Make sure a channel exists before attempting to start or stop channel

autoservice in func_lock and func_shell.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@87233 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_lock.c

@@ -256,19 +256,27 @@ static int unlock_read(struct ast_channel *chan, const char *cmd, char *data, ch
 }
 
 static int lock_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
-{
-	ast_autoservice_start(chan);
+{	
+	if (chan)
+		ast_autoservice_start(chan);
+
 	ast_copy_string(buf, get_lock(chan, data, 0) ? "0" : "1", len);
-	ast_autoservice_stop(chan);
+
+	if (chan)
+		ast_autoservice_stop(chan);
 
 	return 0;
 }
 
 static int trylock_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
 {
-	ast_autoservice_start(chan);
+	if (chan)
+		ast_autoservice_start(chan);
+
 	ast_copy_string(buf, get_lock(chan, data, 1) ? "0" : "1", len);
-	ast_autoservice_stop(chan);
+
+	if (chan)
+		ast_autoservice_stop(chan);
 
 	return 0;
 }

funcs/func_shell.c

@@ -49,7 +49,8 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
 		return -1;
 	}
 
-	ast_autoservice_start(chan);
+	if (chan)
+		ast_autoservice_start(chan);
 
 	if (len >= 1) {
 		FILE *ptr;
@@ -62,7 +63,8 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
 		pclose(ptr);
 	}
 
-	ast_autoservice_stop(chan);
+	if (chan)
+		ast_autoservice_stop(chan);
 
 	return 0;
 }