2 updates to mp3 metadata handling. allow a 0 metadata interval to disable

metadata being sent to new listeners (negative for whatever the source
sends), existing listeners retain their original interval setting.  We now
limit how much mp3 is written after the metadata block in a single format
send call, this was only showing up on small interval values.

svn path=/icecast/trunk/icecast/; revision=9877

src/format_mp3.c

@@ -197,7 +197,7 @@ static void format_mp3_apply_settings (client_t *client, format_plugin_t *format
 {
     mp3_state *source_mp3 = format->_state;
 
-    if (mount == NULL || mount->mp3_meta_interval <= 0)
+    if (mount == NULL || mount->mp3_meta_interval < 0)
     {
         char *metadata = httpp_getvar (client->parser, "icy-metaint");
         source_mp3->interval = -1;
@@ -376,6 +376,9 @@ static int format_mp3_write_buf_to_client(client_t *client)
                 /* change buf and len */
                 buf += remaining;
                 len -= remaining;
+                /* limit how much mp3 we send if using small intervals */
+                if (len > client_mp3->interval)
+                    len = client_mp3->interval;
             }
         }
         /* write any mp3, maybe after the metadata block */
@@ -635,16 +638,19 @@ static int format_mp3_create_client_data(source_t *source, client_t *client)
     metadata = httpp_getvar(client->parser, "icy-metadata");
     if (metadata && atoi(metadata))
     {
-        if (source_mp3->interval > 0)
+        if (source_mp3->interval >= 0)
             client_mp3->interval = source_mp3->interval;
         else
             client_mp3->interval = ICY_METADATA_INTERVAL;
-        bytes = snprintf (ptr, remaining, "icy-metaint:%u\r\n",
-                client_mp3->interval);
-        if (bytes > 0)
+        if (client_mp3->interval)
         {
-            remaining -= bytes;
-            ptr += bytes;
+            bytes = snprintf (ptr, remaining, "icy-metaint:%u\r\n",
+                    client_mp3->interval);
+            if (bytes > 0)
+            {
+                remaining -= bytes;
+                ptr += bytes;
+            }
         }
     }
     bytes = snprintf (ptr, remaining, "\r\n");