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.
#require no-chg
$ filterlog () {
> sed -e 's!^[0-9/]* [0-9:]* ([0-9]*)>!YYYY/MM/DD HH:MM:SS (PID)>!'
> }
ensure that failing ui.atexit handlers report sensibly
$ cat > $TESTTMP/bailatexit.py <<EOF
> from mercurial import util
> def bail():
> raise RuntimeError('ui.atexit handler exception')
>
> def extsetup(ui):
> ui.atexit(bail)
> EOF
$ hg -q --config extensions.bailatexit=$TESTTMP/bailatexit.py \
> help help
hg help [-eck] [-s PLATFORM] [TOPIC]
show help for a given topic or a help overview
error in exit handlers:
Traceback (most recent call last):
File "*/mercurial/dispatch.py", line *, in _runexithandlers (glob) (no-pyoxidizer !)
File "mercurial.dispatch", line *, in _runexithandlers (glob) (pyoxidizer !)
func(*args, **kwargs)
File "$TESTTMP/bailatexit.py", line *, in bail (glob)
raise RuntimeError('ui.atexit handler exception')
RuntimeError: ui.atexit handler exception
[255]
$ rm $TESTTMP/bailatexit.py
another bad extension
$ echo 'raise Exception("bit bucket overflow")' > badext.py
$ abspathexc=`pwd`/badext.py
$ cat >baddocext.py <<EOF
> """
> baddocext is bad
> """
> EOF
$ abspathdoc=`pwd`/baddocext.py
$ cat <<EOF >> $HGRCPATH
> [extensions]
> gpg =
> hgext.gpg =
> badext = $abspathexc
> baddocext = $abspathdoc
> badext2 =
> EOF
$ hg -q help help 2>&1 |grep extension
*** failed to import extension "badext" from $TESTTMP/badext.py: bit bucket overflow
*** failed to import extension "badext2": No module named 'badext2' (py3 !)
show traceback
$ hg -q help help --traceback 2>&1 | egrep ' extension|^Exception|Traceback|ImportError|ModuleNotFound'
*** failed to import extension "badext" from $TESTTMP/badext.py: bit bucket overflow
Traceback (most recent call last):
Exception: bit bucket overflow
*** failed to import extension "badext2": No module named 'badext2' (py3 !)
Traceback (most recent call last):
ImportError: No module named 'hgext.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext.badext2' (py36 !)
Traceback (most recent call last): (py3 !)
ImportError: No module named 'hgext3rd.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext3rd.badext2' (py36 !)
Traceback (most recent call last): (py3 !)
ImportError: No module named 'badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'badext2' (py36 !)
names of extensions failed to load can be accessed via extensions.notloaded()
$ cat <<EOF > showbadexts.py
> from mercurial import commands, extensions, registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'showbadexts', norepo=True)
> def showbadexts(ui, *pats, **opts):
> ui.write(b'BADEXTS: %s\n' % b' '.join(sorted(extensions.notloaded())))
> EOF
$ hg --config extensions.badexts=showbadexts.py showbadexts 2>&1 | grep '^BADEXTS'
BADEXTS: badext badext2
#if no-extraextensions
show traceback for ImportError of hgext.name if devel.debug.extensions is set
$ (hg help help --traceback --debug --config devel.debug.extensions=yes 2>&1) \
> | grep -v '^ ' \
> | filterlog \
> | egrep 'extension..[^p]|^Exception|Traceback|ImportError|^YYYY|not import|ModuleNotFound'
YYYY/MM/DD HH:MM:SS (PID)> loading extensions
YYYY/MM/DD HH:MM:SS (PID)> - processing 5 entries
YYYY/MM/DD HH:MM:SS (PID)> - loading extension: gpg
YYYY/MM/DD HH:MM:SS (PID)> > gpg extension loaded in * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - validating extension tables: gpg
YYYY/MM/DD HH:MM:SS (PID)> - invoking registered callbacks: gpg
YYYY/MM/DD HH:MM:SS (PID)> > callbacks completed in * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - loading extension: badext
*** failed to import extension "badext" from $TESTTMP/badext.py: bit bucket overflow
Traceback (most recent call last):
Exception: bit bucket overflow
YYYY/MM/DD HH:MM:SS (PID)> - loading extension: baddocext
YYYY/MM/DD HH:MM:SS (PID)> > baddocext extension loaded in * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - validating extension tables: baddocext
YYYY/MM/DD HH:MM:SS (PID)> - invoking registered callbacks: baddocext
YYYY/MM/DD HH:MM:SS (PID)> > callbacks completed in * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - loading extension: badext2
YYYY/MM/DD HH:MM:SS (PID)> - could not import hgext.badext2 (No module named *badext2*): trying hgext3rd.badext2 (glob)
Traceback (most recent call last):
ImportError: No module named 'hgext.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext.badext2' (py36 !)
YYYY/MM/DD HH:MM:SS (PID)> - could not import hgext3rd.badext2 (No module named *badext2*): trying badext2 (glob)
Traceback (most recent call last):
ImportError: No module named 'hgext.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext.badext2' (py36 !)
Traceback (most recent call last): (py3 !)
ImportError: No module named 'hgext3rd.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext3rd.badext2' (py36 !)
*** failed to import extension "badext2": No module named 'badext2' (py3 !)
Traceback (most recent call last):
ImportError: No module named 'hgext.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext.badext2' (py36 !)
Traceback (most recent call last): (py3 !)
ImportError: No module named 'hgext3rd.badext2' (py3 no-py36 !)
ModuleNotFoundError: No module named 'hgext3rd.badext2' (py36 !)
Traceback (most recent call last): (py3 !)
ModuleNotFoundError: No module named 'badext2' (py36 !)
ImportError: No module named 'badext2' (py3 no-py36 !)
YYYY/MM/DD HH:MM:SS (PID)> > loaded 2 extensions, total time * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - loading configtable attributes
YYYY/MM/DD HH:MM:SS (PID)> - executing uisetup hooks
YYYY/MM/DD HH:MM:SS (PID)> - running uisetup for gpg
YYYY/MM/DD HH:MM:SS (PID)> > uisetup for gpg took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - running uisetup for baddocext
YYYY/MM/DD HH:MM:SS (PID)> > uisetup for baddocext took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> > all uisetup took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - executing extsetup hooks
YYYY/MM/DD HH:MM:SS (PID)> - running extsetup for gpg
YYYY/MM/DD HH:MM:SS (PID)> > extsetup for gpg took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - running extsetup for baddocext
YYYY/MM/DD HH:MM:SS (PID)> > extsetup for baddocext took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> > all extsetup took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - executing remaining aftercallbacks
YYYY/MM/DD HH:MM:SS (PID)> > remaining aftercallbacks completed in * (glob)
YYYY/MM/DD HH:MM:SS (PID)> - loading extension registration objects
YYYY/MM/DD HH:MM:SS (PID)> > extension registration object loading took * (glob)
YYYY/MM/DD HH:MM:SS (PID)> > extension baddocext take a total of * to load (glob)
YYYY/MM/DD HH:MM:SS (PID)> > extension gpg take a total of * to load (glob)
YYYY/MM/DD HH:MM:SS (PID)> extension loading complete
#endif
confirm that there's no crash when an extension's documentation is bad
$ hg help --keyword baddocext
*** failed to import extension "badext" from $TESTTMP/badext.py: bit bucket overflow
*** failed to import extension "badext2": No module named 'badext2' (py3 !)
Topics:
extensions Using Additional Features