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tsc TypeError: Cannot read property 'flags' of undefined #16861

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@koloboid

Description

@koloboid

TypeScript Version: 2.4.1

Code

// This is minimal chunk of code
class BaseType<T> {
    bar: T
}

class NextType<C extends { someProp: any }, T = C['someProp']> extends BaseType<T> {
}

class Foo extends NextType<Foo> {
    someProp: {
        test: true
    }
}

const foo = new Foo();
foo.bar.test

Expected behavior:
Just to compile and run. May be this code violates TypeScript rules, but the actual result is unexpected, anyway
Both atom-typescript and WebStorm EAP consider this code as valid, and even correctly auto-complete "foo.bar.test"

Actual behavior:

$ tsc
/usr/lib/node_modules/typescript/lib/tsc.js:55776
                throw e;
                ^

TypeError: Cannot read property 'flags' of undefined
    at Object.getCheckFlags (/usr/lib/node_modules/typescript/lib/tsc.js:7996:22)
    at getTargetSymbol (/usr/lib/node_modules/typescript/lib/tsc.js:37957:23)
    at checkKindsOfPropertyMemberOverrides (/usr/lib/node_modules/typescript/lib/tsc.js:37975:31)
    at checkClassLikeDeclaration (/usr/lib/node_modules/typescript/lib/tsc.js:37915:21)
    at checkClassDeclaration (/usr/lib/node_modules/typescript/lib/tsc.js:37858:13)
    at checkSourceElement (/usr/lib/node_modules/typescript/lib/tsc.js:38767:28)
    at Object.forEach (/usr/lib/node_modules/typescript/lib/tsc.js:298:30)
    at checkSourceFileWorker (/usr/lib/node_modules/typescript/lib/tsc.js:38836:20)
    at checkSourceFile (/usr/lib/node_modules/typescript/lib/tsc.js:38821:13)
    at getDiagnosticsWorker (/usr/lib/node_modules/typescript/lib/tsc.js:38874:17)

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