demandimport: delay loading for "from a import b" with absolute_import
Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.
For example:
- it is assumed that extension X has "from P import M" for module M
under package P with absolute_import feature
- if importing module M is already delayed before loading extension
X, loading module M in extension X is delayed until actually
referring
util, cmdutil, scmutil or so of Mercurial itself should be
imported by "from . import M" style before loading extension X
- otherwise, module M is loaded immediately at loading extension X,
even if extension X itself isn't used at that "hg" command invocation
Some minor modules (e.g. filemerge or so) of Mercurial itself
aren't imported by "from . import M" style before loading
extension X. And of course, external libraries aren't, too.
This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.
To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:
1. import root module of "name" by system built-in __import__
(referred as _origimport)
2. recurse down the module chain for hierarchical "name"
This logic can be shared with non absolute_import
case. Therefore, this patch also centralizes it into chainmodules().
3. and fall through to process elements in "fromlist" for the leaf
module of "name"
Processing elements in "fromlist" is executed in the code path
after "if _pypy: .... else: ..." clause. Therefore, this patch
replaces "if _pypy:" with "elif _pypy:" to share it.
At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.
IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.
This is reason why this patch removes "errors for unknown reasons"
comment.
Environment setup for MQ
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ cat >> $HGRCPATH <<EOF
> [defaults]
> # explicit date to commit with fixed hashid
> qnew = -d "0 0"
> qrefresh = -d "0 0"
> qfold = -d "0 0"
> EOF
$ hg init
$ hg qinit
Should fail if no patches applied
(this tests also that editor is not invoked if '--edit' is not
specified)
$ hg qrefresh
no patches applied
[1]
$ hg qrefresh -e
no patches applied
[1]
$ hg qnew -m "First commit message" first-patch
$ echo aaaa > file
$ hg add file
$ HGEDITOR=cat hg qrefresh
Should display 'First commit message'
$ hg log -l1 --template "{desc}\n"
First commit message
Testing changing message with -m
(this tests also that '--edit' can be used with '--message', and
that '[committemplate] changeset' definition and commit log specific
template keyword 'extramsg' work well)
$ cat >> .hg/hgrc <<EOF
> [committemplate]
> listupfiles = {file_adds %
> "HG: added {file}\n" }{file_mods %
> "HG: changed {file}\n" }{file_dels %
> "HG: removed {file}\n" }{if(files, "",
> "HG: no files changed\n")}
>
> changeset = HG: this is customized commit template
> {desc}\n\n
> HG: Enter commit message. Lines beginning with 'HG:' are removed.
> HG: {extramsg}
> HG: --
> HG: user: {author}
> HG: branch '{branch}'\n{listupfiles}
> EOF
$ echo bbbb > file
$ HGEDITOR=cat hg qrefresh -m "Second commit message" -e
HG: this is customized commit template
Second commit message
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to use default message.
HG: --
HG: user: test
HG: branch 'default'
HG: added file
$ cat >> .hg/hgrc <<EOF
> # disable customizing for subsequent tests
> [committemplate]
> changeset =
> EOF
Should display 'Second commit message'
$ hg log -l1 --template "{desc}\n"
Second commit message
Testing changing message with -l
$ echo "Third commit message" > logfile
$ echo " This is the 3rd log message" >> logfile
$ echo bbbb > file
$ hg qrefresh -l logfile
Should display 'Third commit message\\\n This is the 3rd log message'
$ hg log -l1 --template "{desc}\n"
Third commit message
This is the 3rd log message
Testing changing message with -l-
$ hg qnew -m "First commit message" second-patch
$ echo aaaa > file2
$ hg add file2
$ echo bbbb > file2
$ (echo "Fifth commit message"; echo " This is the 5th log message") | hg qrefresh -l-
Should display 'Fifth commit message\\\n This is the 5th log message'
$ hg log -l1 --template "{desc}\n"
Fifth commit message
This is the 5th log message
Test saving last-message.txt:
$ cat > $TESTTMP/editor.sh << EOF
> echo "==== before editing"
> cat \$1
> echo "===="
> (echo; echo "test saving last-message.txt") >> \$1
> EOF
$ cat > $TESTTMP/commitfailure.py <<EOF
> from mercurial import error
> def reposetup(ui, repo):
> class commitfailure(repo.__class__):
> def commit(self, *args, **kwargs):
> raise error.Abort('emulating unexpected abort')
> repo.__class__ = commitfailure
> EOF
$ cat >> .hg/hgrc <<EOF
> [extensions]
> # this failure occurs before editor invocation
> commitfailure = $TESTTMP/commitfailure.py
> EOF
$ hg qapplied
first-patch
second-patch
$ hg tip --template "{files}\n"
file2
(test that editor is not invoked before transaction starting)
$ rm -f .hg/last-message.txt
$ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: emulating unexpected abort
[255]
$ test -f .hg/last-message.txt
[1]
(reset applied patches and directory status)
$ cat >> .hg/hgrc <<EOF
> [extensions]
> commitfailure = !
