Python indentation too deep when expression before colon is multi-line

[krassowski]

Describe the issue

When the expression in if, def or other block is spanning multiple lines the indent is too deep. It should be one level of indentation (for Python usually 4 spaces or tab) but it is as many spces as to match the position of the colon:

def test(x,
         y): # press enter here, see indent is too deep (fail!)

or

if (x
    and y): # press enter here, see indent is too deep (fail!)

This does not happen (i.e. works as expected) for single-line statments:

def test(x, y): # press enter here, see indent is one level deep (ok)

Browser and platform

Edge and Firefox

Reproduction link

https://codemirror.net/try/?c=aW1wb3J0IHtiYXNpY1NldHVwLCBFZGl0b3JWaWV3fSBmcm9tICJjb2RlbWlycm9yIgppbXBvcnQge3B5dGhvbn0gZnJvbSAiQGNvZGVtaXJyb3IvbGFuZy1weXRob24iCgpuZXcgRWRpdG9yVmlldyh7CiAgZG9jOiAiZGVmIHRlc3QoeCxcbiAgICAgICAgIHkpOiAjIHByZXNzIGVudGVyIGhlcmUsIHNlZSBpbmRlbnQgdG9vIGRlZXAgKHNob3VsZCBiZSA0IHNwYWNlcyBidXQgaXMgMTEpXG4iLAogIGV4dGVuc2lvbnM6IFtiYXNpY1NldHVwLCBweXRob24oKV0sCiAgcGFyZW50OiBkb2N1bWVudC5ib2R5Cn0pCg==

[mbakker7]

Same error in Safari and Chrome on Mac.

[marijnh]

Attached patch should address this.