Cannot parse dict comprehension with negative number

[vaer-k]

Operating system: MacOS 10.12.6
Python version: 3.6
Black version: 18.3a3
Does also happen on master: yes

{a: b * -2 for a, b in dictionary.items()}
becomes
{a: b * -2for a, b in dictionary.items()}

which, surprisingly to me, doesn't break, but is clearly wrong.

{a: b * 2 for a, b in dictionary.items()}
is not affected by this issue (black leaves it alone.)

[ambv]

Thanks for your report! This is now fixed. ✨ 🍰 ✨