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 for old histedit issue #6:
editing a changeset without any actual change would corrupt the repository
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> dir="$1"
> comment="$2"
> if [ -n "${comment}" ]; then
> echo % ${comment}
> echo % ${comment} | sed 's:.:-:g'
> fi
> hg init ${dir}
> cd ${dir}
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> }
$ geneditor ()
> {
> # generate an editor script for selecting changesets to be edited
> choice=$1 # changesets that should be edited (using sed line ranges)
> cat <<EOF | sed 's:^....::'
> # editing the rules, replacing 'pick' with 'edit' for the chosen lines
> sed '${choice}s:^pick:edit:' "\$1" > "\${1}.tmp"
> mv "\${1}.tmp" "\$1"
> # displaying the resulting rules, minus comments and empty lines
> sed '/^#/d;/^$/d;s:^:| :' "\$1" >&2
> EOF
> }
$ startediting ()
> {
> # begin an editing session
> choice="$1" # changesets that should be edited
> number="$2" # number of changesets considered (from tip)
> comment="$3"
> geneditor "${choice}" > edit.sh
> echo % start editing the history ${comment}
> HGEDITOR="sh ./edit.sh" hg histedit -- -${number} 2>&1 | fixbundle
> }
$ continueediting ()
> {
> # continue an edit already in progress
> editor="$1" # message editor when finalizing editing
> comment="$2"
> echo % finalize changeset editing ${comment}
> HGEDITOR=${editor} hg histedit --continue 2>&1 | fixbundle
> }
$ graphlog ()
> {
> comment="${1:-log}"
> echo % "${comment}"
> hg log -G --template '{rev} {node} \"{desc|firstline}\"\n'
> }
$ initrepo r1 "test editing with no change"
% test editing with no change
-----------------------------
$ cd r1
$ graphlog "log before editing"
% log before editing
@ 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f"
|
o 4 e860deea161a2f77de56603b340ebbb4536308ae "e"
|
o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d"
|
o 2 177f92b773850b59254aa5e923436f921b55483b "c"
|
o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b"
|
o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a"
$ startediting 2 3 "(not changing anything)" # edit the 2nd of 3 changesets
% start editing the history (not changing anything)
| pick 055a42cdd887 3 d
| edit e860deea161a 4 e
| pick 652413bf663e 5 f
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
Editing (e860deea161a), commit as needed now to split the change
(to edit e860deea161a, `hg histedit --continue` after making changes)
$ continueediting true "(leaving commit message unaltered)"
% finalize changeset editing (leaving commit message unaltered)
check state of working copy
$ hg id
794fe033d0a0 tip
$ graphlog "log after history editing"
% log after history editing
@ 5 794fe033d0a030f8df77c5de945fca35c9181c30 "f"
|
o 4 04d2fab980779f332dec458cc944f28de8b43435 "e"
|
o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d"
|
o 2 177f92b773850b59254aa5e923436f921b55483b "c"
|
o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b"
|
o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a"
$ cd ..
$ initrepo r2 "test editing with no change, then abort"
% test editing with no change, then abort
-----------------------------------------
$ cd r2
$ graphlog "log before editing"
% log before editing
@ 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f"
|
o 4 e860deea161a2f77de56603b340ebbb4536308ae "e"
|
o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d"
|
o 2 177f92b773850b59254aa5e923436f921b55483b "c"
|
o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b"
|
o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a"
$ startediting 1,2 3 "(not changing anything)" # edit the 1st two of 3 changesets
% start editing the history (not changing anything)
| edit 055a42cdd887 3 d
| edit e860deea161a 4 e
| pick 652413bf663e 5 f
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
Editing (055a42cdd887), commit as needed now to split the change
(to edit 055a42cdd887, `hg histedit --continue` after making changes)
$ continueediting true "(leaving commit message unaltered)"
% finalize changeset editing (leaving commit message unaltered)
Editing (e860deea161a), commit as needed now to split the change
(to edit e860deea161a, `hg histedit --continue` after making changes)
$ graphlog "log after first edit"
% log after first edit
@ 6 e5ae3ca2f1ffdbd89ec41ebc273a231f7c3022f2 "d"
|
| o 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f"
| |
| o 4 e860deea161a2f77de56603b340ebbb4536308ae "e"
| |
| o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d"
|/
o 2 177f92b773850b59254aa5e923436f921b55483b "c"
|
o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b"
|
o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a"
abort editing session, after first forcibly updating away
$ hg up 0
abort: histedit in progress
(use 'hg histedit --continue' or 'hg histedit --abort')
[20]
$ mv .hg/histedit-state .hg/histedit-state-ignore
$ hg up 0
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ mv .hg/histedit-state-ignore .hg/histedit-state
$ hg sum
parent: 0:cb9a9f314b8b
a
branch: default
commit: 1 added, 1 unknown (new branch head)
update: 6 new changesets (update)
phases: 7 draft
hist: 2 remaining (histedit --continue)
$ hg histedit --abort 2>&1 | fixbundle
modified files should survive the abort when we've moved away already
$ hg st
A e
? edit.sh
$ graphlog "log after abort"
% log after abort
o 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f"
|
o 4 e860deea161a2f77de56603b340ebbb4536308ae "e"
|
o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d"
|
o 2 177f92b773850b59254aa5e923436f921b55483b "c"
|
o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b"
|
@ 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a"
aborting and not changing files can skip mentioning updating (no) files
$ hg up
5 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg commit --close-branch -m 'closebranch'
$ startediting 1 1 "(not changing anything)" # edit the 3rd of 3 changesets
% start editing the history (not changing anything)
| edit 292aec348d9e 6 closebranch
Editing (292aec348d9e), commit as needed now to split the change
(to edit 292aec348d9e, `hg histedit --continue` after making changes)
$ hg histedit --abort
$ cd ..