graft: assign computed configuration value to statedata instead of opts

The goal is for the graft logic to not deal with the command line option, so
lets to reinjecting value in these config option.

mercurial/cmd_impls/graft.py

@@ -96,12 +96,6 def _process_args(ui, repo, *revs, **opt
         # read in unfinished revisions
         if graftstate.exists():
             statedata = cmdutil.readgraftstate(repo, graftstate)
-            if statedata.get(b'date'):
-                opts['date'] = statedata[b'date']
-            if statedata.get(b'user'):
-                opts['user'] = statedata[b'user']
-            if statedata.get(b'log'):
-                opts['log'] = True
             if statedata.get(b'no_commit'):
                 opts['no_commit'] = statedata.get(b'no_commit')
             if statedata.get(b'base'):
@@ -117,6 +111,17 def _process_args(ui, repo, *revs, **opt
         cmdutil.bailifchanged(repo)
         revs = logcmdutil.revrange(repo, revs)
 
+    for o in (
+        b'date',
+        b'user',
+        b'log',
+    ):
+        v = opts.get(o.decode('ascii'))
+        # if statedata is already set, it comes from --continue and test says
+        # we should honor them above the options (which seems weird).
+        if v and o not in statedata:
+            statedata[o] = v
+
     skipped = set()
     basectx = None
     if opts.get('base'):
@@ -251,18 +256,11 def _graft_revisions(
             extra[b'intermediate-source'] = ctx.hex()
         else:
             extra[b'source'] = ctx.hex()
-        user = ctx.user()
-        if opts.get('user'):
-            user = opts['user']
-            statedata[b'user'] = user
-        date = ctx.date()
-        if opts.get('date'):
-            date = opts['date']
-            statedata[b'date'] = date
+        user = statedata.get(b'user', ctx.user())
+        date = statedata.get(b'date', ctx.date())
         message = ctx.description()
-        if opts.get('log'):
+        if statedata.get(b'log'):
             message += b'\n(grafted from %s)' % ctx.hex()
-            statedata[b'log'] = True
 
         # we don't merge the first commit when continuing
         if not cont: