(argp_doc): Make sure NULL is not passed to dgettext

diff --git a/lib/argp-help.c b/lib/argp-help.c
index 8f5c73adc5fca6beba918ea97c3f316d29b6eafb..e7baaf9ff888c08f4b3e03f7071f093e92c4a323 100644 (file)
--- a/lib/argp-help.c
+++ b/lib/argp-help.c
@@ -1496,7 +1496,7 @@ argp_doc (const struct argp *argp, const struct argp_state *state,
        }
       else
        inp_text = post ? 0 : argp->doc;
-      trans_text = dgettext (argp->argp_domain, inp_text);
+      trans_text = inp_text ? dgettext (argp->argp_domain, inp_text) : NULL;
     }
   else
     trans_text = inp_text = 0;