<form class="comment-create-form" data-ng-submit="submit()">
    <div class="form-error" data-ng-repeat="error in errors">
        <p>{{ error | translate }}</p>
    </div>
    <textarea class="comment-create-form-text" data-msd-elastic="" data-ng-model="data.content"></textarea>
    <footer class="form-footer">
        <input class="comment-create-form-button-submit m-call-to-action form-footer-button-cta" type="submit" value="{{ 'TR__CREATE' | translate }}" />
        <a href="" class="button form-footer-button" data-ng-click="cancel()" data-ng-if="!hideCancel">{{ "TR__CANCEL" | translate }}</a>
    </footer>
</form>

<form class="comment-create-form" data-ng-submit="submit()">
    <div class="form-error" data-ng-repeat="error in errors">
        <p>{{ error | translate }}</p>
    </div>
    <textarea class="comment-create-form-text" data-msd-elastic="" data-ng-model="data.content"></textarea>
    <footer class="form-footer">
        <input class="comment-create-form-button-submit m-call-to-action form-footer-button-cta"
            type="submit"
            value="{{ 'TR__CREATE' | translate }}"
            data-ng-disabled="!data.content" />
        <a href="" class="button form-footer-button" data-ng-click="cancel()" data-ng-if="!hideCancel">{{ "TR__CANCEL" | translate }}</a>
    </footer>
</form>

Disable comment submit button as long as text is empty
Disable comment submit button as long as text is empty
