- various enhancements in drivers

pardef.c

@@ -241,6 +241,7 @@ char *ParArg2Str(int argc, char *argv[], char *result, int maxsize)
     for (i = 0; i < argc; i++) {
       argsize += strlen(argv[i]) + 1;
     }
+    if (argsize == 0) argsize = 1;
     result = malloc(argsize);
     if (!result)
       return NULL;