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 >> $HGRCPATH<<EOF
> [extensions]
> drawdag=$TESTDIR/drawdag.py
> [experimental]
> evolution=true
> EOF
$ reinit () {
> rm -rf .hg && hg init
> }
$ hg init
Test what said in drawdag.py docstring
$ hg debugdrawdag <<'EOS'
> c d
> |/
> b
> |
> a
> EOS
$ hg log -G -T '{rev} {desc} ({tags})'
o 3 d (d tip)
|
| o 2 c (c)
|/
o 1 b (b)
|
o 0 a (a)
$ hg debugdrawdag <<'EOS'
> foo bar bar foo
> | / | |
> ancestor(c,d) a baz
> EOS
$ hg log -G -T '{desc}'
o foo
|\
+---o bar
| | |
| o | baz
| /
+---o d
| |
+---o c
| |
o | b
|/
o a
$ reinit
$ hg debugdrawdag <<'EOS'
> o foo
> |\
> +---o bar
> | | |
> | o | baz
> | /
> +---o d
> | |
> +---o c
> | |
> o | b
> |/
> o a
> EOS
$ hg log -G -T '{desc}'
o foo
|\
| | o d
| |/
| | o c
| |/
| | o bar
| |/|
| o | b
| |/
o / baz
/
o a
$ reinit
$ hg debugdrawdag <<'EOS'
> o foo
> |\
> | | o d
> | |/
> | | o c
> | |/
> | | o bar
> | |/|
> | o | b
> | |/
> o / baz
> /
> o a
> EOS
$ hg log -G -T '{desc}'
o foo
|\
| | o d
| |/
| | o c
| |/
| | o bar
| |/|
| o | b
| |/
o / baz
/
o a
$ hg manifest -r a
a
$ hg manifest -r b
a
b
$ hg manifest -r bar
a
b
$ hg manifest -r foo
a
b
baz
Edges existed in repo are no-ops
$ reinit
$ hg debugdrawdag <<'EOS'
> B C C
> | | |
> A A B
> EOS
$ hg log -G -T '{desc}'
o C
|\
| o B
|/
o A
$ hg debugdrawdag <<'EOS'
> C D C
> | | |
> B B A
> EOS
$ hg log -G -T '{desc}'
o D
|
| o C
|/|
o | B
|/
o A
Node with more than 2 parents are disallowed
$ hg debugdrawdag <<'EOS'
> A
> /|\
> D B C
> EOS
abort: A: too many parents: C D B
[255]
Cycles are disallowed
$ hg debugdrawdag <<'EOS'
> A
> |
> A
> EOS
abort: the graph has cycles
[255]
$ hg debugdrawdag <<'EOS'
> A
> |
> B
> |
> A
> EOS
abort: the graph has cycles
[255]
Create obsmarkers via comments
$ reinit
$ hg debugdrawdag <<'EOS'
> G
> |
> I D C F # split: B -> E, F, G
> \ \| | # replace: C -> D -> H
> H B E # prune: F, I
> \|/
> A
> EOS
1 new orphan changesets
$ hg log -r 'sort(all(), topo)' -G --hidden -T '{desc} {node}'
* G 711f53bbef0bebd12eb6f0511d5e2e998b984846
|
x F 64a8289d249234b9886244d379f15e6b650b28e3
|
o E 7fb047a69f220c21711122dfd94305a9efb60cba
|
| x D be0ef73c17ade3fc89dc41701eb9fc3a91b58282
| |
| | x C 26805aba1e600a82e93661149f2313866a221a7b
| |/
| x B 112478962961147124edd43549aedd1a335e44bf
|/
| x I 58e6b987bf7045fcd9c54f496396ca1d1fc81047
| |
| o H 575c4b5ec114d64b681d33f8792853568bfb2b2c
|/
o A 426bada5c67598ca65036d57d9e4b64b0c1ce7a0
$ hg debugobsolete
112478962961147124edd43549aedd1a335e44bf 7fb047a69f220c21711122dfd94305a9efb60cba 64a8289d249234b9886244d379f15e6b650b28e3 711f53bbef0bebd12eb6f0511d5e2e998b984846 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'split', 'user': 'test'}
26805aba1e600a82e93661149f2313866a221a7b be0ef73c17ade3fc89dc41701eb9fc3a91b58282 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '9', 'operation': 'replace', 'user': 'test'}
be0ef73c17ade3fc89dc41701eb9fc3a91b58282 575c4b5ec114d64b681d33f8792853568bfb2b2c 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '13', 'operation': 'replace', 'user': 'test'}
64a8289d249234b9886244d379f15e6b650b28e3 0 {7fb047a69f220c21711122dfd94305a9efb60cba} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
58e6b987bf7045fcd9c54f496396ca1d1fc81047 0 {575c4b5ec114d64b681d33f8792853568bfb2b2c} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
Change file contents via comments
$ reinit
$ hg debugdrawdag <<'EOS'
> C # A/dir1/a = 1\n2
> |\ # B/dir2/b = 34
> A B # C/dir1/c = 5
> # C/dir2/c = 6
> # C/A = a
> # C/B = b
> EOS
$ hg log -G -T '{desc} {files}'
o C A B dir1/c dir2/c
|\
| o B B dir2/b
|
o A A dir1/a
$ for f in `hg files -r C`; do
> echo FILE "$f"
> hg cat -r C "$f"
> echo
> done
FILE A
a
FILE B
b
FILE dir1/a
1
2
FILE dir1/c
5
FILE dir2/b
34
FILE dir2/c
6