no_data.pl has no DATA section at all, but B::Deparse includes the part from the used module.

This example shows that neither \*main::DATA nor \*last_pckg::DATA can be reliably used without further information.

We either need a mechanism to get the real filehandle of the current file (maybe thru B ?) or a way to identify the file associated to those filehandles (for check against $0)

lanx@nc10-ubuntu:/tmp$ cat no_data.pl 
use wrong_data;
print <DATA>;

lanx@nc10-ubuntu:/tmp$ cat wrong_data.pm 
1;

__DATA__
wrong main::DATA  

lanx@nc10-ubuntu:/tmp$ perl -MO=Deparse no_data.pl 
use wrong_data;
print <DATA>;
__DATA__
wrong main::DATA  
no_data.pl syntax OK

lanx@nc10-ubuntu:/tmp$ perl no_data.pl 
wrong_main::DATA
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for completeness: The deparsed code will produce the same results now in this special case!