Runtime implementation of built-in operator "isset" does not support OR operator

[hannesscharmann-tomtom]

Zserio version and language
Zserio: 2.14.0
Language: C++/Java/Python

Describe the bug
The implemenation of BuiltInOperators.isSet(ZserioBitmask a, ZserioBitmask b) always assumes that all bits of b must be set in a (i.e. AND combines the two values). Zserio language specification however, allows the usage of AND, OR, and also a combination of both operators. This is why a condition like if isset(content, MyBitMask.A | MyBitMask.B) (with bitmask varuint32 MyBitMask) only evaluates to true if both bits are set.

How to reproduce
Steps to reproduce the behavior:

• Example schema

bitmask varuint32 MyBitMask
{
    A,
    B
};

struct MyStruct
{
    MyBitMask content;
    string myOptionalField if isset(content, MyBitMask.A | MyBitMask.B);
};

• Sample code (*.cpp / *.java / *.py)

public boolean isMyOptionalFieldUsed()
{
    return (zserio.runtime.BuiltInOperators.isSet(getContent(), MyBitMask.Values.A.or(MyBitMask.Values.B)));
}

• Error
  isMyOptionalFieldUsed() returns false when only one of the two bits (A OR B) is set in bitmask content.

Expected behavior
The implementation of the isset operator shall support OR operators and also combinations of AND and OR operators.

Additional context
n/a

[mikir]

Operator isset is implemented as defined.