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.
Testing narrow clones when changesets modifying a matching file exist on
multiple branches
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [narrow]
> serveellipses=True
> EOF
$ hg branch default
marked working directory as branch default
(branches are permanent and global, did you want a bookmark?)
$ for x in `$TESTDIR/seq.py 10`; do
> echo $x > "f$x"
> hg add "f$x"
> hg commit -m "Add $x"
> done
$ hg branch release-v1
marked working directory as branch release-v1
(branches are permanent and global, did you want a bookmark?)
$ hg commit -m "Start release for v1"
$ hg update default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ for x in `$TESTDIR/seq.py 10`; do
> echo "$x v2" > "f$x"
> hg commit -m "Update $x to v2"
> done
$ hg update release-v1
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v1
marked working directory as branch release-v1
$ for x in `$TESTDIR/seq.py 1 5`; do
> echo "$x v1 hotfix" > "f$x"
> hg commit -m "Hotfix $x in v1"
> done
$ hg update default
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v2
marked working directory as branch release-v2
$ hg commit -m "Start release for v2"
$ hg update default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch default
marked working directory as branch default
$ for x in `$TESTDIR/seq.py 10`; do
> echo "$x v3" > "f$x"
> hg commit -m "Update $x to v3"
> done
$ hg update release-v2
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v2
marked working directory as branch release-v2
$ for x in `$TESTDIR/seq.py 4 9`; do
> echo "$x v2 hotfix" > "f$x"
> hg commit -m "Hotfix $x in v2"
> done
$ hg heads -T '{rev} <- {p1rev} ({branch}): {desc}\n'
42 <- 41 (release-v2): Hotfix 9 in v2
36 <- 35 (default): Update 10 to v3
25 <- 24 (release-v1): Hotfix 5 in v1
$ cd ..
We now have 3 branches: default, which has v3 of all files, release-v1 which
has v1 of all files, and release-v2 with v2 of all files.
Narrow clone which should get all branches
$ hg clone --narrow ssh://user@dummy/master narrow --include "f5"
requesting all changes
adding changesets
adding manifests
adding file changes
added 12 changesets with 5 changes to 1 files (+2 heads)
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg log -G -T "{if(ellipsis, '...')}{node|short} ({branch}): {desc}\n"
o ...031f516143fe (release-v2): Hotfix 9 in v2
|
o 9cd7f7bb9ca1 (release-v2): Hotfix 5 in v2
|
o ...37bbc88f3ef0 (release-v2): Hotfix 4 in v2
|
| @ ...dae2f368ca07 (default): Update 10 to v3
| |
| o 9c224e89cb31 (default): Update 5 to v3
| |
| o ...04fb59c7c9dc (default): Update 4 to v3
|/
| o b2253e82401f (release-v1): Hotfix 5 in v1
| |
| o ...960ac37d74fd (release-v1): Hotfix 4 in v1
| |
o | 986298e3f347 (default): Update 5 to v2
| |
o | ...75d539c667ec (default): Update 4 to v2
|/
o 04c71bd5707f (default): Add 5
|
o ...881b3891d041 (default): Add 4
Narrow clone the first file, hitting edge condition where unaligned
changeset and manifest revnums cross branches.
$ hg clone --narrow ssh://user@dummy/master narrow --include "f1"
requesting all changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 4 changes to 1 files (+2 heads)
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg log -G -T "{if(ellipsis, '...')}{node|short} ({branch}): {desc}\n"
o ...031f516143fe (release-v2): Hotfix 9 in v2
|
| @ ...dae2f368ca07 (default): Update 10 to v3
| |
| o 1f5d184b8e96 (default): Update 1 to v3
|/
| o ...b2253e82401f (release-v1): Hotfix 5 in v1
| |
| o 133502f6b7e5 (release-v1): Hotfix 1 in v1
| |
o | ...79165c83d644 (default): Update 10 to v2
| |
o | c7b7a5f2f088 (default): Update 1 to v2
| |
| o ...f0531a3db7a9 (release-v1): Start release for v1
|/
o ...6a3f0f0abef3 (default): Add 10
|
o e012ac15eaaa (default): Add 1