MoH: Don't restart stream on repeated start calls

Currently, music on hold will stop and then start again from the
beginning if ast_moh_start() is called multiple times. This can happen
if a call is put on hold repeatedly (the channel receives multiple
HOLD control frames) and can be triggered from ARI by starting MoH on a
channel multiple times. This is fairly jarring/annoying to users.

This change prevents MoH from being restarted if the requested music
class is the same as the one currently playing.

Review: https://reviewboard.asterisk.org/r/3615/
........

Merged revisions 416150 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@416151 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_musiconhold.c b/res/res_musiconhold.c
index bbc7a162d819b118c29b6071067dd4a9034820c5..c1b3c0e9f7d1b1224fbd14c7573da360029e5867 100644 (file)
--- a/res/res_musiconhold.c
+++ b/res/res_musiconhold.c
@@ -1360,7 +1360,7 @@ static int local_ast_moh_start(struct ast_channel *chan, const char *mclass, con
        struct mohclass *mohclass = NULL;
        struct moh_files_state *state = ast_channel_music_state(chan);
        struct ast_variable *var = NULL;
-       int res;
+       int res = 0;
        int realtime_possible = ast_check_realtime("musiconhold");
 
        /* The following is the order of preference for which class to use:
@@ -1558,10 +1558,12 @@ static int local_ast_moh_start(struct ast_channel *chan, const char *mclass, con
 
        ast_set_flag(ast_channel_flags(chan), AST_FLAG_MOH);
 
-       if (mohclass->total_files) {
-               res = ast_activate_generator(chan, &moh_file_stream, mohclass);
-       } else {
-               res = ast_activate_generator(chan, &mohgen, mohclass);
+       if (!state || strcmp(mohclass->name, state->class->name)) {
+               if (mohclass->total_files) {
+                       res = ast_activate_generator(chan, &moh_file_stream, mohclass);
+               } else {
+                       res = ast_activate_generator(chan, &mohgen, mohclass);
+               }
        }
 
        mohclass = mohclass_unref(mohclass, "unreffing local reference to mohclass in local_ast_moh_start");