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.
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> }
$ initrepo
log before edit
$ hg log --graph
@ changeset: 5:652413bf663e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
edit the history
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF | fixbundle
> drop 177f92b77385 c
> pick e860deea161a e
> pick 652413bf663e f
> pick 055a42cdd887 d
> EOF
log after edit
$ hg log --graph
@ changeset: 4:f518305ce889
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:a4f7421b80f7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Check histedit_source
$ hg log --debug --rev f518305ce889
changeset: 4:f518305ce889c07cb5bd05522176d75590ef3324
tag: tip
phase: draft
parent: 3:a4f7421b80f79fcc59fff01bcbf4a53d127dd6d3
parent: -1:0000000000000000000000000000000000000000
manifest: 4:d3d4f51c157ff242c32ff745d4799aaa26ccda44
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files+: d
extra: branch=default
extra: histedit_source=055a42cdd88768532f9cf79daa407fc8d138de9b
description:
d
manifest after edit
$ hg manifest
a
b
d
e
f
Drop the last changeset
$ hg histedit ee283cb5f2d5 --commands - 2>&1 << EOF | fixbundle
> pick ee283cb5f2d5 e
> pick a4f7421b80f7 f
> drop f518305ce889 d
> EOF
$ hg log --graph
@ changeset: 3:a4f7421b80f7
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ hg histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
hg: parse error: missing rules for changeset a4f7421b80f7
(use "drop a4f7421b80f7" to discard, see also: 'hg help -e histedit.config')
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> EOF
hg: parse error: no rules provided
(use strip extension to remove commits)
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
$ hg log --graph
@ changeset: 1:e99c679bf03e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a