some fixes

source/src/docs.cpp

@@ -409,6 +409,7 @@ void renderdoc(int x, int y, int doch)
     if(!docvisible) return;
 
     char *exp = getcurcommand();
+    if(!exp || !*exp) return;
 
     int o = 0; //offset
     int f = 0; //last found