procutil: make stream detection in make_line_buffered more correct and strict In make_line_buffered(), we don’t want to wrap the stream if we know that lines get flushed to the underlying raw stream already. Previously, the heuristic was too optimistic. It assumed that any stream which is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there are buffered streams that aren’t instances of io.BufferedIOBase, like Mercurial’s own winstdout. The new logic is different in two ways: First, only for the check, if unwraps any combination of WriteAllWrapper and winstdout. Second, it skips wrapping the stream only if it is an instance of io.RawIOBase (or already wrapped). If it is an instance of io.BufferedIOBase, it gets wrapped. In any other case, the function raises an exception. This ensures that, if an unknown stream is passed or we add another wrapper in the future, we don’t wrap the stream if it’s already line buffered or not wrap the stream if it’s not line buffered. In fact, this was already helpful during development of this change. Without it, I possibly would have forgot that WriteAllWrapper needs to be ignored for the check, leading to unnecessary wrapping if stdout is unbuffered. The alternative would have been to always wrap unknown streams. However, I don’t think that anyone would benefit from being less strict. We can expect streams from the standard library to be subclassing either io.RawIOBase or io.BufferedIOBase, so running Mercurial in the standard way should not regress by this change. Py2exe might replace sys.stdout and sys.stderr, but that currently breaks Mercurial anyway and also these streams don’t claim to be interactive, so this function is not called for them.

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Mercurial for Plan 9 from Bell Labs

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===================================

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This directory contains support for Mercurial on Plan 9 from Bell Labs

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platforms. It is assumed that the version of Python running on these

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systems supports the ANSI/POSIX Environment (APE). At the time of this

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writing, the bichued/python port is the most commonly installed version

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of Python on these platforms. If a native port of Python is ever made,

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some minor modification will need to be made to support some of the more

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esoteric requirements of the platform rather than those currently made

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(cf. posix.py).

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By default, installations will have the factotum extension enabled; this

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extension permits factotum(4) to act as an authentication agent for

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HTTP repositories. Additionally, an extdiff command named 9diff is

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enabled which generates diff(1) compatible output suitable for use with

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the plumber(4).

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Commit messages are plumbed using E if no editor is defined; users must

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update the plumbed file to continue, otherwise the hg process must be

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interrupted.

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Some work remains with regard to documentation. Section 5 manual page

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references for hgignore and hgrc need to be re-numbered to section 6 (file

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formats) and a new man page writer should be written to support the

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Plan 9 man macro set. Until these issues can be resolved, manual pages

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are elided from the installation.

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Basic install:

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  % mk install      # do a system-wide install

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  % hg debuginstall # sanity-check setup

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  % hg              # see help

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A proto(2) file is included in this directory as an example of how a

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binary distribution could be packaged, ostensibly with contrib(1).

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See https://mercurial-scm.org/ for detailed installation

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instructions, platform-specific notes, and Mercurial user information.