syscall: remove dependency on io

Keep syscall and io separated; neither should depend on the other.

Change-Id: Icdd61bd0c05d874cabd7b5ae6631dd09dec90112
Reviewed-on: https://go-review.googlesource.com/c/go/+/243902
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

3 files changed, 6 insertions, 30 deletions

diff --git a/src/internal/syscall/windows/registry/key.go b/src/internal/syscall/windows/registry/key.go
index cc3d0c774b..612c48f084 100644
--- a/src/internal/syscall/windows/registry/key.go
+++ b/src/internal/syscall/windows/registry/key.go
@@ -25,10 +25,7 @@
 //
 package registry
 
-import (
-	"io"
-	"syscall"
-)
+import "syscall"
 
 const (
 	// Registry key security and access rights.
@@ -90,20 +87,13 @@ func OpenKey(k Key, path string, access uint32) (Key, error) {
 }
 
 // ReadSubKeyNames returns the names of subkeys of key k.
-// The parameter n controls the number of returned names,
-// analogous to the way os.File.Readdirnames works.
-func (k Key) ReadSubKeyNames(n int) ([]string, error) {
+func (k Key) ReadSubKeyNames() ([]string, error) {
 	names := make([]string, 0)
 	// Registry key size limit is 255 bytes and described there:
 	// https://msdn.microsoft.com/library/windows/desktop/ms724872.aspx
 	buf := make([]uint16, 256) //plus extra room for terminating zero byte
 loopItems:
 	for i := uint32(0); ; i++ {
-		if n > 0 {
-			if len(names) == n {
-				return names, nil
-			}
-		}
 		l := uint32(len(buf))
 		for {
 			err := syscall.RegEnumKeyEx(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
@@ -123,9 +113,6 @@ loopItems:
 		}
 		names = append(names, syscall.UTF16ToString(buf[:l]))
 	}
-	if n > len(names) {
-		return names, io.EOF
-	}
 	return names, nil
 }
 
diff --git a/src/internal/syscall/windows/registry/registry_test.go b/src/internal/syscall/windows/registry/registry_test.go
index 8227232c70..5797162900 100644
--- a/src/internal/syscall/windows/registry/registry_test.go
+++ b/src/internal/syscall/windows/registry/registry_test.go
@@ -34,7 +34,7 @@ func TestReadSubKeyNames(t *testing.T) {
 	}
 	defer k.Close()
 
-	names, err := k.ReadSubKeyNames(-1)
+	names, err := k.ReadSubKeyNames()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -190,7 +190,7 @@ func setValues(t *testing.T, k registry.Key) {
 }
 
 func enumerateValues(t *testing.T, k registry.Key) {
-	names, err := k.ReadValueNames(-1)
+	names, err := k.ReadValueNames()
 	if err != nil {
 		t.Error(err)
 		return
@@ -480,7 +480,7 @@ func deleteValues(t *testing.T, k registry.Key) {
 			continue
 		}
 	}
-	names, err := k.ReadValueNames(-1)
+	names, err := k.ReadValueNames()
 	if err != nil {
 		t.Error(err)
 		return
diff --git a/src/internal/syscall/windows/registry/value.go b/src/internal/syscall/windows/registry/value.go
index bf8ab00759..dc3930a6bc 100644
--- a/src/internal/syscall/windows/registry/value.go
+++ b/src/internal/syscall/windows/registry/value.go
@@ -8,7 +8,6 @@ package registry
 
 import (
 	"errors"
-	"io"
 	"syscall"
 	"unicode/utf16"
 	"unsafe"
@@ -341,9 +340,7 @@ func (k Key) DeleteValue(name string) error {
 }
 
 // ReadValueNames returns the value names of key k.
-// The parameter n controls the number of returned names,
-// analogous to the way os.File.Readdirnames works.
-func (k Key) ReadValueNames(n int) ([]string, error) {
+func (k Key) ReadValueNames() ([]string, error) {
 	ki, err := k.Stat()
 	if err != nil {
 		return nil, err
@@ -352,11 +349,6 @@ func (k Key) ReadValueNames(n int) ([]string, error) {
 	buf := make([]uint16, ki.MaxValueNameLen+1) // extra room for terminating null character
 loopItems:
 	for i := uint32(0); ; i++ {
-		if n > 0 {
-			if len(names) == n {
-				return names, nil
-			}
-		}
 		l := uint32(len(buf))
 		for {
 			err := regEnumValue(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
@@ -376,8 +368,5 @@ loopItems:
 		}
 		names = append(names, syscall.UTF16ToString(buf[:l]))
 	}
-	if n > len(names) {
-		return names, io.EOF
-	}
 	return names, nil
 }