## Context
avatarUrl is a TEXT field type so non nullable, which means if we try to
run a mutation with null it will either fail or be ignored. Here this is
the second option, done in sanitizeRecordInput where when a
fieldMetadata has isNullable=false and the value is null, we return
undefined. This caused the mutation to send an empty input and not
remove the avatar
Weiko
5d0ec9116f