tests: pass parent revision as integer to repo[x] in test-context-metadata.t

Support for looking up by stringified int is going away. It's already
deprecated, but I think I didn't notice this case because the test
case pipes through `grep`.

Differential Revision: https://phab.mercurial-scm.org/D3448

tests/test-context-metadata.t

@@ -1,51 +1,51
 Tests about metadataonlyctx
 
   $ hg init
   $ echo A > A
   $ hg commit -A A -m 'Add A'
   $ echo B > B
   $ hg commit -A B -m 'Add B'
   $ hg rm A
   $ echo C > C
   $ echo B2 > B
   $ hg add C -q
   $ hg commit -m 'Remove A'
 
   $ cat > metaedit.py <<EOF
   > from __future__ import absolute_import
   > from mercurial import context, pycompat, registrar
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > @command(b'metaedit')
   > def metaedit(ui, repo, arg):
   >     # Modify commit message to "FOO"
   >     with repo.wlock(), repo.lock(), repo.transaction(b'metaedit'):
   >         old = repo[b'.']
   >         kwargs = dict(s.split(b'=', 1) for s in arg.split(b';'))
   >         if 'parents' in kwargs:
-  >             kwargs[b'parents'] = kwargs[b'parents'].split(b',')
+  >             kwargs[b'parents'] = map(int, kwargs[b'parents'].split(b','))
   >         new = context.metadataonlyctx(repo, old,
   >                                       **pycompat.strkwargs(kwargs))
   >         new.commit()
   > EOF
   $ hg --config extensions.metaedit=$TESTTMP/metaedit.py metaedit 'text=Changed'
   $ hg log -r tip
   changeset:   3:ad83e9e00ec9
   tag:         tip
   parent:      1:3afb7afe6632
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Changed
   
   $ hg --config extensions.metaedit=$TESTTMP/metaedit.py metaedit 'parents=0' 2>&1 | egrep '^RuntimeError'
   RuntimeError: can't reuse the manifest: its p1 doesn't match the new ctx p1
 
   $ hg --config extensions.metaedit=$TESTTMP/metaedit.py metaedit 'user=foo <[e-mail]>'
   $ hg log -r tip
   changeset:   4:1f86eaeca92b
   tag:         tip
   parent:      1:3afb7afe6632
   user:        foo <[e-mail]>
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Remove A