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.
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ mkdir dir
$ mkdir dir/src
$ cd dir/src
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "f$x"; hg add "f$x"; hg commit -m "Commit src $x"; done
$ cd ..
$ mkdir tests
$ cd tests
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "t$x"; hg add "t$x"; hg commit -m "Commit test $x"; done
$ cd ../../..
narrow clone a file, f10
$ hg clone --narrow ssh://user@dummy/master narrow --noupdate --include "dir/src/f10"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 1 changes to 1 files
new changesets *:* (glob)
$ cd narrow
$ hg debugrequires | grep -v generaldelta
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
narrowhg-experimental
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
testonly-simplestore (reposimplestore !)
$ hg tracked
I path:dir/src/f10
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/src
dir/src/f10
$ cat dir/src/f10
10
$ cd ..
narrow clone a directory, tests/, except tests/t19
$ hg clone --narrow ssh://user@dummy/master narrowdir --noupdate --include "dir/tests/" --exclude "dir/tests/t19"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 19 changes to 19 files
new changesets *:* (glob)
$ cd narrowdir
$ hg tracked
I path:dir/tests
X path:dir/tests/t19
$ hg update
19 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/tests
dir/tests/t1
dir/tests/t10
dir/tests/t11
dir/tests/t12
dir/tests/t13
dir/tests/t14
dir/tests/t15
dir/tests/t16
dir/tests/t17
dir/tests/t18
dir/tests/t2
dir/tests/t20
dir/tests/t3
dir/tests/t4
dir/tests/t5
dir/tests/t6
dir/tests/t7
dir/tests/t8
dir/tests/t9
$ cd ..
narrow clone everything but a directory (tests/)
$ hg clone --narrow ssh://user@dummy/master narrowroot --noupdate --exclude "dir/tests"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 20 changes to 20 files
new changesets *:* (glob)
$ cd narrowroot
$ hg tracked
I path:.
X path:dir/tests
$ hg update
20 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/src
dir/src/f1
dir/src/f10
dir/src/f11
dir/src/f12
dir/src/f13
dir/src/f14
dir/src/f15
dir/src/f16
dir/src/f17
dir/src/f18
dir/src/f19
dir/src/f2
dir/src/f20
dir/src/f3
dir/src/f4
dir/src/f5
dir/src/f6
dir/src/f7
dir/src/f8
dir/src/f9
$ cd ..
Testing the --narrowspec flag to clone
$ cat >> narrowspecs <<EOF
> %include foo
> [include]
> path:dir/tests/
> path:dir/src/f12
> EOF
$ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
reading narrowspec from '$TESTTMP/narrowspecs'
config error: cannot specify other files using '%include' in narrowspec
[30]
$ cat > narrowspecs <<EOF
> [include]
> path:dir/tests/
> path:dir/src/f12
> EOF
$ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
reading narrowspec from '$TESTTMP/narrowspecs'
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 21 changes to 21 files
new changesets 681085829a73:26ce255d5b5d
updating to branch default
21 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd specfile
$ hg tracked
I path:dir/src/f12
I path:dir/tests
$ cd ..