Is correct but incomplete documentation considered a bug? The documentation of trigonometric functions goes into detail about branch cuts for asin etc., but does not discuss the discontinuities of atan2. (It also fails to explain the difference between asin(2) (NaN) and asin(2+0i) (pi/2-acosh(2)i).) Since atan2 accepts complex arguments, the discontinuities are not just on the half-axis with x<=0 and y=0.
I also think that documentation of trigonometric functions should link to hyperbolic functions and that documentation of hyperbolic functions should link to the exponential function.