cmdutil: make checknotesize() work on str-keyed opts

Since this patch changes the behavior of the function, I consider it a
bonus if the signature also changes so that extensions can detect
which version they're dealing with (for the record, I don't have any
such extensions). Therefore, I also dropped an unused `ui` argument
and renamed the function to use snake_case.

Differential Revision: https://phab.mercurial-scm.org/D10859

hgext/amend.py

@@ -16,7 +16,6 from mercurial.i18n import _
 from mercurial import (
     cmdutil,
     commands,
-    pycompat,
     registrar,
 )
 
@@ -66,7 +65,7 def amend(ui, repo, *pats, **opts):
 
     See :hg:`help commit` for more details.
     """
-    cmdutil.checknotesize(ui, pycompat.byteskwargs(opts))
+    cmdutil.check_note_size(opts)
 
     with repo.wlock(), repo.lock():
         if not opts.get('logfile'):

hgext/uncommit.py

@@ -153,9 +153,8 def uncommit(ui, repo, *pats, **opts):
     If no files are specified, the commit will be pruned, unless --keep is
     given.
     """
+    cmdutil.check_note_size(opts)
     opts = pycompat.byteskwargs(opts)
-
-    cmdutil.checknotesize(ui, opts)
     cmdutil.resolvecommitoptions(ui, opts)
 
     with repo.wlock(), repo.lock():

mercurial/cmdutil.py

@@ -328,10 +328,10 def resolvecommitoptions(ui, opts):
     return datemaydiffer
 
 
-def checknotesize(ui, opts):
+def check_note_size(opts):
     """make sure note is of valid format"""
 
-    note = opts.get(b'note')
+    note = opts.get('note')
     if not note:
         return