bug: I/O operations on closed mocked filehandle succeed silently

[toddr-bot]

Summary

After close($fh), operations on mocked filehandles silently succeed instead of failing like real Perl. This means tests using Test::MockFile can pass even when the code under test incorrectly operates on closed handles.

Reproduction

use Test::MockFile qw(nostrict);
my $f = Test::MockFile->file("/tmp/test.txt", "hello");
open my $fh, "+<", "/tmp/test.txt" or die;
close $fh;

# All of these should fail, but succeed on mocked handles:
print $fh "test";         # returns 1 (should: undef + warning)
read($fh, my $buf, 10);   # returns 8 (should: undef + warning)
tell($fh);                # returns 12 (should: -1 + warning)
seek($fh, 0, 0);          # returns "0 but true" (should: false + warning)
readline($fh);            # returns data (should: undef + warning)

Expected behavior

Match real Perl: warn "op() on closed filehandle" and return failure values.

Fix

PR #344

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🤖 Created by Kōan from autonomous session