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 that a commit clears the merge state.
$ hg init repo
$ cd repo
$ echo foo > file1
$ echo foo > file2
$ hg commit -Am 'add files'
adding file1
adding file2
$ echo bar >> file1
$ echo bar >> file2
$ hg commit -Am 'append bar to files'
create a second head with conflicting edits
$ hg up -C 0
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo baz >> file1
$ echo baz >> file2
$ hg commit -Am 'append baz to files'
created new head
create a third head with no conflicting edits
$ hg up -qC 0
$ echo foo > file3
$ hg commit -Am 'add non-conflicting file'
adding file3
created new head
failing merge
$ hg up -qC 2
$ hg merge --tool=internal:fail 1
0 files updated, 0 files merged, 0 files removed, 2 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
resolve -l should contain unresolved entries
$ hg resolve -l
U file1
U file2
$ hg resolve -l --no-status
file1
file2
resolving an unknown path should emit a warning, but not for -l
$ hg resolve -m does-not-exist
arguments do not match paths that need resolving
$ hg resolve -l does-not-exist
don't allow marking or unmarking driver-resolved files
$ cat > $TESTTMP/markdriver.py << EOF
> '''mark and unmark files as driver-resolved'''
> from mercurial import cmdutil, merge, scmutil
> cmdtable = {}
> command = cmdutil.command(cmdtable)
> @command('markdriver',
> [('u', 'unmark', None, '')],
> 'FILE...')
> def markdriver(ui, repo, *pats, **opts):
> wlock = repo.wlock()
> try:
> ms = merge.mergestate.read(repo)
> m = scmutil.match(repo[None], pats, opts)
> for f in ms:
> if not m(f):
> continue
> if not opts['unmark']:
> ms.mark(f, 'd')
> else:
> ms.mark(f, 'u')
> ms.commit()
> finally:
> wlock.release()
> EOF
$ hg --config extensions.markdriver=$TESTTMP/markdriver.py markdriver file1
$ hg resolve --list
D file1
U file2
$ hg resolve --mark file1
not marking file1 as it is driver-resolved
this should not print out file1
$ hg resolve --mark --all
(no more unresolved files -- run "hg resolve --all" to conclude)
$ hg resolve --mark 'glob:file*'
(no more unresolved files -- run "hg resolve --all" to conclude)
$ hg resolve --list
D file1
R file2
$ hg resolve --unmark file1
not unmarking file1 as it is driver-resolved
(no more unresolved files -- run "hg resolve --all" to conclude)
$ hg resolve --unmark --all
$ hg resolve --list
D file1
U file2
$ hg --config extensions.markdriver=$TESTTMP/markdriver.py markdriver --unmark file1
$ hg resolve --list
U file1
U file2
resolve the failure
$ echo resolved > file1
$ hg resolve -m file1
resolve -l should show resolved file as resolved
$ hg resolve -l
R file1
U file2
$ hg resolve -l -Tjson
[
{
"path": "file1",
"status": "R"
},
{
"path": "file2",
"status": "U"
}
]
resolve -m without paths should mark all resolved
$ hg resolve -m
(no more unresolved files)
$ hg commit -m 'resolved'
resolve -l should be empty after commit
$ hg resolve -l
$ hg resolve -l -Tjson
[
]
resolve --all should abort when no merge in progress
$ hg resolve --all
abort: resolve command not applicable when not merging
[255]
resolve -m should abort when no merge in progress
$ hg resolve -m
abort: resolve command not applicable when not merging
[255]
set up conflict-free merge
$ hg up -qC 3
$ hg merge 1
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
resolve --all should do nothing in merge without conflicts
$ hg resolve --all
(no more unresolved files)
resolve -m should do nothing in merge without conflicts
$ hg resolve -m
(no more unresolved files)
get back to conflicting state
$ hg up -qC 2
$ hg merge --tool=internal:fail 1
0 files updated, 0 files merged, 0 files removed, 2 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
