fix: supporting empty dirs in mp_dirlist. Test updated.

all.sas

@@ -4214,6 +4214,13 @@ data &out_ds(compress=no
   %end;
   if rc = 0 then do;
     did = dopen(fref);
+    if did=0 then do;
+      putlog "NOTE: This directory is empty, or does not exist - &path";
+      msg=sysmsg();
+      put msg;
+      put _all_;
+      stop;
+    end;
     /* attribute is OS-dependent - could be "Directory" or "Directory Name" */
     numopts=doptnum(did);
     do i=1 to numopts;
@@ -4221,12 +4228,6 @@ data &out_ds(compress=no
       if foption=:'Directory' then i=numopts;
     end;
     directory=dinfo(did,foption);
-    if did=0 then do;
-      putlog "NOTE: This directory is empty - " directory;
-      msg=sysmsg();
-      put _all_;
-      stop;
-    end;
     rc = filename(fref);
   end;
   else do;
@@ -4362,7 +4363,8 @@ run;
 proc sql;
 drop table &out_ds;
 
-%mend mp_dirlist;/**
+%mend mp_dirlist;
+/**
   @file
   @brief Creates a dataset containing distinct _formatted_ values
   @details If no format is supplied, then the original value is used instead.