#!/usr/bin/perl
<DATA>;
$.= 39;
print "$. $_" while <DATA>;
__DATA__

line 1
line 2
line 3
[download]

#!/usr/bin/perl

seek DATA,0,0;
print "$. $_" while <DATA>;
__DATA__

line 1
line 2
line 3
[download]

1 #!/usr/bin/perl
2 
3 seek DATA,0,0;
4 print "$. $_" while <DATA>;
5 __DATA__
6 
7 line 1
8 line 2
9 line 3
[download]

Bug or feature? :-)

cheers,
--shmem

Update: this is covered implicitly in perl561delta, Potential to leak DATA filehandles:

       Using the "__DATA__" token creates an implicit filehandle to th
+e file
       that contains the token.  It is the program's responsibility to
+ close it
       when it is done reading from it.
[download]

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}