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.
Create @ bookmark as main reference
$ hg init repo
$ cd repo
$ echo "[extensions]" >> $HGRCPATH
$ echo "patchbomb=" >> $HGRCPATH
$ hg book @
Create a dummy revision that must never be exported
$ echo no > no
$ hg ci -Amno -d '6 0'
adding no
Create a feature and use -B
$ hg book booktest
$ echo first > a
$ hg ci -Amfirst -d '7 0'
adding a
$ echo second > b
$ hg ci -Amsecond -d '8 0'
adding b
$ hg email --date '1981-1-1 0:1' -n -t foo -s bookmark -B booktest
From [test]: test
this patch series consists of 2 patches.
Write the introductory message for the patch series.
Cc:
displaying [PATCH 0 of 2] bookmark ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 0 of 2] bookmark
Message-Id: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:00 +0000
From: test
To: foo
displaying [PATCH 1 of 2] first ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 1 of 2] first
X-Mercurial-Node: accde9b8b6dce861c185d0825c1affc09a79cb26
X-Mercurial-Series-Index: 1
X-Mercurial-Series-Total: 2
Message-Id: <accde9b8b6dce861c185.347155261@test-hostname>
X-Mercurial-Series-Id: <accde9b8b6dce861c185.347155261@test-hostname>
In-Reply-To: <patchbomb.347155260@test-hostname>
References: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:01 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 7 0
# Thu Jan 01 00:00:07 1970 +0000
# Node ID accde9b8b6dce861c185d0825c1affc09a79cb26
# Parent 043bd3889e5aaf7d88fe3713cf425f782ad2fb71
first
diff -r 043bd3889e5a -r accde9b8b6dc a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/a Thu Jan 01 00:00:07 1970 +0000
@@ -0,0 +1,1 @@
+first
displaying [PATCH 2 of 2] second ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 2 of 2] second
X-Mercurial-Node: 417defd1559c396ba06a44dce8dc1c2d2d653f3f
X-Mercurial-Series-Index: 2
X-Mercurial-Series-Total: 2
Message-Id: <417defd1559c396ba06a.347155262@test-hostname>
X-Mercurial-Series-Id: <accde9b8b6dce861c185.347155261@test-hostname>
In-Reply-To: <patchbomb.347155260@test-hostname>
References: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:02 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 8 0
# Thu Jan 01 00:00:08 1970 +0000
# Node ID 417defd1559c396ba06a44dce8dc1c2d2d653f3f
# Parent accde9b8b6dce861c185d0825c1affc09a79cb26
second
diff -r accde9b8b6dc -r 417defd1559c b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/b Thu Jan 01 00:00:08 1970 +0000
@@ -0,0 +1,1 @@
+second
Do the same and combine with -o only one must be exported
$ cd ..
$ hg clone repo repo2
updating to bookmark @
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo
$ hg up @
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
(activating bookmark @)
$ hg book outgoing
$ echo 1 > x
$ hg ci -Am1 -d '8 0'
adding x
created new head
$ hg push ../repo2 -B outgoing
pushing to ../repo2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
exporting bookmark outgoing
$ echo 2 > y
$ hg ci -Am2 -d '9 0'
adding y
$ hg email --date '1982-1-1 0:1' -n -t foo -s bookmark -B outgoing -o ../repo2
comparing with ../repo2
From [test]: test
this patch series consists of 1 patches.
Cc:
displaying [PATCH] bookmark ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH] bookmark
X-Mercurial-Node: 8dab2639fd35f1e337ad866c372a5c44f1064e3c
X-Mercurial-Series-Index: 1
X-Mercurial-Series-Total: 1
Message-Id: <8dab2639fd35f1e337ad.378691260@test-hostname>
X-Mercurial-Series-Id: <8dab2639fd35f1e337ad.378691260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Fri, 01 Jan 1982 00:01:00 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 9 0
# Thu Jan 01 00:00:09 1970 +0000
# Node ID 8dab2639fd35f1e337ad866c372a5c44f1064e3c
# Parent 0b24b8316483bf30bfc3e4d4168e922b169dbe66
2
diff -r 0b24b8316483 -r 8dab2639fd35 y
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/y Thu Jan 01 00:00:09 1970 +0000
@@ -0,0 +1,1 @@
+2