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 interaction of sparse and narrow when both are enabled on the client
side and we do a non-ellipsis clone
#testcases tree flat
$ . "$TESTDIR/narrow-library.sh"
$ cat << EOF >> $HGRCPATH
> [extensions]
> sparse =
> EOF
#if tree
$ cat << EOF >> $HGRCPATH
> [experimental]
> treemanifest = 1
> EOF
#endif
$ hg init master
$ cd master
$ mkdir inside
$ echo 'inside' > inside/f
$ hg add inside/f
$ hg commit -m 'add inside'
$ mkdir widest
$ echo 'widest' > widest/f
$ hg add widest/f
$ hg commit -m 'add widest'
$ mkdir outside
$ echo 'outside' > outside/f
$ hg add outside/f
$ hg commit -m 'add outside'
$ cd ..
narrow clone the inside file
$ hg clone --narrow ssh://user@dummy/master narrow --include inside/f
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 1 changes to 1 files
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg tracked
I path:inside/f
$ hg files
inside/f
XXX: we should have a flag in `hg debugsparse` to list the sparse profile
$ test -f .hg/sparse
[1]
$ hg debugrequires
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
generaldelta
narrowhg-experimental
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest (tree !)
$ hg debugrebuilddirstate
We only make the following assertions for the flat test case since in the
treemanifest test case debugsparse fails with "path ends in directory
separator: outside/" which seems like a bug unrelated to the regression this is
testing for.
#if flat
widening with both sparse and narrow is possible
$ cat >> .hg/hgrc <<EOF
> [extensions]
> sparse =
> narrow =
> EOF
$ hg debugsparse -X outside/f -X widest/f
$ hg tracked -q --addinclude outside/f
$ find . -name .hg -prune -o -type f -print | sort
./inside/f
$ hg debugsparse -d outside/f
$ find . -name .hg -prune -o -type f -print | sort
./inside/f
./outside/f
#endif