bug: seek() to negative position doesn't set $! to EINVAL

[toddr-bot]

Problem

In Test::MockFile::FileHandle, when seek() attempts to seek to a negative position, it returns 0 (failure) but does NOT set $! to EINVAL.

# FileHandle.pm, SEEK method
if ( $new_pos < 0 ) {
    return 0;  # Missing: $! = EINVAL
}

Expected behavior

Real Perl's seek() sets $! to EINVAL when the resulting position would be negative.

Reproduction

use Test::MockFile;
use Errno qw(EINVAL);

my $file = Test::MockFile->file('/mock/test', 'hello');
open my $fh, '<', '/mock/test' or die;
my $result = seek($fh, -10, 0);  # Seek to negative position
# $result is 0 (correct), but $! is not EINVAL (bug)

Severity

🟢 Low — incorrect error reporting, but the operation itself correctly fails.

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🤖 Created by Kōan from audit session