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.
Path conflict checking is currently disabled by default because of issue5716.
Turn it on for this test.
$ cat >> $HGRCPATH << EOF
> [experimental]
> merge.checkpathconflicts=True
> EOF
$ hg init repo
$ cd repo
$ echo base > base
$ hg add base
$ hg commit -m "base"
$ hg bookmark -i base
$ echo 1 > a
$ hg add a
$ hg commit -m "file"
$ hg bookmark -i file
$ echo 2 > a
$ hg commit -m "file2"
$ hg bookmark -i file2
$ hg up -q 0
$ mkdir a
$ echo 2 > a/b
$ hg add a/b
$ hg commit -m "dir"
created new head
$ hg bookmark -i dir
Basic merge - local file conflicts with remote directory
$ hg up -q file
$ hg bookmark -i
$ hg merge --verbose dir
resolving manifests
a: path conflict - a file or link has the same name as a directory
the local file has been renamed to a~853701544ac3
resolve manually then use 'hg resolve --mark a'
moving a to a~853701544ac3
getting a/b
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg update --clean .
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ rm a~853701544ac3
Basic update - local directory conflicts with remote file
$ hg up -q 0
$ mkdir a
$ echo 3 > a/b
$ hg up file
a: untracked directory conflicts with file
abort: untracked files in working directory differ from files in requested revision
[20]
$ hg up --clean file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file)
Repo state is ok
$ hg sum
parent: 1:853701544ac3
file
branch: default
bookmarks: *file
commit: (clean)
update: 2 new changesets (update)
phases: 4 draft
Basic update - untracked file conflicts with remote directory
$ hg up -q 0
$ echo untracked > a
$ hg up --config merge.checkunknown=warn dir
a: replacing untracked file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark dir)
$ cat a.orig
untracked
$ rm -f a.orig
Basic clean update - local directory conflicts with changed remote file
$ hg up -q file
$ rm a
$ mkdir a
$ echo 4 > a/b
$ hg up file2
abort: *: *$TESTTMP/repo/a* (glob)
[255]
$ hg up --clean file2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file2)
Repo state is ok
$ hg sum
parent: 2:f64e09fac717
file2
branch: default
bookmarks: *file2
commit: (clean)
update: 1 new changesets, 2 branch heads (merge)
phases: 4 draft