os: document that behavior of Seek on O_APPEND files is not specified
The actual behavior varies across platforms, and due to the inherent
race, we can't do anything better (other than to always return 0).
Fixes #12710.
Change-Id: Icb52f0f1f0a267e0f9f70767cae427f3f0239965
Reviewed-on: https://go-review.googlesource.com/14881
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/os/file.go b/src/os/file.go
index 69338ce..a662197 100644
--- a/src/os/file.go
+++ b/src/os/file.go
@@ -173,6 +173,7 @@
// according to whence: 0 means relative to the origin of the file, 1 means
// relative to the current offset, and 2 means relative to the end.
// It returns the new offset and an error, if any.
+// The behavior of Seek on a file opened with O_APPEND is not specified.
func (f *File) Seek(offset int64, whence int) (ret int64, err error) {
if f == nil {
return 0, ErrInvalid
