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.
#require darcs
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert=" >> $HGRCPATH
$ DARCS_EMAIL='test@example.org'; export DARCS_EMAIL
initialize darcs repo
$ mkdir darcs-repo
$ cd darcs-repo
$ darcs init -q
$ echo a > a
$ darcs record -a -l -m p0
Finished recording patch 'p0'
$ cd ..
branch and update
$ darcs get -q darcs-repo darcs-clone >/dev/null
$ cd darcs-clone
$ echo c >> a
$ echo c > c
$ darcs record -a -l -m p1.1
Finished recording patch 'p1.1'
$ cd ..
skip if we can't import elementtree
$ if hg convert darcs-repo darcs-dummy 2>&1 | grep ElementTree > /dev/null; then
> echo 'skipped: missing feature: elementtree module'
> exit 80
> fi
update source
$ cd darcs-repo
$ echo b >> a
$ echo b > b
$ darcs record -a -l -m p1.2
Finished recording patch 'p1.2'
$ darcs pull -q -a --no-set-default ../darcs-clone
Backing up ./a(*) (glob)
We have conflicts in the following files:
./a
(?)
$ sleep 1
$ echo e > a
$ echo f > f
$ mkdir dir
$ echo d > dir/d
$ echo d > dir/d2
$ darcs record -a -l -m p2
Finished recording patch 'p2'
test file and directory move
$ darcs mv -q f ff
Test remove + move
$ darcs remove -q dir/d2
$ rm dir/d2
$ darcs mv -q dir dir2
$ darcs record -a -l -m p3
Finished recording patch 'p3'
The converter does not currently handle patch conflicts very well.
When they occur, it reverts *all* changes and moves forward,
letting the conflict resolving patch fix collisions.
Unfortunately, non-conflicting changes, like the addition of the
"c" file in p1.1 patch are reverted too.
Just to say that manifest not listing "c" here is a bug.
$ cd ..
$ hg convert darcs-repo darcs-repo-hg
initializing destination darcs-repo-hg repository
scanning source...
sorting...
converting...
4 p0
3 p1.2
2 p1.1
1 p2
0 p3
$ hg log -R darcs-repo-hg -g --template '{rev} "{desc|firstline}" ({author}) files: {files}\n' "$@"
4 "p3" (test@example.org) files: dir/d dir/d2 dir2/d f ff
3 "p2" (test@example.org) files: a dir/d dir/d2 f
2 "p1.1" (test@example.org) files:
1 "p1.2" (test@example.org) files: a b
0 "p0" (test@example.org) files: a
$ hg up -q -R darcs-repo-hg
$ hg -R darcs-repo-hg manifest --debug
7225b30cdf38257d5cc7780772c051b6f33e6d6b 644 a
1e88685f5ddec574a34c70af492f95b6debc8741 644 b
37406831adc447ec2385014019599dfec953c806 644 dir2/d
b783a337463792a5c7d548ad85a7d3253c16ba8c 644 ff
#if no-outer-repo
try converting darcs1 repository
$ hg clone -q "$TESTDIR/bundles/darcs1.hg" darcs
$ hg convert -s darcs darcs/darcs1 2>&1 | grep darcs-1.0
darcs-1.0 repository format is unsupported, please upgrade
#endif