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.
#require symlink
== tests added in 0.7 ==
$ hg init test-symlinks-0.7; cd test-symlinks-0.7;
$ touch foo; ln -s foo bar; ln -s nonexistent baz
import with add and addremove -- symlink walking should _not_ screwup.
$ hg add
adding bar
adding baz
adding foo
$ hg forget bar baz foo
$ hg addremove
adding bar
adding baz
adding foo
commit -- the symlink should _not_ appear added to dir state
$ hg commit -m 'initial'
$ touch bomb
again, symlink should _not_ show up on dir state
$ hg addremove
adding bomb
Assert screamed here before, should go by without consequence
$ hg commit -m 'is there a bug?'
$ cd ..
== fifo & ignore ==
$ hg init test; cd test;
$ mkdir dir
$ touch a.c dir/a.o dir/b.o
test what happens if we want to trick hg
$ hg commit -A -m 0
adding a.c
adding dir/a.o
adding dir/b.o
$ echo "relglob:*.o" > .hgignore
$ rm a.c
$ rm dir/a.o
$ rm dir/b.o
$ mkdir dir/a.o
$ ln -s nonexistent dir/b.o
$ mkfifo a.c
it should show a.c, dir/a.o and dir/b.o deleted
$ hg status
M dir/b.o
! a.c
! dir/a.o
? .hgignore
$ hg status a.c
a.c: unsupported file type (type is fifo)
! a.c
$ cd ..
== symlinks from outside the tree ==
test absolute path through symlink outside repo
$ p=`pwd`
$ hg init x
$ ln -s x y
$ cd x
$ touch f
$ hg add f
$ hg status "$p"/y/f
A f
try symlink outside repo to file inside
$ ln -s x/f ../z
this should fail
$ hg status ../z && { echo hg mistakenly exited with status 0; exit 1; } || :
abort: ../z not under root '$TESTTMP/x'
$ cd ..
== cloning symlinks ==
$ hg init clone; cd clone;
try cloning symlink in a subdir
1. commit a symlink
$ mkdir -p a/b/c
$ cd a/b/c
$ ln -s /path/to/symlink/source demo
$ cd ../../..
$ hg stat
? a/b/c/demo
$ hg commit -A -m 'add symlink in a/b/c subdir'
adding a/b/c/demo
2. clone it
$ cd ..
$ hg clone clone clonedest
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
== symlink and git diffs ==
git symlink diff
$ cd clonedest
$ hg diff --git -r null:tip
diff --git a/a/b/c/demo b/a/b/c/demo
new file mode 120000
--- /dev/null
+++ b/a/b/c/demo
@@ -0,0 +1,1 @@
+/path/to/symlink/source
\ No newline at end of file
$ hg export --git tip > ../sl.diff
import git symlink diff
$ hg rm a/b/c/demo
$ hg commit -m'remove link'
$ hg import ../sl.diff
applying ../sl.diff
$ hg diff --git -r 1:tip
diff --git a/a/b/c/demo b/a/b/c/demo
new file mode 120000
--- /dev/null
+++ b/a/b/c/demo
@@ -0,0 +1,1 @@
+/path/to/symlink/source
\ No newline at end of file
== symlinks and addremove ==
directory moved and symlinked
$ mkdir foo
$ touch foo/a
$ hg ci -Ama
adding foo/a
$ mv foo bar
$ ln -s bar foo
$ hg status
! foo/a
? bar/a
? foo
now addremove should remove old files
$ hg addremove
adding bar/a
adding foo
removing foo/a
commit and update back
$ hg ci -mb
$ hg up '.^'
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg up tip
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..
== root of repository is symlinked ==
$ hg init root
$ ln -s root link
$ cd root
$ echo foo > foo
$ hg status
? foo
$ hg status ../link
? foo
$ hg add foo
$ hg cp foo "$TESTTMP/link/bar"
foo has not been committed yet, so no copy data will be stored for bar.
$ cd ..
$ hg init b
$ cd b
$ ln -s nothing dangling
$ hg commit -m 'commit symlink without adding' dangling
abort: dangling: file not tracked!
[255]
$ hg add dangling
$ hg commit -m 'add symlink'
$ hg tip -v
changeset: 0:cabd88b706fc
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: dangling
description:
add symlink
$ hg manifest --debug
2564acbe54bbbedfbf608479340b359f04597f80 644 @ dangling
$ readlink.py dangling
dangling -> nothing
$ rm dangling
$ ln -s void dangling
$ hg commit -m 'change symlink'
$ readlink.py dangling
dangling -> void
modifying link
$ rm dangling
$ ln -s empty dangling
$ readlink.py dangling
dangling -> empty
reverting to rev 0:
$ hg revert -r 0 -a
reverting dangling
$ readlink.py dangling
dangling -> nothing
backups:
$ readlink.py *.orig
dangling.orig -> empty
$ rm *.orig
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
copies
$ hg cp -v dangling dangling2
copying dangling to dangling2
$ hg st -Cmard
A dangling2
dangling
$ readlink.py dangling dangling2
dangling -> void
dangling2 -> void
Issue995: hg copy -A incorrectly handles symbolic links
$ hg up -C
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkdir dir
$ ln -s dir dirlink
$ hg ci -qAm 'add dirlink'
$ mkdir newdir
$ mv dir newdir/dir
$ mv dirlink newdir/dirlink
$ hg mv -A dirlink newdir/dirlink
$ cd ..