cmdutil: make amend() take str-keyed opts

I couldn't think of a reasonable change to the signature here, so
unfortunately it keeps the existing one.

Differential Revision: https://phab.mercurial-scm.org/D10862

mercurial/cmdutil.py

@@ -2783,6 +2783,7 b' def samefile(f, ctx1, ctx2):'
 
 
 def amend(ui, repo, old, extra, pats, opts):
+    opts = pycompat.byteskwargs(opts)
     # avoid cycle context -> subrepo -> cmdutil
     from . import context
 

mercurial/commands.py

@@ -2135,8 +2135,8 b' def _docommit(ui, repo, *pats, **opts):'
         if not obsolete.isenabled(repo, obsolete.createmarkersopt):
             cmdutil.checkunfinished(repo)
 
+        node = cmdutil.amend(ui, repo, old, extra, pats, opts)
         opts = pycompat.byteskwargs(opts)
-        node = cmdutil.amend(ui, repo, old, extra, pats, opts)
         if node == old.node():
             ui.status(_(b"nothing changed\n"))
             return 1

tests/test-obsolete.t

@@ -1478,9 +1478,8 b' Test heads computation on pending index '
   > command = registrar.command(cmdtable)
   > @command(b"amendtransient",[], _(b'hg amendtransient [rev]'))
   > def amend(ui, repo, *pats, **opts):
-  >   opts = pycompat.byteskwargs(opts)
-  >   opts[b'message'] = b'Test'
-  >   opts[b'logfile'] = None
+  >   opts['message'] = b'Test'
+  >   opts['logfile'] = None
   >   cmdutil.amend(ui, repo, repo[b'.'], {}, pats, opts)
   >   ui.write(b'%s\n' % stringutil.pprint(repo.changelog.headrevs()))
   > EOF