[Train] Allow contextlib.redirect_stdout() to bypass print redirect to logs

[Mr-Neutr0n]

When Ray Train's print patch is active, any library that uses contextlib.redirect_stdout() to capture print output gets broken — the patched redirected_print sends everything to the logger unconditionally when file is stdout or None, even if stdout has been replaced by a StringIO via redirect_stdout().

This is what happens with smart_open, which builds its docstring by capturing print output at import time. On Ray workers the print patch runs first, so when smart_open gets imported later as a transitive dep, the docstring text ends up in the logger instead of being captured.

The fix checks whether sys.stdout/sys.stderr have been redirected (i.e. they're not sys.__stdout__/sys.__stderr__) and falls back to the original print in that case. This way redirect_stdout() works as expected while normal prints still get routed through the logger.

Also fixed a minor bug on the custom-file fallback path where _original_print(objects, ...) was missing the * unpack (should be _original_print(*objects, ...)).

Fixes #61050

[gemini-code-assist]

Code Review

This pull request correctly fixes an issue where the patched print function in Ray Train would interfere with contextlib.redirect_stdout(). The fix involves checking if sys.stdout or sys.stderr have been redirected and, if so, falling back to the original print function. A new test case has been added to verify this behavior. Additionally, a minor bug related to argument unpacking in the call to the original print function is also fixed. The changes are logical and well-implemented. I've added one suggestion to make the code slightly more concise.

[github-actions]

This pull request has been automatically marked as stale because it has not had
any activity for 14 days. It will be closed in another 14 days if no further activity occurs.
Thank you for your contributions.

You can always ask for help on our discussion forum or Ray's public slack channel.

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[github-actions]

This pull request has been automatically closed because there has been no more activity in the 14 days
since being marked stale.

Please feel free to reopen or open a new pull request if you'd still like this to be addressed.

Again, you can always ask for help on our discussion forum or Ray's public slack channel.

Thanks again for your contribution!

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Reviewed by Cursor Bugbot for commit a10bcb2. Configure here.}

[pseudo-rnd-thoughts]

Thanks for the PR, overall looks good. Could you just merge the two if statements and add to the test