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 >> $HGRCPATH<<EOF
> [extensions]
> rebase=
> drawdag=$TESTDIR/drawdag.py
> EOF
$ hg init non-merge
$ cd non-merge
$ hg debugdrawdag<<'EOS'
> F
> |
> E
> |
> D
> |
> B C
> |/
> A
> EOS
$ for i in C D E F; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> E
> |
> D
> |
> B
> EOS
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 E
|
o 6 D
|
| o 5 F BOOK-F
| |
| o 4 E BOOK-E
| |
| o 3 D BOOK-D
| |
| o 2 C BOOK-C
| |
o | 1 B
|/
o 0 A
With --keep, bookmark should move
$ hg rebase -r 3+4 -d E --keep
rebasing 3:e7b3f00ed42e BOOK-D "D"
note: not rebasing 3:e7b3f00ed42e BOOK-D "D", its destination already has all its changes
rebasing 4:69a34c08022a BOOK-E "E"
note: not rebasing 4:69a34c08022a BOOK-E "E", its destination already has all its changes
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 E BOOK-D BOOK-E
|
o 6 D
|
| o 5 F BOOK-F
| |
| o 4 E
| |
| o 3 D
| |
| o 2 C BOOK-C
| |
o | 1 B
|/
o 0 A
Move D and E back for the next test
$ hg bookmark BOOK-D -fqir 3
$ hg bookmark BOOK-E -fqir 4
Bookmark is usually an indication of a head. For changes that are introduced by
an ancestor of bookmark B, after moving B to B-NEW, the changes are ideally
still introduced by an ancestor of changeset on B-NEW. In the below case,
"BOOK-D", and "BOOK-E" include changes introduced by "C".
$ hg rebase -s 2 -d E
rebasing 2:dc0947a82db8 BOOK-C C "C"
rebasing 3:e7b3f00ed42e BOOK-D "D"
note: not rebasing 3:e7b3f00ed42e BOOK-D "D", its destination already has all its changes
rebasing 4:69a34c08022a BOOK-E "E"
note: not rebasing 4:69a34c08022a BOOK-E "E", its destination already has all its changes
rebasing 5:6b2aeab91270 BOOK-F F "F"
saved backup bundle to $TESTTMP/non-merge/.hg/strip-backup/dc0947a82db8-52bb4973-rebase.hg
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 5 F BOOK-F
|
o 4 C BOOK-C BOOK-D BOOK-E
|
o 3 E
|
o 2 D
|
o 1 B
|
o 0 A
Merge and its ancestors all become empty
$ hg init $TESTTMP/merge1
$ cd $TESTTMP/merge1
$ hg debugdrawdag<<'EOS'
> E
> /|
> B C D
> \|/
> A
> EOS
$ for i in C D E; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> H
> |
> D
> |
> C
> |
> B
> EOS
Previously, there was a bug where the empty commit check compared the parent
branch name with the wdir branch name instead of the actual branch name (which
should stay unchanged if --keepbranches is passed), and erroneously assumed
that an otherwise empty changeset should be created because of the incorrectly
assumed branch name change.
$ hg update H -q
$ hg branch foo -q
$ hg rebase -r '(A::)-(B::)-A' -d H --keepbranches
rebasing 2:dc0947a82db8 BOOK-C "C"
note: not rebasing 2:dc0947a82db8 BOOK-C "C", its destination already has all its changes
rebasing 3:b18e25de2cf5 BOOK-D "D"
note: not rebasing 3:b18e25de2cf5 BOOK-D "D", its destination already has all its changes
rebasing 4:86a1f6686812 BOOK-E E "E"
note: not rebasing 4:86a1f6686812 BOOK-E E "E", its destination already has all its changes
saved backup bundle to $TESTTMP/merge1/.hg/strip-backup/b18e25de2cf5-1fd0a4ba-rebase.hg
$ hg update null -q
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 4 H BOOK-C BOOK-D BOOK-E
|
o 3 D
|
o 2 C
|
o 1 B
|
o 0 A
Part of ancestors of a merge become empty
$ hg init $TESTTMP/merge2
$ cd $TESTTMP/merge2
$ hg debugdrawdag<<'EOS'
> G
> /|
> E F
> | |
> B C D
> \|/
> A
> EOS
$ for i in C D E F G; do
> hg bookmark -r $i -i BOOK-$i
> done
$ hg debugdrawdag<<'EOS'
> H
> |
> F
> |
> C
> |
> B
> EOS
$ hg rebase -r '(A::)-(B::)-A' -d H
rebasing 2:dc0947a82db8 BOOK-C "C"
note: not rebasing 2:dc0947a82db8 BOOK-C "C", its destination already has all its changes
rebasing 3:b18e25de2cf5 BOOK-D D "D"
rebasing 4:03ca77807e91 BOOK-E E "E"
rebasing 5:ad6717a6a58e BOOK-F "F"
note: not rebasing 5:ad6717a6a58e BOOK-F "F", its destination already has all its changes
rebasing 6:c58e8bdac1f4 BOOK-G G "G"
saved backup bundle to $TESTTMP/merge2/.hg/strip-backup/b18e25de2cf5-2d487005-rebase.hg
$ hg log -G -T '{rev} {desc} {bookmarks}'
o 7 G BOOK-G
|\
| o 6 E BOOK-E
| |
o | 5 D BOOK-D BOOK-F
|/
o 4 H BOOK-C
|
o 3 F
|
o 2 C
|
o 1 B
|
o 0 A