Deduction regression or improvement?

[Dicebot via Digitalmars-d]

On Friday, 11 March 2016 at 13:28:22 UTC, Hara Kenji wrote:
> On Wednesday, 9 March 2016 at 01:27:41 UTC, Dicebot wrote:
>
> The both cases are disabled in the bugfix PR:
> https://github.com/D-Programming-Language/dmd/pull/4818
>
> I think that T should be deduced to the typeof(true ? cs : ms) 
> at line [a] and typeof(true ? ms : cs) at line [b], then the 
> two lines will get consistent deduction result T == const(S).
>
> Kenji Hara

Sorry, but to me this "fix" looks like harmful regression that 
needs to be reverted. Bug prone or not it breaks valid good code 
without deprecation process.