In the following code:

use strict;
use warnings;

sub foo {return 'foo';}

die "No bar here" if bar () ne 'bar';
print foo () . "\n";
print bar () . "\n";

sub bar {return 'bar';}
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I get the following output:

Unquoted string "bar" may clash with future reserved word at noname.pl
+ line 8.
foo
Use of uninitialized value in concatenation (.) or string at noname.pl
+ line 8.
print() on unopened filehandle bar at noname.pl line 8.
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The text foo is sent to stdout, the remainder is sent to stderr. Note that the die isn't executed.

If I change the print bar to print '' . bar then I get the output I expect without error messages. What is going on here?