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.
#testcases continuecommand continueflag
#if continueflag
$ cat >> $HGRCPATH <<EOF
> [alias]
> continue = rebase --continue
> EOF
#endif
$ . "$TESTDIR/narrow-library.sh"
create full repo
$ hg init master
$ cd master
$ mkdir inside
$ echo inside1 > inside/f1
$ echo inside2 > inside/f2
$ mkdir outside
$ echo outside1 > outside/f1
$ echo outside2 > outside/f2
$ hg ci -Aqm 'initial'
$ echo modified > inside/f1
$ hg ci -qm 'modify inside/f1'
$ hg update -q 0
$ echo modified2 > inside/f2
$ hg ci -qm 'modify inside/f2'
$ hg update -q 0
$ echo modified > outside/f1
$ hg ci -qm 'modify outside/f1'
$ hg update -q 0
$ echo modified2 > outside/f1
$ hg ci -qm 'conflicting outside/f1'
$ cd ..
$ hg clone --narrow ssh://user@dummy/master narrow --include inside
requesting all changes
adding changesets
adding manifests
adding file changes
added 5 changesets with 4 changes to 2 files (+3 heads)
new changesets *:* (glob)
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> EOF
$ hg update -q 0
Can rebase onto commit where no files outside narrow spec are involved
$ hg update -q 0
$ echo modified > inside/f2
$ hg ci -qm 'modify inside/f2'
$ hg rebase -d 'desc("modify inside/f1")'
rebasing 5:c2f36d04e05d tip "modify inside/f2"
saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)
Can rebase onto conflicting changes inside narrow spec
$ hg update -q 0
$ echo conflicting > inside/f1
$ hg ci -qm 'conflicting inside/f1'
$ hg rebase -d 'desc("modify inside/f1")' 2>&1 | egrep -v '(warning:|incomplete!)'
rebasing 6:cdce97fbf653 tip "conflicting inside/f1"
merging inside/f1
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
$ echo modified3 > inside/f1
$ hg resolve -m 2>&1 | grep -v continue:
(no more unresolved files)
$ hg continue
rebasing 6:cdce97fbf653 tip "conflicting inside/f1"
saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)
Can rebase onto non-conflicting changes outside narrow spec
$ hg update -q 0
$ echo modified > inside/f2
$ hg ci -qm 'modify inside/f2'
$ hg rebase -d 'desc("modify outside/f1")'
rebasing 7:c2f36d04e05d tip "modify inside/f2"
saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)
Rebase interrupts on conflicting changes outside narrow spec
$ hg update -q 'desc("conflicting outside/f1")'
$ hg phase -f -d .
$ hg rebase -d 'desc("modify outside/f1")'
rebasing 4:707c035aadb6 "conflicting outside/f1"
abort: conflict in file 'outside/f1' is outside narrow clone
[20]