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

@@ -257,8 +257,12 @@ 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)
 {	
+	if (chan)
 		ast_autoservice_start(chan);
+
 	ast_copy_string(buf, get_lock(chan, data, 0) ? "0" : "1", len);
+
+	if (chan)
 		ast_autoservice_stop(chan);
 
 	return 0;
@@ -266,8 +270,12 @@ static int lock_read(struct ast_channel *chan, const char *cmd, char *data, char
 
 static int trylock_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
 {
+	if (chan)
 		ast_autoservice_start(chan);
+
 	ast_copy_string(buf, get_lock(chan, data, 1) ? "0" : "1", len);
+
+	if (chan)
 		ast_autoservice_stop(chan);
 
 	return 0;

funcs/func_shell.c

@@ -49,6 +49,7 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
 		return -1;
 	}
 
+	if (chan)
 		ast_autoservice_start(chan);
 
 	if (len >= 1) {
@@ -62,6 +63,7 @@ static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
 		pclose(ptr);
 	}
 
+	if (chan)
 		ast_autoservice_stop(chan);
 
 	return 0;