node-history: small fixes and added a investigation note

vcsserver/remote/hg_remote.py

@@ -567,14 +567,16 b' class HgRemote(RemoteBase):'
 
             def history_iter():
                 limit_rev = fctx.rev()
-                for obj in reversed(list(fctx.filelog())):
-                    obj = fctx.filectx(obj)
-                    ctx = obj.changectx()
-                    if ctx.hidden() or ctx.obsolete():
+                for fctx_candidate in reversed(list(fctx.filelog())):
+                    f_obj = fctx.filectx(fctx_candidate)
+
+                    # NOTE: This can be problematic...we can hide ONLY history node resulting in empty history
+                    _ctx = obj.changectx()
+                    if _ctx.hidden() or _ctx.obsolete():
                         continue
 
-                    if limit_rev >= obj.rev():
-                        yield obj
+                    if limit_rev >= f_obj.rev():
+                        yield f_obj
 
             history = []
             for cnt, obj in enumerate(history_iter()):
@@ -586,7 +588,7 b' class HgRemote(RemoteBase):'
         return _node_history(context_uid, repo_id, revision, path, limit)
 
     @reraise_safe_exceptions
-    def node_history_untill(self, wire, revision, path, limit):
+    def node_history_until(self, wire, revision, path, limit):
         cache_on, context_uid, repo_id = self._cache_on(wire)
         region = self._region(wire)