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 cvs no-root
This is https://bz.mercurial-scm.org/1148
and https://bz.mercurial-scm.org/1447
$ cvscall()
> {
> cvs -f "$@" > /dev/null
> }
$ cat <<EOF >> $HGRCPATH
> [extensions]
> convert =
> [convert]
> cvsps.cache = 0
> EOF
create cvs repository
$ mkdir cvsrepo
$ cd cvsrepo
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsrepo
$ cvscall -q -d "$CVSROOT" init
Create a new project
$ mkdir src
$ cd src
$ echo "1" > a
$ echo "1" > b
$ cvscall import -m "init" src v0 r0 | sort
$ cd ..
$ cvscall co src
cvs checkout: Updating src
$ cd src
Branch the project
$ cvscall tag -b BRANCH
cvs tag: Tagging .
$ cvscall up -r BRANCH > /dev/null
cvs update: Updating .
Modify file a, then b, then a
$ sleep 1
$ echo "2" > a
$ cvscall ci -m "mod a"
cvs commit: Examining .
$ echo "2" > b
$ cvscall ci -m "mod b"
cvs commit: Examining .
$ sleep 1
$ echo "3" > a
$ cvscall ci -m "mod a again"
cvs commit: Examining .
Convert
$ cd ..
$ hg convert src
assuming destination src-hg
initializing destination src-hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
7 log entries
creating changesets
5 changeset entries
sorting...
converting...
4 Initial revision
3 init
2 mod a
1 mod b
0 mod a again
updating tags
Check the result
$ hg -R src-hg log -G --template '{rev} ({branches}) {desc} files: {files}\n'
o 5 () update tags files: .hgtags
|
| o 4 (BRANCH) mod a again files: a
| |
| o 3 (BRANCH) mod b files: b
| |
| o 2 (BRANCH) mod a files: a
| |
| o 1 (v0) init files:
|/
o 0 () Initial revision files: a b
issue 1447
$ cvscall()
> {
> cvs -f "$@" > /dev/null
> sleep 1
> }
$ cvsci()
> {
> cvs -f ci "$@" >/dev/null
> sleep 1
> }
$ cvscall -Q -d `pwd`/cvsmaster2 init
$ cd cvsmaster2
$ CVSROOT=`pwd`
$ export CVSROOT
$ mkdir foo
$ cd ..
$ cvscall -Q co -d cvswork2 foo
$ cd cvswork2
$ echo foo > a.txt
$ echo bar > b.txt
$ cvscall -Q add a.txt b.txt
$ cvsci -m "Initial commit"
cvs commit: Examining .
$ echo foo > b.txt
$ cvsci -m "Fix b on HEAD"
cvs commit: Examining .
$ echo bar > a.txt
$ cvsci -m "Small fix in a on HEAD"
cvs commit: Examining .
$ cvscall -Q tag -b BRANCH
$ cvscall -Q up -P -rBRANCH
$ echo baz > b.txt
$ cvsci -m "Change on BRANCH in b"
cvs commit: Examining .
$ hg debugcvsps -x --parents foo
collecting CVS rlog
5 log entries
creating changesets
4 changeset entries
---------------------
PatchSet 1
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Log:
Initial commit
Members:
a.txt:INITIAL->1.1
b.txt:INITIAL->1.1
---------------------
PatchSet 2
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: BRANCH
Parent: 1
Log:
Fix b on HEAD
Members:
b.txt:1.1->1.2
---------------------
PatchSet 3
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: BRANCH
Parent: 2
Log:
Small fix in a on HEAD
Members:
a.txt:1.1->1.2
---------------------
PatchSet 4
Date: * (glob)
Author: * (glob)
Branch: BRANCH
Tag: (none)
Parent: 3
Log:
Change on BRANCH in b
Members:
b.txt:1.2->1.2.2.1
$ cd ..