Correct procedure when working on bugs tracked in bugzilla?

Hi R-core,

I have been working on squashing a few bugs in the past couple of days
(specifically I have submitted patches for
15425<https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=15425>and
15253 <https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=15253>) , but I
haven't been assigning the bugs to myself in bugzilla as I was not sure if
that is something only R-core members should be doing.

Is there a correct/desired way that I as a non-R-core member should
indicate that I'm working on a fix for a particular bug or am interested
in/willing to do so?

As far as I am aware there is no official policy on this, so I'll give 
an opinion:

Assigning it to yourself would probably be bad: I wouldn't even look at 
it any more.  I don't know policies of other Core members.

The best approach is to add a note on the bug saying you're working on 
it (which will push it to the top of the list in the default ordering), 
along with a note saying when you expect to be done.  That would stop me 
from spending time on it until you submitted a patch, or your stated 
deadline was long past.

Duncan Murdoch