Ran into this problem earlier. For a multi return value function
fn=function() return 'a','b' end
the call
print(fn()) returns a b
but the call
print(fn() or nil) returns only a
why? or should not matter since the first call was successful right?
Quoting from Programming in Lua §5.1 – Multiple Results
Lua always adjusts the number of results from a function to the circumstances of the call. When we call a function as a statement, Lua discards all results from the function. When we use a call as an expression, Lua keeps only the first result. We get all results only when the call is the last (or the only) expression in a list of expressions.
In the case of your example, the return value of fn() is used as an expression (the left operand of or operator), so only the first value is kept.
