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.
#testcases abortcommand abortflag
#if abortflag
$ cat >> $HGRCPATH <<EOF
> [alias]
> abort = merge --abort
> EOF
#endif
$ addcommit () {
> echo $1 > $1
> hg add $1
> hg commit -d "${2} 0" -m $1
> }
$ commit () {
> hg commit -d "${2} 0" -m $1
> }
$ hg init a
$ cd a
$ addcommit "A" 0
$ addcommit "B" 1
$ echo "C" >> A
$ commit "C" 2
$ hg update -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo "D" >> A
$ commit "D" 3
created new head
State before the merge
$ hg status
$ hg id
e45016d2b3d3 tip
$ hg summary
parent: 3:e45016d2b3d3 tip
D
branch: default
commit: (clean)
update: 2 new changesets, 2 branch heads (merge)
phases: 4 draft
Testing the abort functionality first in case of conflicts
$ hg abort
abort: no merge in progress (abortflag !)
abort: no operation in progress (abortcommand !)
[20]
$ hg merge
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg merge --abort e4501
abort: cannot specify a node with --abort
[10]
$ hg merge --abort --rev e4501
abort: cannot specify both --abort and --rev
[10]
#if abortcommand
when in dry-run mode
$ hg abort --dry-run
merge in progress, will be aborted
#endif
$ hg abort
aborting the merge, updating back to e45016d2b3d3
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
Checking that we got back in the same state
$ hg status
? A.orig
$ hg id
e45016d2b3d3 tip
$ hg summary
parent: 3:e45016d2b3d3 tip
D
branch: default
commit: 1 unknown (clean)
update: 2 new changesets, 2 branch heads (merge)
phases: 4 draft
Merging a conflict araises
$ hg merge
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
Correct the conflict without marking the file as resolved
$ echo "ABCD" > A
$ hg commit -m "Merged"
abort: unresolved merge conflicts (see 'hg help resolve')
[20]
Mark the conflict as resolved and commit
$ hg resolve -m A
(no more unresolved files)
$ hg commit -m "Merged"
Test that if a file is removed but not marked resolved, the commit still fails
(issue4972)
$ hg up ".^"
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 2
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg rm --force A
$ hg commit -m merged
abort: unresolved merge conflicts (see 'hg help resolve')
[20]
$ hg resolve -ma
(no more unresolved files)
$ hg commit -m merged
created new head
Testing the abort functionality in case of no conflicts
$ hg update -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ addcommit "E" 4
created new head
$ hg id
68352a18a7c4 tip
$ hg merge -r 4
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg merge --preview --abort
abort: cannot specify both --abort and --preview
[10]
$ hg abort
aborting the merge, updating back to 68352a18a7c4
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg id
68352a18a7c4 tip
$ cd ..