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]
> show =
> EOF
$ hg init repo0
$ cd repo0
Command works on an empty repo
$ hg show work
Single draft changeset shown
$ echo 0 > foo
$ hg -q commit -A -m 'commit 0'
$ hg show work
@ 9f17 commit 0
Even when it isn't the wdir
$ hg -q up null
$ hg show work
o 9f17 commit 0
Single changeset is still there when public because it is a head
$ hg phase --public -r 0
$ hg show work
o 9f17 commit 0
A draft child will show both it and public parent
$ hg -q up 0
$ echo 1 > foo
$ hg commit -m 'commit 1'
$ hg show work
@ 181c commit 1
o 9f17 commit 0
Multiple draft children will be shown
$ echo 2 > foo
$ hg commit -m 'commit 2'
$ hg show work
@ 128c commit 2
o 181c commit 1
o 9f17 commit 0
Bumping first draft changeset to public will hide its parent
$ hg phase --public -r 1
$ hg show work
@ 128c commit 2
o 181c commit 1
~
Multiple DAG heads will be shown
$ hg -q up -r 1
$ echo 3 > foo
$ hg commit -m 'commit 3'
created new head
$ hg show work
@ f0ab commit 3
| o 128c commit 2
|/
o 181c commit 1
~
Even when wdir is something else
$ hg -q up null
$ hg show work
o f0ab commit 3
| o 128c commit 2
|/
o 181c commit 1
~
Draft child shows public head (multiple heads)
$ hg -q up 0
$ echo 4 > foo
$ hg commit -m 'commit 4'
created new head
$ hg show work
@ 668c commit 4
| o f0ab commit 3
| | o 128c commit 2
| |/
| o 181c commit 1
|/
o 9f17 commit 0
$ cd ..
Branch name appears in output
$ hg init branches
$ cd branches
$ echo 0 > foo
$ hg -q commit -A -m 'commit 0'
$ echo 1 > foo
$ hg commit -m 'commit 1'
$ echo 2 > foo
$ hg commit -m 'commit 2'
$ hg phase --public -r .
$ hg -q up -r 1
$ hg branch mybranch
marked working directory as branch mybranch
(branches are permanent and global, did you want a bookmark?)
$ echo 3 > foo
$ hg commit -m 'commit 3'
$ echo 4 > foo
$ hg commit -m 'commit 4'
$ hg show work
@ f8dd (mybranch) commit 4
o 90cf (mybranch) commit 3
| o 128c commit 2
|/
o 181c commit 1
~
$ cd ..
Bookmark name appears in output
$ hg init bookmarks
$ cd bookmarks
$ echo 0 > foo
$ hg -q commit -A -m 'commit 0'
$ echo 1 > foo
$ hg commit -m 'commit 1'
$ echo 2 > foo
$ hg commit -m 'commit 2'
$ hg phase --public -r .
$ hg bookmark @
$ hg -q up -r 1
$ echo 3 > foo
$ hg commit -m 'commit 3'
created new head
$ echo 4 > foo
$ hg commit -m 'commit 4'
$ hg bookmark mybook
$ hg show work
@ cac8 (mybook) commit 4
o f0ab commit 3
| o 128c (@) commit 2
|/
o 181c commit 1
~
$ cd ..
Tags are rendered
$ hg init tags
$ cd tags
$ echo 0 > foo
$ hg -q commit -A -m 'commit 1'
$ echo 1 > foo
$ hg commit -m 'commit 2'
$ hg tag 0.1
$ hg phase --public -r .
$ echo 2 > foo
$ hg commit -m 'commit 3'
$ hg tag 0.2
$ hg show work
@ 3758 Added tag 0.2 for changeset 6379c25b76f1
o 6379 (0.2) commit 3
o a2ad Added tag 0.1 for changeset 6a75536ea0b1
~
$ cd ..
Multiple names on same changeset render properly
$ hg init multiplenames
$ cd multiplenames
$ echo 0 > foo
$ hg -q commit -A -m 'commit 1'
$ hg phase --public -r .
$ hg branch mybranch
marked working directory as branch mybranch
(branches are permanent and global, did you want a bookmark?)
$ hg bookmark mybook
$ echo 1 > foo
$ hg commit -m 'commit 2'
$ hg show work
@ 3483 (mybook) (mybranch) commit 2
o 97fc commit 1
Multiple bookmarks on same changeset render properly
$ hg book mybook2
$ hg show work
@ 3483 (mybook mybook2) (mybranch) commit 2
o 97fc commit 1
$ cd ..
Extra namespaces are rendered
$ hg init extranamespaces
$ cd extranamespaces
$ echo 0 > foo
$ hg -q commit -A -m 'commit 1'
$ hg phase --public -r .
$ echo 1 > foo
$ hg commit -m 'commit 2'
$ echo 2 > foo
$ hg commit -m 'commit 3'
$ hg --config extensions.revnames=$TESTDIR/revnamesext.py show work
@ 32f3 (r2) commit 3
o 6a75 (r1) commit 2
o 97fc (r0) commit 1
Obsolescence information appears in labels.
$ cat >> .hg/hgrc << EOF
> [experimental]
> evolution=createmarkers
> EOF
$ hg debugobsolete `hg log -r 'desc("commit 2")' -T "{node}"`
1 new obsolescence markers
obsoleted 1 changesets
1 new orphan changesets
$ hg show work --color=debug
@ [log.changeset changeset.draft changeset.unstable instability.orphan|32f3] [log.description|commit 3]
x [log.changeset changeset.draft changeset.obsolete|6a75] [log.description|commit 2]
~
$ cd ..
Prefix collision on hashes increases shortest node length
$ hg init hashcollision
$ cd hashcollision
$ echo 0 > a
$ hg -q commit -Am 0
$ for i in 17 1057 2857 4025; do
> hg -q up 0
> echo $i > a
> hg -q commit -m $i
> echo 0 > a
> hg commit -m "$i commit 2"
> done
$ hg show work
@ cfd04 4025 commit 2
o c562d 4025
| o 08048 2857 commit 2
| o c5623 2857
|/
| o 6a6b6 1057 commit 2
| o c5625 1057
|/
| o 96b4e 17 commit 2
| o 11424 17
|/
o b4e73 0
$ cd ..