I will not reopen this now for the reasons I already stated after "In any case ...". To expand on that.

1. 2.7 is in maintenance (bug-fix only) mode and I view this a feature request. To persuade someone otherwise, quote some doc that clearly says subprocess should behave as requested. I nosy-ed Jesse Noller so he can contradict me if he wishes.

2. The underlying issue seems to be the use of limited encodings, which was and is being fixed as well as possible in 3.x. Since there has been no mention of this issue being a problem with subprocess in 3.1, I presume there is none. If there is, say so and I will reopen.

The discussion shows disagreement on both the goal and approach to change. I am dubious that there will be an acceptable general solution. Even if this is persuasively seen as a bug and there is a good patch, I am dubious that any of the current developers will want to spent the necessary time to properly review a workaround to an issue that was already fixed the right way in 3.x.