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.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepos ()
> {
> hg init r
> cd r
> for x in a b c ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg clone r r2 | grep -v updating
> cd r2
> for x in d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg init r3
> cd r3
> for x in g h i ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> }
$ initrepos
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
show the edit commands offered by outgoing
$ cd r2
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between 055a42cdd887 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
abort: repository is unrelated
[1]
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --force --outgoing ../r
comparing with ../r
searching for changes
warning: repository is unrelated
pick 2a4042b45417 0 g
pick 68c46b4927ce 1 h
pick 51281e65ba79 2 i
# Edit history between 2a4042b45417 and 51281e65ba79
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
test sensitivity to branch in URL:
$ cd r2
$ hg -q update 2
$ hg -q branch foo
$ hg commit -m 'create foo branch'
$ HGEDITOR=cat hg histedit --outgoing '../r#foo' | grep -v comparing | grep -v searching
pick f26599ee3441 6 create foo branch
# Edit history between f26599ee3441 and f26599ee3441
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
test to check number of roots in outgoing revisions
$ hg -q outgoing -G --template '{node|short}({branch})' '../r'
@ f26599ee3441(foo)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[20]
$ hg -q update -C 2
$ echo aa >> a
$ hg -q commit -m 'another head on default'
$ hg -q outgoing -G --template '{node|short}({branch})' '../r#default'
@ 3879dc049647(default)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r#default'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[20]
$ cd ..