--- main/channel.c-old	2009-11-01 00:17:12.000000000 +0300
+++ main/channel.c	2009-11-01 00:18:42.000000000 +0300
@@ -1326,12 +1326,12 @@
 
 	ast_channel_lock(chan);
 
-	if (cmp_args->name) { /* match by name */
+	if (cmp_args->name && cmp_args->name[0]) { /* match by name */
 		if ((!name_len && strcasecmp(chan->name, cmp_args->name)) ||
 				(name_len && strncasecmp(chan->name, cmp_args->name, name_len))) {
 			ret = 0; /* name match failed */
 		}
-	} else if (cmp_args->exten) {
+	} else if (cmp_args->exten && cmp_args->exten[0]) {
 		if (cmp_args->context && strcasecmp(chan->context, cmp_args->context) &&
 				strcasecmp(chan->macrocontext, cmp_args->context)) {
 			ret = 0; /* context match failed */
@@ -1340,11 +1340,13 @@
 				strcasecmp(chan->macroexten, cmp_args->exten)) {
 			ret = 0; /* exten match failed */
 		}
-	} else if (cmp_args->uniqueid) {
+	} else if (cmp_args->uniqueid && cmp_args->uniqueid[0]) {
 		if ((!name_len && strcasecmp(chan->uniqueid, cmp_args->uniqueid)) ||
 				(name_len && strncasecmp(chan->uniqueid, cmp_args->uniqueid, name_len))) {
 			ret = 0; /* uniqueid match failed */
 		}
+	} else {
+		ret = 0;
 	}
 
 	ast_channel_unlock(chan);