superfluous code in gunzip.c?

[Robert P. J. Day]

  gunzip.c contains the snippets:

#define GUNZIP_OPT_STDOUT   1
#define GUNZIP_OPT_FORCE    2
#define GUNZIP_OPT_TEST     4
#define GUNZIP_OPT_DECOMPRESS   8    <--- ??

and

opt = bb_getopt_ulflags(argc, argv, "cftd");   <--  "d" ??

but i don't see where that "d" option is being processed and it's not
documented online.  dead code?

rday