> EOF
$ hg qapplied
first-patch
$ hg status -A file2
? file2
$ rm file2
$ hg qpush -q second-patch
now at: second-patch
(test that editor is invoked and commit message is saved into
"last-message.txt")
$ cat >> .hg/hgrc <<EOF
> [hooks]
> # this failure occurs after editor invocation
> pretxncommit.unexpectedabort = false
> EOF
$ rm -f .hg/last-message.txt
$ hg status --rev "second-patch^1" -arm
A file2
$ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
==== before editing
Fifth commit message
This is the 5th log message
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to use default message.
HG: --
HG: user: test
HG: branch 'default'
HG: added file2
====
note: commit message saved in .hg/last-message.txt
transaction abort!
rollback completed
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: pretxncommit.unexpectedabort hook exited with status 1
[255]
$ cat .hg/last-message.txt
Fifth commit message
This is the 5th log message
test saving last-message.txt
Test visibility of in-memory distate changes outside transaction to
external process
$ cat > $TESTTMP/checkvisibility.sh <<EOF
> echo "===="
> hg parents --template "{rev}:{node|short}\n"
> hg status -arm
> echo "===="
> EOF
== test visibility to external editor
$ hg update -C -q first-patch
$ rm -f file2
$ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
now at: second-patch
$ echo bbbb >> file2
$ sh "$TESTTMP/checkvisibility.sh"
====
1:e30108269082
M file2
====
$ HGEDITOR="sh \"$TESTTMP/checkvisibility.sh\"" hg qrefresh -e
====
0:25e397dabed2
A file2
====
note: commit message saved in .hg/last-message.txt
transaction abort!
rollback completed
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: pretxncommit.unexpectedabort hook exited with status 1
[255]
(rebuilding at failure of qrefresh bases on rev #0, and it causes
dropping status of "file2")
$ sh "$TESTTMP/checkvisibility.sh"
====
0:25e397dabed2
====
== test visibility to precommit external hook
$ hg update -C -q
$ rm -f file2
$ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
now at: second-patch
$ echo bbbb >> file2
$ cat >> .hg/hgrc <<EOF
> [hooks]
> precommit.checkvisibility = sh "$TESTTMP/checkvisibility.sh"
> EOF
$ sh "$TESTTMP/checkvisibility.sh"
====
1:e30108269082
M file2
====
$ hg qrefresh
====
0:25e397dabed2
A file2
====
transaction abort!
rollback completed
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: pretxncommit.unexpectedabort hook exited with status 1
[255]
$ sh "$TESTTMP/checkvisibility.sh"
====
0:25e397dabed2
====
$ cat >> .hg/hgrc <<EOF
> [hooks]
> precommit.checkvisibility =
> EOF
== test visibility to pretxncommit external hook
$ hg update -C -q
$ rm -f file2
$ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
now at: second-patch
$ echo bbbb >> file2
$ cat >> .hg/hgrc <<EOF
> [hooks]
> pretxncommit.checkvisibility = sh "$TESTTMP/checkvisibility.sh"
> # make checkvisibility run before unexpectedabort
> priority.pretxncommit.checkvisibility = 10
> EOF
$ sh "$TESTTMP/checkvisibility.sh"
====
1:e30108269082
M file2
====
$ hg qrefresh
====
0:25e397dabed2
A file2
====
transaction abort!
rollback completed
qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
abort: pretxncommit.unexpectedabort hook exited with status 1
[255]
$ sh "$TESTTMP/checkvisibility.sh"
====
0:25e397dabed2
====
$ cat >> .hg/hgrc <<EOF
> [hooks]
> pretxncommit.checkvisibility =
> EOF