Add sanity checking for position resuming. We *have* to make sure that the position does not exceed the total number of files present, and we have to make sure that the position's filename is the same as previous. These values can change if a music class is reloaded and give unpredictable behavior.

(closes issue #11663)
Reported by: junky


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.4@110035 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 8 insertions, 2 deletions

diff --git a/res/res_musiconhold.c b/res/res_musiconhold.c
index 87b327897..491eacb8b 100644
--- a/res/res_musiconhold.c
+++ b/res/res_musiconhold.c
@@ -120,6 +120,7 @@ struct moh_files_state {
 	int sample_queue;
 	int pos;
 	int save_pos;
+	char *save_pos_filename;
 };
 
 #define MOH_QUIET		(1 << 0)
@@ -239,8 +240,8 @@ static int ast_moh_files_next(struct ast_channel *chan)
 		return -1;
 	}
 
-	/* If a specific file has been saved, use it */
-	if (state->save_pos >= 0) {
+	/* If a specific file has been saved confirm it still exists and that it is still valid */
+	if (state->save_pos >= 0 && state->save_pos < state->class->total_files && state->class->filearray[state->save_pos] == state->save_pos_filename) {
 		state->pos = state->save_pos;
 		state->save_pos = -1;
 	} else if (ast_test_flag(state->class, MOH_RANDOMIZE)) {
@@ -250,11 +251,13 @@ static int ast_moh_files_next(struct ast_channel *chan)
 			if (ast_fileexists(state->class->filearray[state->pos], NULL, NULL) > 0)
 				break;
 		}
+		state->save_pos = -1;
 		state->samples = 0;
 	} else {
 		/* This is easy, just increment our position and make sure we don't exceed the total file count */
 		state->pos++;
 		state->pos %= state->class->total_files;
+		state->save_pos = -1;
 		state->samples = 0;
 	}
 
@@ -265,6 +268,9 @@ static int ast_moh_files_next(struct ast_channel *chan)
 		return -1;
 	}
 
+	/* Record the pointer to the filename for position resuming later */
+	state->save_pos_filename = state->class->filearray[state->pos];
+
 	if (option_debug)
 		ast_log(LOG_DEBUG, "%s Opened file %d '%s'\n", chan->name, state->pos, state->class->filearray[state->pos]);