Sass compiler ignores parent selector if not followed by certain chars.

[vaadin-bot]

Originally by szebelledimark

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According to Sass reference, the following code:

.v-button {
    ...

    &:after {
        ...
    }

    &-icon-only {
        ...
    }
}

should compiled into:

.v-button {
    ...
}
.v-button:after {
    ...
}   
.v-button-icon-only {
    ...
}

instead it complies to:

.v-button {
    ...
}
.v-button:after {
    ...
}

It ignores the block if the parent selector is not followed by ":", " ", ">".

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Imported from https://dev.vaadin.com/ issue #17053