[Python-Dev] when to fix cross-version bugs?

[R. David Murray]

On Fri, 06 Sep 2013 07:51:06 -0700, Ethan Furman <ethan at stoneleaf.us> wrote:
> I recently committed a fix for unicodeobject.c so that the %d, %i, and %u format specifiers always output values 
> (otherwise, in subclasses, the str() was used instead).
>
> Should this be fixed in 3.3 as well?
> 
> What guidelines determine when a bug is fixed in previous versions?

The basic guideline is: we try very hard not to break currently working
code in a maintenance release.  Making that decision very much depends on
the details of each individual case.

I'd say this one is borderline...it would probably be OK to backport it,
since programs depending on the str of number subclasses (that is what
we are talking about here, right?  Even though you say the fix is in
unicodeobject.c...) are likely to be rare, or already have a workaround
that won't get broken by the change, but by the same token it probably
doesn't have much positive impact if it does get backported, so is it
worth the (small) chance of breaking someone's code?

--David