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 svn13
$ svnupanddisplay()
> {
> (
> cd $1;
> svn up -q;
> svn st -v | sed 's/ */ /g' | sort
> limit=''
> if [ $2 -gt 0 ]; then
> limit="--limit=$2"
> fi
> svn log --xml -v $limit | python "$TESTDIR/svnxml.py"
> )
> }
$ cat >> $HGRCPATH <<EOF
> [extensions]
> convert =
> EOF
$ hg init a
Add
$ echo a > a/a
$ mkdir -p a/d1/d2
$ echo b > a/d1/d2/b
$ hg --cwd a ci -d '0 0' -A -m 'add a file'
adding a
adding d1/d2/b
Modify
$ svn-safe-append.py a a/a
$ hg --cwd a ci -d '1 0' -m 'modify a file'
$ hg --cwd a tip -q
1:e0e2b8a9156b
$ hg convert -d svn a
assuming destination a-hg
initializing svn repository 'a-hg'
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
1 add a file
0 modify a file
$ svnupanddisplay a-hg-wc 2
2 1 test d1
2 1 test d1/d2 (glob)
2 1 test d1/d2/b (glob)
2 2 test .
2 2 test a
revision: 2
author: test
msg: modify a file
M /a
revision: 1
author: test
msg: add a file
A /a
A /d1
A /d1/d2
A /d1/d2/b
$ ls a a-hg-wc
a:
a
d1
a-hg-wc:
a
d1
$ cmp a/a a-hg-wc/a
Rename
$ hg --cwd a mv a b
$ hg --cwd a ci -d '2 0' -m 'rename a file'
$ hg --cwd a tip -q
2:eb5169441d43
$ hg convert -d svn a
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 rename a file
$ svnupanddisplay a-hg-wc 1
3 1 test d1
3 1 test d1/d2 (glob)
3 1 test d1/d2/b (glob)
3 3 test .
3 3 test b
revision: 3
author: test
msg: rename a file
D /a
A /b (from /a@2)
$ ls a a-hg-wc
a:
b
d1
a-hg-wc:
b
d1
Copy
$ hg --cwd a cp b c
$ hg --cwd a ci -d '3 0' -m 'copy a file'
$ hg --cwd a tip -q
3:60effef6ab48
$ hg convert -d svn a
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 copy a file
$ svnupanddisplay a-hg-wc 1
4 1 test d1
4 1 test d1/d2 (glob)
4 1 test d1/d2/b (glob)
4 3 test b
4 4 test .
4 4 test c
revision: 4
author: test
msg: copy a file
A /c (from /b@3)
$ ls a a-hg-wc
a:
b
c
d1
a-hg-wc:
b
c
d1
$ hg --cwd a rm b
Remove
$ hg --cwd a ci -d '4 0' -m 'remove a file'
$ hg --cwd a tip -q
4:87bbe3013fb6
$ hg convert -d svn a
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 remove a file
$ svnupanddisplay a-hg-wc 1
5 1 test d1
5 1 test d1/d2 (glob)
5 1 test d1/d2/b (glob)
5 4 test c
5 5 test .
revision: 5
author: test
msg: remove a file
D /b
$ ls a a-hg-wc
a:
c
d1
a-hg-wc:
c
d1
Executable
#if execbit
$ chmod +x a/c
#else
$ echo fake >> a/c
#endif
$ hg --cwd a ci -d '5 0' -m 'make a file executable'
#if execbit
$ hg --cwd a tip -q
5:ff42e473c340
#else
$ hg --cwd a tip -q
5:817a700c8cf1
#endif
$ hg convert -d svn a
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 make a file executable
$ svnupanddisplay a-hg-wc 1
6 1 test d1
6 1 test d1/d2 (glob)
6 1 test d1/d2/b (glob)
6 6 test .
6 6 test c
revision: 6
author: test
msg: make a file executable
M /c
#if execbit
$ test -x a-hg-wc/c
#endif
#if symlink
Symlinks
$ ln -s a/missing a/link
$ hg --cwd a commit -Am 'add symlink'
adding link
$ hg --cwd a mv link newlink
$ hg --cwd a commit -m 'move symlink'
$ hg convert -d svn a a-svnlink
initializing svn repository 'a-svnlink'
initializing svn working copy 'a-svnlink-wc'
scanning source...
sorting...
converting...
7 add a file
6 modify a file
5 rename a file
4 copy a file
3 remove a file
2 make a file executable
1 add symlink
0 move symlink
$ svnupanddisplay a-svnlink-wc 1
8 1 test d1
8 1 test d1/d2
8 1 test d1/d2/b
8 6 test c
8 8 test .
