math/big: fix typo in documentation for Int.Exp

Fixes #38304

Also change `If m > 0, y < 0, ...` to `If m != 0, y < 0, ...` since `Exp` will return `nil`
whatever `m`'s sign is.

Change-Id: I17d7337ccd1404318cea5d42a8de904ad185fd00
GitHub-Last-Rev: 23995103000505dbf35aa29a717470c4da638fda
GitHub-Pull-Request: golang/go#38390
Reviewed-on: https://go-review.googlesource.com/c/go/+/228000
Reviewed-by: Robert Griesemer <gri@golang.org>

diff --git a/src/math/big/int.go b/src/math/big/int.go
index 18f122e953c45a5b314d95d6fff564db02d18fe4..8816cf5266cc4f9eab65efb89ef1ed8f01d24d5c 100644 (file)
--- a/src/math/big/int.go
+++ b/src/math/big/int.go
@@ -465,8 +465,8 @@ func (x *Int) TrailingZeroBits() uint {
 }
 
 // Exp sets z = x**y mod |m| (i.e. the sign of m is ignored), and returns z.
-// If m == nil or m == 0, z = x**y unless y <= 0 then z = 1. If m > 0, y < 0,
-// and x and n are not relatively prime, z is unchanged and nil is returned.
+// If m == nil or m == 0, z = x**y unless y <= 0 then z = 1. If m != 0, y < 0,
+// and x and m are not relatively prime, z is unchanged and nil is returned.
 //
 // Modular exponentiation of inputs of a particular size is not a
 // cryptographically constant-time operation.