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.
Test the "--base" flag of the rebase command. (Tests unrelated to the "--base"
flag should probably live in somewhere else)
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> drawdag=$TESTDIR/drawdag.py
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} {desc}"
> EOF
$ rebasewithdag() {
> N=`"$PYTHON" -c "print($N+1)"`
> hg init repo$N && cd repo$N
> hg debugdrawdag
> hg rebase "$@" > _rebasetmp
> r=$?
> grep -v 'saved backup bundle' _rebasetmp
> [ $r -eq 0 ] && hg tglog
> cd ..
> return $r
> }
Single branching point, without merge:
$ rebasewithdag -b D -d Z <<'EOS'
> D E
> |/
> Z B C # C: branching point, E should be picked
> \|/ # B should not be picked
> A
> |
> R
> EOS
rebasing 3:d6003a550c2c C "C"
rebasing 5:4526cf523425 D "D"
rebasing 6:b296604d9846 E tip "E"
o 6: 4870f5e7df37 E
|
| o 5: dc999528138a D
|/
o 4: 6b3e11729672 C
|
o 3: 57e70bad1ea3 Z
|
| o 2: c1e6b162678d B
|/
o 1: 21a6c4502885 A
|
o 0: b41ce7760717 R
Multiple branching points caused by selecting a single merge changeset:
$ rebasewithdag -b E -d Z <<'EOS'
> E
> /|
> B C D # B, C: multiple branching points
> | |/ # D should not be picked
> Z | /
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d B "B"
rebasing 3:d6003a550c2c C "C"
rebasing 6:54c8f00cb91c E tip "E"
o 6: 00598421b616 E
|\
| o 5: 6b3e11729672 C
| |
o | 4: 85260910e847 B
|/
o 3: 57e70bad1ea3 Z
|
| o 2: 8924700906fe D
|/
o 1: 21a6c4502885 A
|
o 0: b41ce7760717 R
Rebase should not extend the "--base" revset using "descendants":
$ rebasewithdag -b B -d Z <<'EOS'
> E
> /|
> Z B C # descendants(B) = B+E. With E, C will be included incorrectly
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d B "B"
rebasing 5:54c8f00cb91c E tip "E"
o 5: e583bf3ff54c E
|\
| o 4: 85260910e847 B
| |
| o 3: 57e70bad1ea3 Z
| |
o | 2: d6003a550c2c C
|/
o 1: 21a6c4502885 A
|
o 0: b41ce7760717 R
Rebase should not simplify the "--base" revset using "roots":
$ rebasewithdag -b B+E -d Z <<'EOS'
> E
> /|
> Z B C # roots(B+E) = B. Without E, C will be missed incorrectly
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d B "B"
rebasing 3:d6003a550c2c C "C"
rebasing 5:54c8f00cb91c E tip "E"
o 5: 00598421b616 E
|\
| o 4: 6b3e11729672 C
| |
o | 3: 85260910e847 B
|/
o 2: 57e70bad1ea3 Z
|
o 1: 21a6c4502885 A
|
o 0: b41ce7760717 R
The destination is one of the two branching points of a merge:
$ rebasewithdag -b F -d Z <<'EOS'
> F
> / \
> E D
> / /
> Z C
> \ /
> B
> |
> A
> EOS
nothing to rebase
[1]
Multiple branching points caused by multiple bases (issue5420):
$ rebasewithdag -b E1+E2+C2+B1 -d Z <<'EOS'
> Z E2
> | /
> F E1 C2
> |/ /
> E C1 B2
> |/ /
> C B1
> |/
> B
> |
> A
> |
> R
> EOS
rebasing 3:a113dbaa660a B1 "B1"
rebasing 5:06ce7b1cc8c2 B2 "B2"
rebasing 6:0ac98cce32d3 C1 "C1"
rebasing 8:781512f5e33d C2 "C2"
rebasing 9:428d8c18f641 E1 "E1"
rebasing 11:e1bf82f6b6df E2 "E2"
o 12: e4a37b6fdbd2 E2
|
o 11: 9675bea983df E1
|
| o 10: 4faf5d4c80dc C2
| |
| o 9: d4799b1ad57d C1
|/
| o 8: 772732dc64d6 B2
| |
| o 7: ad3ac528a49f B1
|/
o 6: 2cbdfca6b9d5 Z
|
o 5: fcdb3293ec13 F
|
o 4: a4652bb8ac54 E
|
o 3: bd5548558fcf C
|
o 2: c1e6b162678d B
|
o 1: 21a6c4502885 A
|
o 0: b41ce7760717 R
