extensions: refuse to load extensions if minimum hg version not met
As the author of several 3rd party extensions, I frequently see bug
reports from users attempting to run my extension with an old version
of Mercurial that I no longer support in my extension. Oftentimes, the
extension will import just fine. But as soon as we run extsetup(),
reposetup(), or get into the guts of a wrapped function, we encounter
an exception and abort. Today, Mercurial will print a message about
extensions that don't have a "testedwith" declaring explicit
compatibility with the current version.
The existing mechanism is a good start. But it isn't as robust as I
would like. Specifically, Mercurial assumes compatibility by default.
This means extension authors must perform compatibility checking in
their extsetup() or we wait and see if we encounter an abort at
runtime. And, compatibility checking can involve a lot of code and
lots of error checking. It's a lot of effort for extension authors.
Oftentimes, extension authors know which versions of Mercurial there
extension works on and more importantly where it is broken.
This patch introduces a magic "minimumhgversion" attribute in
extensions. When found, the extension loading mechanism will compare
the declared version against the current Mercurial version. If the
extension explicitly states we require a newer Mercurial version, a
warning is printed and the extension isn't loaded beyond importing
the Python module. This causes a graceful failure while alerting
the user of the compatibility issue.
I would be receptive to the idea of making the failure more fatal.
However, care would need to be taken to not criple every hg command.
e.g. the user may use `hg config` to fix the hgrc and if we aborted
trying to run that, the user would effectively be locked out of `hg`!
A potential future improvement to this functionality would be to catch
ImportError for the extension/module and parse the source code for
"minimumhgversion = 'XXX'" and do similar checking. This way we could
give more information about why the extension failed to load.
Test character encoding
$ hg init t
$ cd t
we need a repo with some legacy latin-1 changesets
$ hg unbundle "$TESTDIR/bundles/legacy-encoding.hg"
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
(run 'hg update' to get a working copy)
$ hg co
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ python << EOF
> f = file('latin-1', 'w'); f.write("latin-1 e' encoded: \xe9"); f.close()
> f = file('utf-8', 'w'); f.write("utf-8 e' encoded: \xc3\xa9"); f.close()
> f = file('latin-1-tag', 'w'); f.write("\xe9"); f.close()
> EOF
should fail with encoding error
$ echo "plain old ascii" > a
$ hg st
M a
? latin-1
? latin-1-tag
? utf-8
$ HGENCODING=ascii hg ci -l latin-1
transaction abort!
rollback completed
abort: decoding near ' encoded: \xe9': 'ascii' codec can't decode byte 0xe9 in position 20: ordinal not in range(128)! (esc)
[255]
these should work
$ echo "latin-1" > a
$ HGENCODING=latin-1 hg ci -l latin-1
$ echo "utf-8" > a
$ HGENCODING=utf-8 hg ci -l utf-8
$ HGENCODING=latin-1 hg tag `cat latin-1-tag`
$ HGENCODING=latin-1 hg branch `cat latin-1-tag`
marked working directory as branch \xe9 (esc)
(branches are permanent and global, did you want a bookmark?)
$ HGENCODING=latin-1 hg ci -m 'latin1 branch'
$ hg -q rollback
$ HGENCODING=latin-1 hg branch
\xe9 (esc)
$ HGENCODING=latin-1 hg ci -m 'latin1 branch'
$ rm .hg/branch
hg log (ascii)
$ hg --encoding ascii log
changeset: 5:a52c0692f24a
branch: ?
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag ? for changeset ca661e7520de
changeset: 3:ca661e7520de
tag: ?
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: ?
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: ?
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: ????? = u'\u0440\u0442\u0443\u0442\u044c'
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': ? = u'\xe9'
hg log (latin-1)
$ hg --encoding latin-1 log
changeset: 5:a52c0692f24a
branch: \xe9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xe9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xe9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xe9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xe9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xd2\xd4\xd5\xd4\xd8 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xe9 = u'\\xe9' (esc)
hg log (utf-8)
$ hg --encoding utf-8 log
changeset: 5:a52c0692f24a
branch: \xc3\xa9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xc3\xa9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xc3\xa9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xc3\xa9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xc3\x92\xc3\x94\xc3\x95\xc3\x94\xc3\x98 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xc3\xa9 = u'\\xe9' (esc)
hg tags (ascii)
$ HGENCODING=ascii hg tags
tip 5:a52c0692f24a
? 3:ca661e7520de
hg tags (latin-1)
$ HGENCODING=latin-1 hg tags
tip 5:a52c0692f24a
\xe9 3:ca661e7520de (esc)
hg tags (utf-8)
$ HGENCODING=utf-8 hg tags
tip 5:a52c0692f24a
\xc3\xa9 3:ca661e7520de (esc)
hg tags (JSON)
$ hg tags -Tjson
[
{
"node": "a52c0692f24ad921c0a31e1736e7635a8b23b670",
"rev": 5,
"tag": "tip",
"type": ""
},
{
"node": "ca661e7520dec3f5438a63590c350bebadb04989",
"rev": 3,
"tag": "\xc3\xa9", (esc)
"type": ""
}
]
hg branches (ascii)
$ HGENCODING=ascii hg branches
? 5:a52c0692f24a
default 4:94db611b4196 (inactive)
hg branches (latin-1)
$ HGENCODING=latin-1 hg branches
\xe9 5:a52c0692f24a (esc)
default 4:94db611b4196 (inactive)
hg branches (utf-8)
$ HGENCODING=utf-8 hg branches
\xc3\xa9 5:a52c0692f24a (esc)
default 4:94db611b4196 (inactive)
$ echo '[ui]' >> .hg/hgrc
$ echo 'fallbackencoding = koi8-r' >> .hg/hgrc
hg log (utf-8)
$ HGENCODING=utf-8 hg log
changeset: 5:a52c0692f24a
branch: \xc3\xa9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xc3\xa9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xc3\xa9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xc3\xa9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xd1\x80\xd1\x82\xd1\x83\xd1\x82\xd1\x8c = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xd0\x98 = u'\\xe9' (esc)
hg log (dolphin)
$ HGENCODING=dolphin hg log
abort: unknown encoding: dolphin
(please check your locale settings)
[255]
$ HGENCODING=ascii hg branch `cat latin-1-tag`
abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc)
[255]
$ cp latin-1-tag .hg/branch
$ HGENCODING=latin-1 hg ci -m 'auto-promote legacy name'
Test roundtrip encoding of lookup tables when not using UTF-8 (issue2763)
$ HGENCODING=latin-1 hg up `cat latin-1-tag`
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..
Test roundtrip encoding/decoding of utf8b for generated data
#if hypothesis
>>> from hypothesishelpers import *
>>> from mercurial import encoding
>>> roundtrips(st.binary(), encoding.fromutf8b, encoding.toutf8b)
Round trip OK
#endif