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.
$ hg init a
$ echo a > a/a
$ hg --cwd a ci -Ama
adding a
$ hg clone a c
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b >> b/a
$ hg --cwd b ci -mb
Push should provide a hint when both 'default' and 'default-push' not set:
$ cd c
$ hg push --config paths.default=
abort: default repository not configured!
(see the "path" section in "hg help config")
[255]
$ cd ..
Push should push to 'default' when 'default-push' not set:
$ hg --cwd b push
pushing to $TESTTMP/a (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
Push should push to 'default-push' when set:
$ echo '[paths]' >> b/.hg/hgrc
$ echo 'default-push = ../c' >> b/.hg/hgrc
$ hg --cwd b push
pushing to $TESTTMP/c (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
But push should push to 'default' if explicitly specified (issue5000):
$ hg --cwd b push default
pushing to $TESTTMP/a (glob)
searching for changes
no changes found
[1]
Push should push to 'default-push' when 'default' is not set
$ hg -q clone a push-default-only
$ cd push-default-only
$ rm .hg/hgrc
$ touch foo
$ hg -q commit -A -m 'add foo'
$ hg --config paths.default-push=../a push
pushing to $TESTTMP/a (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
$ cd ..
Pushing to a path that isn't defined should not fall back to default
$ hg --cwd b push doesnotexist
abort: repository doesnotexist does not exist!
[255]
:pushurl is used when defined
$ hg -q clone a pushurlsource
$ hg -q clone a pushurldest
$ cd pushurlsource
Windows needs a leading slash to make a URL that passes all of the checks
$ WD=`pwd`
#if windows
$ WD="/$WD"
#endif
$ cat > .hg/hgrc << EOF
> [paths]
> default = https://example.com/not/relevant
> default:pushurl = file://$WD/../pushurldest
> EOF
$ touch pushurl
$ hg -q commit -A -m 'add pushurl'
$ hg push
pushing to file:/*/$TESTTMP/pushurlsource/../pushurldest (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
$ cd ..