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 no-reposimplestore
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [narrow]
> serveellipses=True
> EOF
$ for x in `$TESTDIR/seq.py 10`
> do
> echo $x > "f$x"
> hg add "f$x"
> done
$ hg commit -m "Add root files"
$ mkdir d1 d2
$ for x in `$TESTDIR/seq.py 10`
> do
> echo d1/$x > "d1/f$x"
> hg add "d1/f$x"
> echo d2/$x > "d2/f$x"
> hg add "d2/f$x"
> done
$ hg commit -m "Add d1 and d2"
$ for x in `$TESTDIR/seq.py 10`
> do
> echo f$x rev2 > "f$x"
> echo d1/f$x rev2 > "d1/f$x"
> echo d2/f$x rev2 > "d2/f$x"
> hg commit -m "Commit rev2 of f$x, d1/f$x, d2/f$x"
> done
$ cd ..
narrow and shallow clone the d2 directory
$ hg clone --narrow ssh://user@dummy/master shallow --include "d2" --depth 2
requesting all changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 13 changes to 10 files
new changesets *:* (glob)
updating to branch default
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd shallow
$ hg log -T '{rev}{if(ellipsis,"...")}: {desc}\n'
3: Commit rev2 of f10, d1/f10, d2/f10
2: Commit rev2 of f9, d1/f9, d2/f9
1: Commit rev2 of f8, d1/f8, d2/f8
0...: Commit rev2 of f7, d1/f7, d2/f7
$ hg update 0
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat d2/f7 d2/f8
d2/f7 rev2
d2/8
$ cd ..
change every upstream file once
$ cd master
$ for x in `$TESTDIR/seq.py 10`
> do
> echo f$x rev3 > "f$x"
> echo d1/f$x rev3 > "d1/f$x"
> echo d2/f$x rev3 > "d2/f$x"
> hg commit -m "Commit rev3 of f$x, d1/f$x, d2/f$x"
> done
$ cd ..
pull new changes with --depth specified. There were 10 changes to the d2
directory but the shallow pull should only fetch 3.
$ cd shallow
$ hg pull --depth 2
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 10 changes to 10 files
new changesets *:* (glob)
(run 'hg update' to get a working copy)
$ hg log -T '{rev}{if(ellipsis,"...")}: {desc}\n'
7: Commit rev3 of f10, d1/f10, d2/f10
6: Commit rev3 of f9, d1/f9, d2/f9
5: Commit rev3 of f8, d1/f8, d2/f8
4...: Commit rev3 of f7, d1/f7, d2/f7
3: Commit rev2 of f10, d1/f10, d2/f10
2: Commit rev2 of f9, d1/f9, d2/f9
1: Commit rev2 of f8, d1/f8, d2/f8
0...: Commit rev2 of f7, d1/f7, d2/f7
$ hg update 4
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat d2/f7 d2/f8
d2/f7 rev3
d2/f8 rev2
$ hg update 7
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat d2/f10
d2/f10 rev3
$ cd ..
cannot clone with zero or negative depth
$ hg clone --narrow ssh://user@dummy/master bad --include "d2" --depth 0
requesting all changes
remote: abort: depth must be positive, got 0
abort: pull failed on remote
[100]
$ hg clone --narrow ssh://user@dummy/master bad --include "d2" --depth -1
requesting all changes
remote: abort: depth must be positive, got -1
abort: pull failed on remote
[100]