[dev.fuzz] all: merge master into dev.fuzz

Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2

1 files changed, 23 insertions, 24 deletions

diff --git a/src/os/error.go b/src/os/error.go
index 875cc9711f..704a6fb29e 100644
--- a/src/os/error.go
+++ b/src/os/error.go
@@ -7,6 +7,7 @@ package os
 import (
 	"internal/oserror"
 	"internal/poll"
+	"io/fs"
 )
 
 // Portable analogs of some common system call errors.
@@ -16,20 +17,17 @@ import (
 var (
 	// ErrInvalid indicates an invalid argument.
 	// Methods on File will return this error when the receiver is nil.
-	ErrInvalid = errInvalid() // "invalid argument"
+	ErrInvalid = fs.ErrInvalid // "invalid argument"
+
+	ErrPermission = fs.ErrPermission // "permission denied"
+	ErrExist      = fs.ErrExist      // "file already exists"
+	ErrNotExist   = fs.ErrNotExist   // "file does not exist"
+	ErrClosed     = fs.ErrClosed     // "file already closed"
 
-	ErrPermission       = errPermission()       // "permission denied"
-	ErrExist            = errExist()            // "file already exists"
-	ErrNotExist         = errNotExist()         // "file does not exist"
-	ErrClosed           = errClosed()           // "file already closed"
 	ErrNoDeadline       = errNoDeadline()       // "file type does not support deadline"
 	ErrDeadlineExceeded = errDeadlineExceeded() // "i/o timeout"
 )
 
-func errInvalid() error    { return oserror.ErrInvalid }
-func errPermission() error { return oserror.ErrPermission }
-func errExist() error      { return oserror.ErrExist }
-func errNotExist() error   { return oserror.ErrNotExist }
 func errClosed() error     { return oserror.ErrClosed }
 func errNoDeadline() error { return poll.ErrNoDeadline }
 
@@ -47,21 +45,7 @@ type timeout interface {
 }
 
 // PathError records an error and the operation and file path that caused it.
-type PathError struct {
-	Op   string
-	Path string
-	Err  error
-}
-
-func (e *PathError) Error() string { return e.Op + " " + e.Path + ": " + e.Err.Error() }
-
-func (e *PathError) Unwrap() error { return e.Err }
-
-// Timeout reports whether this error represents a timeout.
-func (e *PathError) Timeout() bool {
-	t, ok := e.Err.(timeout)
-	return ok && t.Timeout()
-}
+type PathError = fs.PathError
 
 // SyscallError records an error from a specific system call.
 type SyscallError struct {
@@ -92,6 +76,9 @@ func NewSyscallError(syscall string, err error) error {
 // IsExist returns a boolean indicating whether the error is known to report
 // that a file or directory already exists. It is satisfied by ErrExist as
 // well as some syscall errors.
+//
+// This function predates errors.Is. It only supports errors returned by
+// the os package. New code should use errors.Is(err, os.ErrExist).
 func IsExist(err error) bool {
 	return underlyingErrorIs(err, ErrExist)
 }
@@ -99,6 +86,9 @@ func IsExist(err error) bool {
 // IsNotExist returns a boolean indicating whether the error is known to
 // report that a file or directory does not exist. It is satisfied by
 // ErrNotExist as well as some syscall errors.
+//
+// This function predates errors.Is. It only supports errors returned by
+// the os package. New code should use errors.Is(err, os.ErrNotExist).
 func IsNotExist(err error) bool {
 	return underlyingErrorIs(err, ErrNotExist)
 }
@@ -106,12 +96,21 @@ func IsNotExist(err error) bool {
 // IsPermission returns a boolean indicating whether the error is known to
 // report that permission is denied. It is satisfied by ErrPermission as well
 // as some syscall errors.
+//
+// This function predates errors.Is. It only supports errors returned by
+// the os package. New code should use errors.Is(err, os.ErrPermission).
 func IsPermission(err error) bool {
 	return underlyingErrorIs(err, ErrPermission)
 }
 
 // IsTimeout returns a boolean indicating whether the error is known
 // to report that a timeout occurred.
+//
+// This function predates errors.Is, and the notion of whether an
+// error indicates a timeout can be ambiguous. For example, the Unix
+// error EWOULDBLOCK sometimes indicates a timeout and sometimes does not.
+// New code should use errors.Is with a value appropriate to the call
+// returning the error, such as os.ErrDeadlineExceeded.
 func IsTimeout(err error) bool {
 	terr, ok := underlyingError(err).(timeout)
 	return ok && terr.Timeout()