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 'hgext.mq =' >> $HGRCPATH
$ hg init repo
$ cd repo
$ echo foo > foo
$ hg ci -qAm 'add a file'
$ hg qinit
$ hg qnew foo
$ echo foo >> foo
$ hg qrefresh -m 'append foo'
$ hg qnew bar
$ echo bar >> foo
$ hg qrefresh -m 'append bar'
Try to operate on public mq changeset
$ hg qpop
popping bar
now at: foo
$ hg phase --public qbase
$ echo babar >> foo
$ hg qref
abort: cannot qrefresh public revision
(see 'hg help phases' for details)
[255]
$ hg revert -a
reverting foo
$ hg qpop
abort: popping would remove a public revision
(see 'hg help phases' for details)
[255]
$ hg qfold bar
abort: cannot qrefresh public revision
(see 'hg help phases' for details)
[255]
$ hg revert -a
reverting foo
restore state for remaining test
$ hg qpush
applying bar
now at: bar
try to commit on top of a patch
$ echo quux >> foo
$ hg ci -m 'append quux'
abort: cannot commit over an applied mq patch
[255]
cheat a bit...
$ mv .hg/patches .hg/patches2
$ hg ci -m 'append quux'
$ mv .hg/patches2 .hg/patches
qpop/qrefresh on the wrong revision
$ hg qpop
abort: popping would remove a revision not managed by this patch queue
[255]
$ hg qpop -n patches
using patch queue: $TESTTMP/repo/.hg/patches
abort: popping would remove a revision not managed by this patch queue
[255]
$ hg qrefresh
abort: working directory revision is not qtip
[255]
$ hg up -C qtip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg qpop
abort: popping would remove a revision not managed by this patch queue
[255]
$ hg qrefresh
abort: cannot qrefresh a revision with children
[255]
$ hg tip --template '{rev} {desc}\n'
3 append quux
qpush warning branchheads
$ cd ..
$ hg init branchy
$ cd branchy
$ echo q > q
$ hg add q
$ hg qnew -f qp
$ hg qpop
popping qp
patch queue now empty
$ echo a > a
$ hg ci -Ama
adding a
$ hg up null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ echo c > c
$ hg ci -Amc
adding c
$ hg merge default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -mmerge
$ hg up default
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg log
changeset: 2:65309210bf4e
branch: b
tag: tip
parent: 1:707adb4c8ae1
parent: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge
changeset: 1:707adb4c8ae1
branch: b
parent: -1:000000000000
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: c
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ hg qpush
applying qp
now at: qp
Testing applied patches, push and --force
$ cd ..
$ hg init forcepush
$ cd forcepush
$ echo a > a
$ hg ci -Am adda
adding a
$ echo a >> a
$ hg ci -m changea
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch branch
marked working directory as branch branch
(branches are permanent and global, did you want a bookmark?)
$ echo b > b
$ hg ci -Am addb
adding b
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg --cwd .. clone -r 0 forcepush forcepush2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 07f494440405
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo a >> a
$ hg qnew patch
Pushing applied patch with --rev without --force
$ hg push -r . ../forcepush2
pushing to ../forcepush2
abort: source has mq patches applied
[255]
Pushing applied patch with branchhash, without --force
$ hg push ../forcepush2#default
pushing to ../forcepush2
abort: source has mq patches applied
[255]
Pushing revs excluding applied patch
$ hg push --new-branch -r 'branch(branch)' -r 2 ../forcepush2
pushing to ../forcepush2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
Pushing applied patch with --force
$ hg phase --force --secret 'mq()'
$ hg push --force -r default ../forcepush2
pushing to ../forcepush2
searching for changes
no changes found (ignored 1 secret changesets)
[1]
$ hg phase --draft 'mq()'
$ hg push --force -r default ../forcepush2
pushing to ../forcepush2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
$ cd ..