[FIX] Custom fields required if minLength set and no text typed (#18838)

app/lib/server/functions/validateCustomFields.js

@@ -37,7 +37,7 @@ export const validateCustomFields = function(fields) {
 			throw new Meteor.Error('error-user-registration-custom-field', `Max length of field ${ fieldName } ${ field.maxLength }`, { method: 'registerUser' });
 		}
 
-		if (field.minLength && fieldValue.length < field.minLength) {
+		if (field.minLength && fieldValue.length > 0 && fieldValue.length < field.minLength) {
 			throw new Meteor.Error('error-user-registration-custom-field', `Min length of field ${ fieldName } ${ field.minLength }`, { method: 'registerUser' });
 		}
 	});

client/components/CustomFieldsForm.js

@@ -11,7 +11,7 @@ const CustomTextInput = ({ name, required, minLength, maxLength, setState, state
 	const verify = useMemo(() => {
 		const error = [];
 		if (!state && required) { error.push(t('Field_required')); }
-		if (state.length < minLength) { error.push(t('Min_length_is', minLength)); }
+		if (state.length < minLength && state.length > 0) { error.push(t('Min_length_is', minLength)); }
 		return error.join(', ');
 	}, [state, required, minLength, t]);