It took me awhile to re-recognize Это из консоли: as 'made in konsole'.
I agree that the discrepancy between Idle shell and console is a bug relative to a general goal of having them work as nearly the same as possible and sensible.

> This bug is critical for non-ASCII-only users of IDLE.

This bug, like many others involving non-Ascii chars, has already been fixed in 3.x, though it is not only a 2 versus 3 issue. Given that there are technical limits to imitating the console, we could have closed this issue as already fixed, "wont fix" in 2.7, upgrade to a version that has the fix.  However, since this is also a within 2.7, console versus Idle issue, improvement would be good.

The +coding cookie, -1 line hack induces a non-obvious dependency between files that I think should be documented by comments such as
# run.cleanup_traceback() compensates for added line
# compensation for coding cookie added in pyshel..runsource()

I think it ok to push less than perfect patches that make definite improvements and do not preclude possibly better patches in the future.  I have not seen any comment from alex whether this fixes his particular example on his machine, but if you are convinced that this fixes some problems and only causes a micro slowdown of working uses, go ahead.