isConstructorType checks base constraint for undefined#14250
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Previously, it assumed there was always a base constraint, which is true for correct code. For incorrect code, the base constraint may be missing, which caused a crash because the base constraint was undefined.
mhegazy
approved these changes
Feb 22, 2017
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Previously,
isConstructorTypeassumed there was always a base constraint for all type variables. When the base constraint it missing, it caused a crash because the base constraint was undefined.isConstructorTypeusesgetBaseConstraintOfTypeto get the constraint on the type variable. All other callers togetBaseConstraintOfTypecheck for undefined before using the constraint, so the fix is to check for undefined here too.Fixes #14238