[css-align] 'width: auto' turning into 'fit-content' isn't compatible with existing behavior #1437
Description
As @MatsPalmgren points out on Bugzilla, the sentence at the end of the definition of justify-self:
Values other than stretch cause a width/height of auto to be treated as fit-content.
combined with the rules for justify-self on blocks mean that the spec makes the default behavior for blocks to be fit-content sizing rather than stretch sizing, which is not compatible with the existing behavior of blocks in the normal flow.