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.
this structure seems to tickle a bug in bundle's search for
changesets, so first we have to recreate it
o 8
|
| o 7
| |
| o 6
|/|
o | 5
| |
o | 4
| |
| o 3
| |
| o 2
|/
o 1
|
o 0
$ mkrev()
> {
> revno=$1
> echo "rev $revno"
> echo "rev $revno" > foo.txt
> hg -q ci -m"rev $revno"
> }
setup test repo1
$ hg init repo1
$ cd repo1
$ echo "rev 0" > foo.txt
$ hg ci -Am"rev 0"
adding foo.txt
$ mkrev 1
rev 1
first branch
$ mkrev 2
rev 2
$ mkrev 3
rev 3
back to rev 1 to create second branch
$ hg up -r1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkrev 4
rev 4
$ mkrev 5
rev 5
merge first branch to second branch
$ hg up -C -r5
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ HGMERGE=internal:local hg merge
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo "merge rev 5, rev 3" > foo.txt
$ hg ci -m"merge first branch to second branch"
one more commit following the merge
$ mkrev 7
rev 7
back to "second branch" to make another head
$ hg up -r5
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkrev 8
rev 8
the story so far
$ hg log -G --template "{rev}\n"
@ 8
|
| o 7
| |
| o 6
|/|
o | 5
| |
o | 4
| |
| o 3
| |
| o 2
|/
o 1
|
o 0
check that "hg outgoing" really does the right thing
sanity check of outgoing: expect revs 4 5 6 7 8
$ hg clone -r3 . ../repo2
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
new changesets 6ae4cca4e39a:478f191e53f8
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
this should (and does) report 5 outgoing revisions: 4 5 6 7 8
$ hg outgoing --template "{rev}\n" ../repo2
comparing with ../repo2
searching for changes
4
5
6
7
8
test bundle (destination repo): expect 5 revisions
this should bundle the same 5 revisions that outgoing reported, but it
actually bundles 7
$ hg bundle foo.bundle ../repo2
searching for changes
5 changesets found
test bundle (base revision): expect 5 revisions
this should (and does) give exactly the same result as bundle
with a destination repo... i.e. it's wrong too
$ hg bundle --base 3 foo.bundle
5 changesets found
$ cd ..