing;
+      source_head = cur_playing;
+
+      // Free all items in the queue except the current playing song
+      for (ps = source_head->pl_next; ps != source_head; ps = ps->pl_next)
+	{
+	  source_free(ps);
+	}
+
+      // Make the queue circular again
+      source_head->pl_next = source_head;
+      source_head->pl_prev = source_head;
+      source_head->shuffle_next = source_head;
+      source_head->shuffle_prev = source_head;
+    }
+
+  return 0;
+}
+
 static int
 queue_plid(struct player_command *cmd)
 {
@@ -4111,6 +4155,22 @@ player_queue_clear(void)
   command_deinit(&cmd);
 }
 
+void
+player_queue_empty(int clear_hist)
+{
+  struct player_command cmd;
+
+  command_init(&cmd);
+
+  cmd.func = queue_empty;
+  cmd.func_bh = NULL;
+  cmd.arg.intval = clear_hist;
+
+  sync_command(&cmd);
+
+  command_deinit(&cmd);
+}
+
 void
 player_queue_plid(uint32_t plid)
 {

src/player.h

@@ -173,6 +173,9 @@ player_queue_remove(int ps_pos_remove);
 void
 player_queue_clear(void);
 
+void
+player_queue_empty(int clear_hist);
+
 void
 player_queue_plid(uint32_t plid);