It doesn't ignore the class name.

Instead, it appears to me by overwriting the namespace of Bar, you're overwriting everything in Bar::, including it's "identity". So class Bar is from now on, identified as class Foo.

Check out this similar, but even more reduced code:

{
    package Foo;
    sub foo { bless {}, "Bar" }
}

*Bar:: = \*Foo::;

use Data::Dumper;
print Dumper(Foo->foo);
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There's no reason why it wouldn't print "Bar" for the class, no? Yet, this is the result I get:

$VAR1 = bless( {}, 'Foo' );
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Drop the assignment of the stash, and it behaves as you and I expect.

I have no idea where the identity of the class is stored in the stash, but it must be somewhere — and you're overwriting it.

update: Replace the assignment of the stash with the less rigorous:

*Bar::foo = \*Foo::foo;
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and it still behaves as expected, yielding:

$VAR1 = bless( {}, 'Bar' );
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whether you call it like either of:

print Dumper(Foo->foo);
print Dumper(Bar->foo);
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