Cary Huang <cary(dot)huang(at)highgo(dot)ca> writes:
> I noticed that when casting a string to boolean value with input 'of' it still cast it to 'f'. I think with 'of', it should give an error because 'off' is the expected candidate. This may not be intended so I made a simple patch to address this.
It's absolutely intended, and documented:
https://www.postgresql.org/docs/devel/datatype-boolean.html
Note the bit about "Unique prefixes of these strings are also accepted".
The code comment just above parse_bool() says the same.
regards, tom lane