NPE in a setter method for a length-restricted string.

The following patch changed behavior of builder class generated by yangtools.

commit 7998081d8e1761bf4798c1642e8e6107fc4666fc
Author: Robert Varga <rovarga@cisco.com>
Date: Sun May 31 19:51:43 2015 +0200

BUG-1485: convert BuilderTemplate to use LengthGenerator

Before that patch was merged, a setter method for a length-restricted string accepts a null string.

YANG model:
container test {
leaf name {
type string

{ length "1 .. 31"; }

}
}

Setter method in a builder class:
public TestBuilder setName(java.lang.String value) {
if (value != null) {
BigInteger _constraint = BigInteger.valueOf(value.length());
boolean isValidLength = false;
for (Range<BigInteger> r : _name_length()) {
if (r.contains(_constraint))

{ isValidLength = true; }

}
if (!isValidLength)

{ throw new IllegalArgumentException(String.format("Invalid length: %s, expected: %s.", value, _name_length)); }

}
this._name = value;
return this;
}

But after that patch was merged, a setter method for a length-restricted string causes NPE when a null string is passed.

private static void check_nameLength(final String value) {
final int length = value.length(); <=== NPE if value is null
if (length >= 1 && length <= 31)

{ return; }

throw new IllegalArgumentException(String.format("Invalid length: %s, expected: [[1‥31]].", value));
}

public TestBuilder setName(java.lang.String value)

{ check_nameLength(value); this._name = value; return this; }

I think a setter method should accept a null string even if a length restriction is applied.