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.
#require baz symlink
$ baz my-id "mercurial <mercurial@mercurial-scm.org>"
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert=" >> $HGRCPATH
create baz archive
$ baz make-archive baz@mercurial--convert hg-test-convert-baz
initialize baz repo
$ mkdir baz-repo
$ cd baz-repo/
$ baz init-tree baz@mercurial--convert/baz--test--0
$ baz import
* creating version baz@mercurial--convert/baz--test--0
* imported baz@mercurial--convert/baz--test--0
create initial files
$ echo 'this is a file' > a
$ baz add a
$ mkdir src
$ baz add src
$ cd src
$ dd count=1 if=/dev/zero of=b > /dev/null 2> /dev/null
$ baz add b
HACK: hide GNU tar-1.22 "tar: The --preserve option is deprecated, use --preserve-permissions --preserve-order instead"
$ baz commit -s "added a file, src and src/b (binary)" 2>&1 | grep -v '^tar'
* build pristine tree for baz@mercurial--convert/baz--test--0--base-0
* Scanning for full-tree revision: .
* from import revision: baz@mercurial--convert/baz--test--0--base-0
A/ .arch-ids
A/ src
A/ src/.arch-ids
A .arch-ids/a.id
A a
A src/.arch-ids/=id
A src/.arch-ids/b.id
A src/b
* update pristine tree (baz@mercurial--convert/baz--test--0--base-0 => baz--test--0--patch-1)
* committed baz@mercurial--convert/baz--test--0--patch-1
create link file and modify a
$ ln -s ../a a-link
$ baz add a-link
$ echo 'this a modification to a' >> ../a
$ baz commit -s "added link to a and modify a"
A src/.arch-ids/a-link.id
A src/a-link
M a
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-1 => baz--test--0--patch-2)
* committed baz@mercurial--convert/baz--test--0--patch-2
create second link and modify b
$ ln -s ../a a-link-2
$ baz add a-link-2
$ dd count=1 seek=1 if=/dev/zero of=b > /dev/null 2> /dev/null
$ baz commit -s "added second link and modify b"
A src/.arch-ids/a-link-2.id
A src/a-link-2
Mb src/b
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-2 => baz--test--0--patch-3)
* committed baz@mercurial--convert/baz--test--0--patch-3
b file to link and a-link-2 to regular file
$ rm -f a-link-2
$ echo 'this is now a regular file' > a-link-2
$ ln -sf ../a b
$ baz commit -s "file to link and link to file test"
fl src/b
lf src/a-link-2
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-3 => baz--test--0--patch-4)
* committed baz@mercurial--convert/baz--test--0--patch-4
move a-link-2 file and src directory
$ cd ..
$ baz mv src/a-link-2 c
$ baz mv src test
$ baz commit -s "move and rename a-link-2 file and src directory"
D/ src/.arch-ids
A/ test/.arch-ids
/> src test
=> src/.arch-ids/a-link-2.id .arch-ids/c.id
=> src/a-link-2 c
=> src/.arch-ids/=id test/.arch-ids/=id
=> src/.arch-ids/a-link.id test/.arch-ids/a-link.id
=> src/.arch-ids/b.id test/.arch-ids/b.id
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-4 => baz--test--0--patch-5)
* committed baz@mercurial--convert/baz--test--0--patch-5
move and add the moved file again
$ echo e > e
$ baz add e
$ baz commit -s "add e"
A .arch-ids/e.id
A e
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-5 => baz--test--0--patch-6)
* committed baz@mercurial--convert/baz--test--0--patch-6
$ baz mv e f
$ echo ee > e
$ baz add e
$ baz commit -s "move e and recreate it again"
A .arch-ids/e.id
A e
=> .arch-ids/e.id .arch-ids/f.id
=> e f
* update pristine tree (baz@mercurial--convert/baz--test--0--patch-6 => baz--test--0--patch-7)
* committed baz@mercurial--convert/baz--test--0--patch-7
$ cd ..
converting baz repo to Mercurial
$ hg convert baz-repo baz-repo-hg
initializing destination baz-repo-hg repository
analyzing tree version baz@mercurial--convert/baz--test--0...
scanning source...
sorting...
converting...
7 initial import
6 added a file, src and src/b (binary)
5 added link to a and modify a
4 added second link and modify b
3 file to link and link to file test
2 move and rename a-link-2 file and src directory
1 add e
0 move e and recreate it again
$ baz register-archive -d baz@mercurial--convert
$ glog()
> {
> hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
> }
show graph log
$ glog -R baz-repo-hg
o 7 "move e and recreate it again" files: e f
|
o 6 "add e" files: e
|
o 5 "move and rename a-link-2 file and src directory" files: c src/a-link src/a-link-2 src/b test/a-link test/b
|
o 4 "file to link and link to file test" files: src/a-link-2 src/b
|
o 3 "added second link and modify b" files: src/a-link-2 src/b
|
o 2 "added link to a and modify a" files: a src/a-link
|
o 1 "added a file, src and src/b (binary)" files: a src/b
|
o 0 "initial import" files:
$ hg up -q -R baz-repo-hg
$ hg -R baz-repo-hg manifest --debug
c4072c4b72e1cabace081888efa148ee80ca3cbb 644 a
0201ac32a3a8e86e303dff60366382a54b48a72e 644 c
1a4a864db0073705a11b1439f563bfa4b46d9246 644 e
09e0222742fc3f75777fa9d68a5d8af7294cb5e7 644 f
c0067ba5ff0b7c9a3eb17270839d04614c435623 644 @ test/a-link
375f4263d86feacdea7e3c27100abd1560f2a973 644 @ test/b
$ hg -R baz-repo-hg log -r 5 -r 7 -C --debug | grep copies
copies: c (src/a-link-2) test/a-link (src/a-link) test/b (src/b)
copies: f (e)