Eingabedaten pruefen

Change-Id: Ifce8ff1798879d801c4fb9934344e454476ad67a
diff --git a/p/daemon/debug.c b/p/daemon/debug.c
index 3a92cb3..15ea947 100644
--- a/p/daemon/debug.c
+++ b/p/daemon/debug.c
@@ -18,6 +18,9 @@
     
     if ( ch != "debug" && ch != "entwicklung" && ch != "warnungen" )
         return 0;
+
+    if (!stringp(txt) || !sizeof(txt))
+        return 0;
     
     ch = capitalize(ch);