Multiple branching points with multiple merges:
$ rebasewithdag -b G+P -d Z <<'EOS'
> G H P
> |\ /| |\
> F E D M N
> \|/| /| |\
> Z C B I J K L
> \|/ |/ |/
> A A A
> EOS
rebasing 2:dc0947a82db8 C "C"
rebasing 8:4e4f9194f9f1 D "D"
rebasing 9:03ca77807e91 E "E"
rebasing 10:afc707c82df0 F "F"
rebasing 13:690dfff91e9e G "G"
rebasing 14:2893b886bb10 H "H"
rebasing 3:08ebfeb61bac I "I"
rebasing 4:a0a5005cec67 J "J"
rebasing 5:83780307a7e8 K "K"
rebasing 6:e131637a1cb6 L "L"
rebasing 11:d1f6d0c3c7e4 M "M"
rebasing 12:7aaec6f81888 N "N"
rebasing 15:325bc8f1760d P tip "P"
o 15: 6ef6a0ea3b18 P
|\
| o 14: 20ba3610a7e5 N
| |\
o \ \ 13: cd4f6c06d2ab M
|\ \ \
| | | o 12: bca872041455 L
| | | |
| | o | 11: 7bbb6c8a6ad7 K
| | |/
| o / 10: de0cbffe893e J
| |/
o / 9: 0e710f176a88 I
|/
| o 8: 52507bab39ca H
| |\
| | | o 7: bb5fe4652f0d G
| | |/|
| | | o 6: f4ad4b31daf4 F
| | | |
| | o | 5: b168f85f2e78 E
| | |/
| o | 4: 8d09fcdb5594 D
| |\|
+---o 3: ab70b4c5a9c9 C
| |
o | 2: 262e37e34f63 Z
| |
| o 1: 112478962961 B
|/
o 0: 426bada5c675 A
Slightly more complex merge case (mentioned in https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-November/091074.html):
$ rebasewithdag -b A3+B3 -d Z <<'EOF'
> Z C1 A3 B3
> | / / \ / \
> M3 C0 A1 A2 B1 B2
> | / | | | |
> M2 M1 C1 C1 M3
> |
> M1
> |
> M0
> EOF
rebasing 4:8817fae53c94 C0 "C0"
rebasing 6:06ca5dfe3b5b B2 "B2"
rebasing 7:73508237b032 C1 "C1"
rebasing 9:fdb955e2faed A2 "A2"
rebasing 11:4e449bd1a643 A3 "A3"
rebasing 10:0a33b0519128 B1 "B1"
rebasing 12:209327807c3a B3 tip "B3"
o 12: ceb984566332 B3
|\
| o 11: 19d93caac497 B1
| |
| | o 10: 058e73d3916b A3
| | |\
| +---o 9: 0ba13ad72234 A2
| | |
| o | 8: c122c2af10c6 C1
| | |
o | | 7: 74275896650e B2
| | |
| o | 6: 455ba9bd3ea2 C0
|/ /
o | 5: b3d7d2fda53b Z
| |
o | 4: 182ab6383dd7 M3
| |
o | 3: 6c3f73563d5f M2
| |
| o 2: 88c860fffcc2 A1
|/
o 1: bc852baa85dd M1
|
o 0: dbdfc5c9bcd5 M0
Disconnected graph:
$ rebasewithdag -b B -d Z <<'EOS'
> B
> |
> Z A
> EOS
nothing to rebase from 112478962961 to 48b9aae0607f
[1]
Multiple roots. Roots are ancestors of dest:
$ rebasewithdag -b B+D -d Z <<'EOF'
> D Z B
> \|\|
> C A
> EOF
rebasing 2:112478962961 B "B"
rebasing 3:b70f76719894 D "D"
o 4: 511efad7bf13 D
|
| o 3: 25c4e279af62 B
|/
o 2: 3a49f54d7bb1 Z
|\
| o 1: 96cc3511f894 C
|
o 0: 426bada5c675 A
Multiple roots. One root is not an ancestor of dest:
$ rebasewithdag -b B+D -d Z <<'EOF'
> Z B D
> \|\|
> A C
> EOF
nothing to rebase from f675d5a1c6a4+b70f76719894 to 262e37e34f63
[1]
Multiple roots. One root is not an ancestor of dest. Select using a merge:
$ rebasewithdag -b E -d Z <<'EOF'
> E
> |\
> Z B D
> \|\|
> A C
> EOF
rebasing 2:f675d5a1c6a4 B "B"
rebasing 5:f68696fe6af8 E tip "E"
o 5: f6e6f5081554 E
|\
| o 4: 30cabcba27be B
| |\
| | o 3: 262e37e34f63 Z
| | |
o | | 2: b70f76719894 D
|/ /
o / 1: 96cc3511f894 C
/
o 0: 426bada5c675 A
Multiple roots. Two children share two parents while dest has only one parent:
$ rebasewithdag -b B+D -d Z <<'EOF'
> Z B D
> \|\|\
> A C A
> EOF
rebasing 2:f675d5a1c6a4 B "B"
rebasing 3:c2a779e13b56 D "D"
o 4: 5eecd056b5f8 D
|\
+---o 3: 30cabcba27be B
| |/
| o 2: 262e37e34f63 Z
| |
o | 1: 96cc3511f894 C
/
o 0: 426bada5c675 A