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.
$ hg init test
$ cd test
$ echo 0 >> afile
$ hg add afile
$ hg commit -m "0.0"
$ echo 1 >> afile
$ hg commit -m "0.1"
$ echo 2 >> afile
$ hg commit -m "0.2"
$ echo 3 >> afile
$ hg commit -m "0.3"
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo 1 >> afile
$ hg commit -m "1.1"
created new head
$ echo 2 >> afile
$ hg commit -m "1.2"
$ echo a line > fred
$ echo 3 >> afile
$ hg add fred
$ hg commit -m "1.3"
$ hg mv afile adifferentfile
$ hg commit -m "1.3m"
$ hg update -C 3
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg mv afile anotherfile
$ hg commit -m "0.3m"
$ hg debugrevlogindex -f 1 afile
rev flag size link p1 p2 nodeid
0 0000 2 0 -1 -1 362fef284ce2
1 0000 4 1 0 -1 125144f7e028
2 0000 6 2 1 -1 4c982badb186
3 0000 8 3 2 -1 19b1fc555737
$ hg debugindex adifferentfile
rev linkrev nodeid p1-nodeid p2-nodeid
0 7 2565f3199a74 000000000000 000000000000
$ hg debugindex anotherfile
rev linkrev nodeid p1-nodeid p2-nodeid
0 8 2565f3199a74 000000000000 000000000000
$ hg debugindex fred
rev linkrev nodeid p1-nodeid p2-nodeid
0 6 12ab3bcc5ea4 000000000000 000000000000
$ hg debugindex --manifest
rev linkrev nodeid p1-nodeid p2-nodeid
0 0 43eadb1d2d06 000000000000 000000000000
1 1 8b89697eba2c 43eadb1d2d06 000000000000
2 2 626a32663c2f 8b89697eba2c 000000000000
3 3 f54c32f13478 626a32663c2f 000000000000
4 6 de68e904d169 626a32663c2f 000000000000
5 7 09bb521d218d de68e904d169 000000000000
6 8 1fde233dfb0f f54c32f13478 000000000000
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 9 changesets with 7 changes to 4 files
$ cd ..
$ for i in 0 1 2 3 4 5 6 7 8; do
> echo
> echo ---- hg clone -r "$i" test test-"$i"
> hg clone -r "$i" test test-"$i"
> cd test-"$i"
> hg verify
> cd ..
> done
---- hg clone -r 0 test test-0
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets f9ee2f85a263
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
---- hg clone -r 1 test test-1
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets f9ee2f85a263:34c2bf6b0626
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
---- hg clone -r 2 test test-2
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets f9ee2f85a263:e38ba6f5b7e0
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 1 files
---- hg clone -r 3 test test-3
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
new changesets f9ee2f85a263:eebf5a27f8ca
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 4 changesets with 4 changes to 1 files
---- hg clone -r 4 test test-4
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets f9ee2f85a263:095197eb4973
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
---- hg clone -r 5 test test-5
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets f9ee2f85a263:1bb50a9436a7
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 1 files
---- hg clone -r 6 test test-6
adding changesets
adding manifests
adding file changes
added 4 changesets with 5 changes to 2 files
new changesets f9ee2f85a263:7373c1169842
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 4 changesets with 5 changes to 2 files
---- hg clone -r 7 test test-7
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 3 files
new changesets f9ee2f85a263:a6a34bfa0076
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 5 changesets with 6 changes to 3 files
---- hg clone -r 8 test test-8
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files
new changesets f9ee2f85a263:aa35859c02ea
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 5 changesets with 5 changes to 2 files
$ cd test-8
$ hg pull ../test-7
pulling from ../test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 2 changes to 3 files (+1 heads)
new changesets 095197eb4973:a6a34bfa0076
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 9 changesets with 7 changes to 4 files
$ cd ..
$ hg clone test test-9
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd test-9
$ hg branch foobar
marked working directory as branch foobar
(branches are permanent and global, did you want a bookmark?)
$ echo file2 >> file2
$ hg add file2
$ hg commit -m "changeset9"
$ echo file3 >> file3
$ hg add file3
$ hg commit -m "changeset10"
$ cd ..
$ hg clone -r 9 -u foobar test-9 test-10
adding changesets
adding manifests
adding file changes
added 6 changesets with 6 changes to 3 files
new changesets f9ee2f85a263:7100abb79635
updating to branch foobar
2 files updated, 0 files merged, 0 files removed, 0 files unresolved