8 8 test newlink
revision: 8
author: test
msg: move symlink
D /link
A /newlink (from /link@7)
Make sure our changes don't affect the rest of the test cases
$ hg --cwd a up 5
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg --cwd a --config extensions.strip= strip -r 6
saved backup bundle to $TESTTMP/a/.hg/strip-backup/bd4f7b7a7067-ed505e42-backup.hg (glob)
#endif
Convert with --full adds and removes files that didn't change
$ touch a/f
$ hg -R a ci -Aqmf
$ echo "rename c d" > filemap
$ hg convert -d svn a --filemap filemap --full
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 f
$ svnupanddisplay a-hg-wc 1
7 7 test .
7 7 test d
7 7 test f
revision: 7
author: test
msg: f
D /c
A /d
D /d1
A /f
$ rm -rf a a-hg a-hg-wc
Executable in new directory
$ hg init a
$ mkdir a/d1
$ echo a > a/d1/a
#if execbit
$ chmod +x a/d1/a
#else
$ echo fake >> a/d1/a
#endif
$ hg --cwd a ci -d '0 0' -A -m 'add executable file in new directory'
adding d1/a
$ hg convert -d svn a
assuming destination a-hg
initializing svn repository 'a-hg'
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 add executable file in new directory
$ svnupanddisplay a-hg-wc 1
1 1 test .
1 1 test d1
1 1 test d1/a (glob)
revision: 1
author: test
msg: add executable file in new directory
A /d1
A /d1/a
#if execbit
$ test -x a-hg-wc/d1/a
#endif
Copy to new directory
$ mkdir a/d2
$ hg --cwd a cp d1/a d2/a
$ hg --cwd a ci -d '1 0' -A -m 'copy file to new directory'
$ hg convert -d svn a
assuming destination a-hg
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
0 copy file to new directory
$ svnupanddisplay a-hg-wc 1
2 1 test d1
2 1 test d1/a (glob)
2 2 test .
2 2 test d2
2 2 test d2/a (glob)
revision: 2
author: test
msg: copy file to new directory
A /d2
A /d2/a (from /d1/a@1)
Branchy history
$ hg init b
$ echo base > b/b
$ hg --cwd b ci -d '0 0' -Ambase
adding b
$ svn-safe-append.py left-1 b/b
$ echo left-1 > b/left-1
$ hg --cwd b ci -d '1 0' -Amleft-1
adding left-1
$ svn-safe-append.py left-2 b/b
$ echo left-2 > b/left-2
$ hg --cwd b ci -d '2 0' -Amleft-2
adding left-2
$ hg --cwd b up 0
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ svn-safe-append.py right-1 b/b
$ echo right-1 > b/right-1
$ hg --cwd b ci -d '3 0' -Amright-1
adding right-1
created new head
$ svn-safe-append.py right-2 b/b
$ echo right-2 > b/right-2
$ hg --cwd b ci -d '4 0' -Amright-2
adding right-2
$ hg --cwd b up -C 2
3 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg --cwd b merge
merging b
warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
2 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg --cwd b revert -r 2 b
$ hg --cwd b resolve -m b
(no more unresolved files)
$ hg --cwd b ci -d '5 0' -m 'merge'
Expect 4 changes
$ hg convert -d svn b
assuming destination b-hg
initializing svn repository 'b-hg'
initializing svn working copy 'b-hg-wc'
scanning source...
sorting...
converting...
5 base
4 left-1
3 left-2
2 right-1
1 right-2
0 merge
$ svnupanddisplay b-hg-wc 0
4 2 test left-1
4 3 test b
4 3 test left-2
4 4 test .
4 4 test right-1
4 4 test right-2
revision: 4
author: test
msg: merge
A /right-1
A /right-2
revision: 3
author: test
msg: left-2
M /b
A /left-2
revision: 2
author: test
msg: left-1
M /b
A /left-1
revision: 1
author: test
msg: base
A /b
Tags are not supported, but must not break conversion
$ rm -rf a a-hg a-hg-wc
$ hg init a
$ echo a > a/a
$ hg --cwd a ci -d '0 0' -A -m 'Add file a'
adding a
$ hg --cwd a tag -d '1 0' -m 'Tagged as v1.0' v1.0
$ hg convert -d svn a
assuming destination a-hg
initializing svn repository 'a-hg'
initializing svn working copy 'a-hg-wc'
scanning source...
sorting...
converting...
1 Add file a
0 Tagged as v1.0
writing Subversion tags is not yet implemented
$ svnupanddisplay a-hg-wc 2
2 1 test a
2 2 test .
2 2 test .hgtags
revision: 2
author: test
msg: Tagged as v1.0
A /.hgtags
revision: 1
author: test
msg: Add file a
A /a
$ rm -rf a a-hg a-hg-wc