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.
$ cat <<EOF >> $HGRCPATH
> [experimental]
> evolution = true
>
> [extensions]
> notify =
> hooklib =
>
> [phases]
> publish = False
>
> [notify]
> sources = pull
> diffstat = False
> messageidseed = example
> domain = example.com
>
> [reposubs]
> * = baz
> EOF
$ hg init a
$ hg --cwd a debugbuilddag +2
$ hg init b
$ cat <<EOF >> b/.hg/hgrc
> [hooks]
> incoming.notify = python:hgext.notify.hook
> txnclose.changeset_obsoleted = python:hgext.hooklib.changeset_obsoleted.hook
> EOF
$ hg --cwd b pull ../a | "$PYTHON" $TESTDIR/unwrap-message-id.py
pulling from ../a
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 0 changes to 0 files
new changesets 1ea73414a91b:66f7d451a68b (2 drafts)
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: * (glob)
Subject: changeset in * (glob)
From: debugbuilddag@example.com
X-Hg-Notification: changeset 1ea73414a91b
Message-Id: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
To: baz@example.com
changeset 1ea73414a91b in $TESTTMP/b
details: $TESTTMP/b?cmd=changeset;node=1ea73414a91b
description:
r0
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: * (glob)
Subject: changeset in * (glob)
From: debugbuilddag@example.com
X-Hg-Notification: changeset 66f7d451a68b
Message-Id: <hg.364d03da7dc13829eb779a805be7e37f54f572e9afcea7d2626856a794d3e8f3@example.com>
To: baz@example.com
changeset 66f7d451a68b in $TESTTMP/b
details: $TESTTMP/b?cmd=changeset;node=66f7d451a68b
description:
r1
(run 'hg update' to get a working copy)
$ hg --cwd a debugobsolete 1ea73414a91b0920940797d8fc6a11e447f8ea1e
1 new obsolescence markers
obsoleted 1 changesets
1 new orphan changesets
$ hg --cwd a push ../b --hidden | "$PYTHON" $TESTDIR/unwrap-message-id.py
1 new orphan changesets
pushing to ../b
searching for changes
no changes found
1 new obsolescence markers
obsoleted 1 changesets
Subject: changeset abandoned
In-reply-to: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
Message-Id: <hg.d6329e9481594f0f3c8a84362b3511318bfbce50748ab1123f909eb6fbcab018@example.com>
Date: * (glob)
From: test@example.com
To: baz@example.com
This changeset has been abandoned.
Check that known changesets with known successors do not result in a mail.
$ hg init c
$ hg init d
$ cat <<EOF >> d/.hg/hgrc
> [hooks]
> incoming.notify = python:hgext.notify.hook
> txnclose.changeset_obsoleted = python:hgext.hooklib.changeset_obsoleted.hook
> EOF
$ hg --cwd c debugbuilddag '.:parent.*parent'
$ hg --cwd c push ../d -r 1
pushing to ../d
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 0 changes to 0 files
$ hg --cwd c debugobsolete $(hg --cwd c log -T '{node}' -r 1) $(hg --cwd c log -T '{node}' -r 2)
1 new obsolescence markers
obsoleted 1 changesets
$ hg --cwd c push ../d | "$PYTHON" $TESTDIR/unwrap-message-id.py
pushing to ../d
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets