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 EOL update
$ cat >> $HGRCPATH <<EOF
> [diff]
> git = 1
> EOF
$ seteol () {
> if [ $1 = "LF" ]; then
> EOL='\n'
> else
> EOL='\r\n'
> fi
> }
$ makerepo () {
> echo
> echo "# ==== setup repository ===="
> echo '% hg init'
> hg init repo
> cd repo
>
> cat > .hgeol <<EOF
> [patterns]
> **.txt = LF
> EOF
>
> printf "first\nsecond\nthird\n" > a.txt
> printf "f\r\n" > f
> hg commit --addremove -m 'LF commit'
>
> cat > .hgeol <<EOF
> [patterns]
> **.txt = CRLF
> f = LF
> EOF
>
> printf "first\r\nsecond\r\nthird\r\n" > a.txt
> printf "f\n" > f
> hg commit -m 'CRLF commit'
>
> cd ..
> }
$ dotest () {
> seteol $1
>
> echo
> echo "% hg clone repo repo-$1"
> hg clone --noupdate repo repo-$1
> cd repo-$1
>
> cat > .hg/hgrc <<EOF
> [extensions]
> eol =
> EOF
>
> hg update
>
> echo '% a.txt (before)'
> cat a.txt
>
> printf "first${EOL}third${EOL}" > a.txt
>
> echo '% a.txt (after)'
> cat a.txt
> echo '% hg diff'
> hg diff
>
> echo '% hg update 0'
> hg update 0
>
> echo '% a.txt'
> cat a.txt
> echo '% hg diff'
> hg diff
>
>
> cd ..
> rm -r repo-$1
> }
$ makerepo
# ==== setup repository ====
% hg init
adding .hgeol
adding a.txt
adding f
$ dotest LF
% hg clone repo repo-LF
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
% a.txt (before)
first\r (esc)
second\r (esc)
third\r (esc)
% a.txt (after)
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg update 0
merging a.txt
2 files updated, 1 files merged, 0 files removed, 0 files unresolved
% a.txt
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first
-second
third
$ dotest CRLF
% hg clone repo repo-CRLF
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
% a.txt (before)
first\r (esc)
second\r (esc)
third\r (esc)
% a.txt (after)
first\r (esc)
third\r (esc)
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg update 0
merging a.txt
2 files updated, 1 files merged, 0 files removed, 0 files unresolved
% a.txt
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first
-second
third
Test in repo using eol extension, while keeping an eye on how filters are
applied:
$ cd repo
$ hg up -q -c -r null
$ cat > .hg/hgrc <<EOF
> [extensions]
> eol =
> EOF
Update to revision 0 which has no .hgeol, shouldn't use any filters, and
obviously should leave things as tidy as they were before the clean update.
$ hg up -c -r 0 -v --debug
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: 000000000000, local: 000000000000+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
.hgeol: remote created -> g
getting .hgeol
filtering .hgeol through isbinary
a.txt: remote created -> g
getting a.txt
filtering a.txt through tolf
f: remote created -> g
getting f
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg st
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ hg ci -m b
Merge changes that apply a filter to f:
$ hg merge 1
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st
M .hgeol
M a.txt
M f
$ hg diff
diff --git a/.hgeol b/.hgeol
--- a/.hgeol
+++ b/.hgeol
@@ -1,2 +1,3 @@
[patterns]
-**.txt = LF
+**.txt = CRLF
+f = LF
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,3 @@
-first
-second
-third
+first\r (esc)
+second\r (esc)
+third\r (esc)
diff --git a/f b/f
--- a/f
+++ b/f
@@ -1,1 +1,1 @@
-f\r (esc)
+f
Abort the merge with up -C to revision 0.
Note that files are filtered correctly for revision 0: f is not filtered, a.txt
is filtered with tolf, and everything is left tidy.
$ touch .hgeol * # ensure consistent dirtyness checks ignoring dirstate
$ hg up -C -r 0 -v --debug
eol: detected change in .hgeol
resolving manifests
branchmerge: False, force: True, partial: False
ancestor: 1db78bdd3bd6+, local: 1db78bdd3bd6+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
.hgeol: remote is newer -> g
getting .hgeol
filtering .hgeol through isbinary
a.txt: remote is newer -> g
getting a.txt
filtering a.txt through tolf
f: remote is newer -> g
getting f
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch .hgeol *
$ hg st --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
skip updating dirstate: identity mismatch (?)
$ hg diff
Things were clean, and updating again will not change anything:
$ touch .hgeol *
$ hg up -C -r 0 -v --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
resolving manifests
branchmerge: False, force: True, partial: False
ancestor: 15cbdf8ca3db+, local: 15cbdf8ca3db+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
starting 4 threads for background file closing (?)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch .hgeol *
$ hg st --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
$ cd ..
$ rm -r repo