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.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
make a test repository that looks like this:
o 2:28bc7b1afd6a
|
| @ 1:d7fe2034f71b
|/
o 0/62ecad8b70e5
$ hg init r0
$ cd r0
$ touch f0
$ hg ci -m0 -Aq
$ touch f1
$ hg ci -m1 -Aq
$ hg update 0 -q
$ touch f2
$ hg ci -m2 -Aq
$ hg update 1 -q
make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1
$ echo cp0 >> fp0
$ hg add fp0
$ hg ci -m p0 -d "0 0"
$ hg export -r. > p0
$ hg strip -qn .
$ hg qimport p0
adding p0 to series file
$ hg qpush
applying p0
now at: p0
$ echo cp1 >> fp1
$ hg add fp1
$ hg qnew p1 -d "0 0"
$ hg qpop -aq
patch queue now empty
qpush --exact when at the parent
$ hg update 1 -q
$ hg qpush -e
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg qpush -e p0
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg qpush -e p1
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact when at another rev
$ hg update 0 -q
$ hg qpush -e
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -e p0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -e p1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -ea
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact while crossing branches
$ hg update 2 -q
$ hg qpush -e
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -e p0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -e p1
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -ea
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact --force with changes to an unpatched file
$ hg update 1 -q
$ echo c0 >> f0
$ hg qpush -e
abort: local changes found
[255]
$ hg qpush -ef
applying p0
now at: p0
$ cat f0
c0
$ rm f0
$ touch f0
$ hg qpop -aq
patch queue now empty
$ hg update 1 -q
$ echo c0 >> f0
$ hg qpush -e p1
abort: local changes found
[255]
$ hg qpush -e p1 -f
applying p0
applying p1
now at: p1
$ cat f0
c0
$ rm f0
$ touch f0
$ hg qpop -aq
patch queue now empty
qpush --exact --force with changes to a patched file
$ hg update 1 -q
$ echo cp0-bad >> fp0
$ hg add fp0
$ hg qpush -e
abort: local changes found
[255]
$ hg qpush -ef
applying p0
file fp0 already exists
1 out of 1 hunks FAILED -- saving rejects to file fp0.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh p0
[2]
$ cat fp0
cp0-bad
$ cat fp0.rej
--- fp0
+++ fp0
@@ -0,0 +1,1 @@
+cp0
$ hg qpop -aqf
patch queue now empty
$ rm fp0
$ rm fp0.rej
$ hg update 1 -q
$ echo cp1-bad >> fp1
$ hg add fp1
$ hg qpush -e p1
abort: local changes found
[255]
$ hg qpush -e p1 -f
applying p0
applying p1
file fp1 already exists
1 out of 1 hunks FAILED -- saving rejects to file fp1.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh p1
[2]
$ cat fp1
cp1-bad
$ cat fp1.rej
--- fp1
+++ fp1
@@ -0,0 +1,1 @@
+cp1
$ hg qpop -aqf
patch queue now empty
$ hg forget fp1
$ rm fp1
$ rm fp1.rej
qpush --exact when already at a patch
$ hg update 1
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg qpush -e p0
applying p0
now at: p0
$ hg qpush -e p1
abort: cannot push --exact with applied patches
[255]
$ hg qpop -aq
patch queue now empty
qpush --exact --move should fail
$ hg qpush -e --move p1
abort: cannot use --exact and --move together
[255]
qpush --exact a patch without a parent recorded
$ hg qpush -q
now at: p0
$ grep -v '# Parent' .hg/patches/p0 > p0.new
$ mv p0.new .hg/patches/p0
$ hg qpop -aq
patch queue now empty
$ hg qpush -e
abort: p0 does not have a parent recorded
[255]
$ hg qpush -e p0
abort: p0 does not have a parent recorded
[255]
$ hg qpush -e p1
abort: p0 does not have a parent recorded
[255]
$ hg qpush -ea
abort: p0 does not have a parent recorded
[255]
$ cd ..