resolve without arguments should suggest --all
$ hg resolve
abort: no files or directories specified
(use --all to re-merge all unresolved files)
[255]
resolve --all should re-merge all unresolved files
$ hg resolve --all
merging file1
merging file2
warning: conflicts while merging file1! (edit, then use 'hg resolve --mark')
warning: conflicts while merging file2! (edit, then use 'hg resolve --mark')
[1]
$ cat file1.orig
foo
baz
$ cat file2.orig
foo
baz
.orig files should exists where specified
$ hg resolve --all --verbose --config 'ui.origbackuppath=.hg/origbackups'
merging file1
creating directory: $TESTTMP/repo/.hg/origbackups (glob)
merging file2
warning: conflicts while merging file1! (edit, then use 'hg resolve --mark')
warning: conflicts while merging file2! (edit, then use 'hg resolve --mark')
[1]
$ ls .hg/origbackups
file1.orig
file2.orig
$ grep '<<<' file1 > /dev/null
$ grep '<<<' file2 > /dev/null
resolve <file> should re-merge file
$ echo resolved > file1
$ hg resolve -q file1
warning: conflicts while merging file1! (edit, then use 'hg resolve --mark')
[1]
$ grep '<<<' file1 > /dev/null
test .orig behavior with resolve
$ hg resolve -q file1 --tool "sh -c 'f --dump \"$TESTTMP/repo/file1.orig\"'"
$TESTTMP/repo/file1.orig: (glob)
>>>
foo
baz
<<<
resolve <file> should do nothing if 'file' was marked resolved
$ echo resolved > file1
$ hg resolve -m file1
$ hg resolve -q file1
$ cat file1
resolved
insert unsupported advisory merge record
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -x
$ hg debugmergestate
* version 2 records
local: 57653b9f834a4493f7240b0681efcb9ae7cab745
other: dc77451844e37f03f5c559e3b8529b2b48d381d1
unrecognized entry: x advisory record
file: file1 (record type "F", state "r", hash 60b27f004e454aca81b0480209cce5081ec52390)
local path: file1 (flags "")
ancestor path: file1 (node 2ed2a3912a0b24502043eae84ee4b279c18b90dd)
other path: file1 (node 6f4310b00b9a147241b071a60c28a650827fb03d)
file: file2 (record type "F", state "u", hash cb99b709a1978bd205ab9dfd4c5aaa1fc91c7523)
local path: file2 (flags "")
ancestor path: file2 (node 2ed2a3912a0b24502043eae84ee4b279c18b90dd)
other path: file2 (node 6f4310b00b9a147241b071a60c28a650827fb03d)
$ hg resolve -l
R file1
U file2
insert unsupported mandatory merge record
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -X
$ hg debugmergestate
* version 2 records
local: 57653b9f834a4493f7240b0681efcb9ae7cab745
other: dc77451844e37f03f5c559e3b8529b2b48d381d1
file: file1 (record type "F", state "r", hash 60b27f004e454aca81b0480209cce5081ec52390)
local path: file1 (flags "")
ancestor path: file1 (node 2ed2a3912a0b24502043eae84ee4b279c18b90dd)
other path: file1 (node 6f4310b00b9a147241b071a60c28a650827fb03d)
file: file2 (record type "F", state "u", hash cb99b709a1978bd205ab9dfd4c5aaa1fc91c7523)
local path: file2 (flags "")
ancestor path: file2 (node 2ed2a3912a0b24502043eae84ee4b279c18b90dd)
other path: file2 (node 6f4310b00b9a147241b071a60c28a650827fb03d)
unrecognized entry: X mandatory record
$ hg resolve -l
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg resolve -ma
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg summary
parent: 2:57653b9f834a
append baz to files
parent: 1:dc77451844e3
append bar to files
branch: default
warning: merge state has unsupported record types: X
commit: 2 modified, 2 unknown (merge)
update: 2 new changesets (update)
phases: 5 draft
update --clean shouldn't abort on unsupported records
$ hg up -qC 1
$ hg debugmergestate
no merge state found
test crashed merge with empty mergestate
$ mkdir .hg/merge
$ touch .hg/merge/state
resolve -l should be empty
$ hg resolve -l
$ cd ..