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 cloning with the EOL extension
$ cat >> $HGRCPATH <<EOF
> [extensions]
> eol =
>
> [eol]
> native = CRLF
> EOF
setup repository
$ hg init repo
$ cd repo
$ cat > .hgeol <<EOF
> [patterns]
> **.txt = native
> EOF
$ printf "first\r\nsecond\r\nthird\r\n" > a.txt
$ hg commit --addremove -m 'checkin'
adding .hgeol
adding a.txt
Test commit of removed .hgeol and how it immediately makes the automatic
changes explicit and committable.
$ cd ..
$ hg clone repo repo-2
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo-2
$ cat a.txt
first\r (esc)
second\r (esc)
third\r (esc)
$ hg cat a.txt
first
second
third
$ hg remove .hgeol
$ touch a.txt * # ensure consistent st dirtyness checks, ignoring dirstate timing
$ hg st -v --debug
M a.txt
R .hgeol
$ hg commit -m 'remove eol'
$ hg exp
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 3c20c2d90333b6ecdc8f7aa8f9b73223c7c7a608
# Parent 90f94e2cf4e24628afddd641688dfe4cd476d6e4
remove eol
diff -r 90f94e2cf4e2 -r 3c20c2d90333 .hgeol
--- a/.hgeol Thu Jan 01 00:00:00 1970 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,2 +0,0 @@
-[patterns]
-**.txt = native
diff -r 90f94e2cf4e2 -r 3c20c2d90333 a.txt
--- a/a.txt Thu Jan 01 00:00:00 1970 +0000
+++ b/a.txt Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,3 @@
-first
-second
-third
+first\r (esc)
+second\r (esc)
+third\r (esc)
$ hg push --quiet
$ cd ..
Test clone of repo with .hgeol in working dir, but no .hgeol in default
checkout revision tip. The repo is correctly updated to be consistent and have
the exact content checked out without filtering, ignoring the current .hgeol in
the source repo:
$ cat repo/.hgeol
[patterns]
**.txt = native
$ hg clone repo repo-3 -v --debug
linked 7 files
updating to branch default
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: 000000000000, local: 000000000000+, remote: 3c20c2d90333
calling hook preupdate.eol: hgext.eol.preupdate
a.txt: remote created -> g
getting a.txt
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
updating the branch cache
$ cd repo-3
$ cat a.txt
first\r (esc)
second\r (esc)
third\r (esc)
Test clone of revision with .hgeol
$ cd ..
$ hg clone -r 0 repo repo-4
adding changesets
adding manifests
adding file changes
added 1 changesets with 2 changes to 2 files
new changesets 90f94e2cf4e2
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo-4
$ cat .hgeol
[patterns]
**.txt = native
$ cat a.txt
first\r (esc)
second\r (esc)
third\r (esc)
$ cd ..