5 files changed, 128 insertions, 17 deletions
diff --git a/libgo/go/os/file_unix.go b/libgo/go/os/file_unix.go
index 5f7ab30..912ba5a 100644
--- a/libgo/go/os/file_unix.go
+++ b/libgo/go/os/file_unix.go
@@ -192,6 +192,7 @@ func epipecheck(file *File, e error) {
 const DevNull = "/dev/null"
 
 // openFileNolog is the Unix implementation of OpenFile.
+// Changes here should be reflected in openFdAt, if relevant.
 func openFileNolog(name string, flag int, perm FileMode) (*File, error) {
 	setSticky := false
 	if !supportsCreateWithStickyBit && flag&O_CREATE != 0 && perm&ModeSticky != 0 {
diff --git a/libgo/go/os/path.go b/libgo/go/os/path.go
index 30cc6c8..104b7ce 100644
--- a/libgo/go/os/path.go
+++ b/libgo/go/os/path.go
@@ -58,6 +58,14 @@ func MkdirAll(path string, perm FileMode) error {
 	return nil
 }
 
+// RemoveAll removes path and any children it contains.
+// It removes everything it can but returns the first error
+// it encounters. If the path does not exist, RemoveAll
+// returns nil (no error).
+func RemoveAll(path string) error {
+	return removeAll(path)
+}
+
 // endsWithDot reports whether the final component of path is ".".
 func endsWithDot(path string) bool {
 	if path == "." {
diff --git a/libgo/go/os/removeall_at.go b/libgo/go/os/removeall_at.go
index 5128de7..d1210ee 100644
--- a/libgo/go/os/removeall_at.go
+++ b/libgo/go/os/removeall_at.go
@@ -9,10 +9,11 @@ package os
 import (
 	"internal/syscall/unix"
 	"io"
+	"runtime"
 	"syscall"
 )
 
-func RemoveAll(path string) error {
+func removeAll(path string) error {
 	if path == "" {
 		// fail silently to retain compatibility with previous behavior
 		// of RemoveAll. See issue 28830.
@@ -56,8 +57,13 @@ func removeAllFrom(parent *File, path string) error {
 		return nil
 	}
 
-	// If not a "is directory" error, we have a problem
-	if err != syscall.EISDIR && err != syscall.EPERM {
+	// EISDIR means that we have a directory, and we need to
+	// remove its contents.
+	// EPERM or EACCES means that we don't have write permission on
+	// the parent directory, but this entry might still be a directory
+	// whose contents need to be removed.
+	// Otherwise just return the error.
+	if err != syscall.EISDIR && err != syscall.EPERM && err != syscall.EACCES {
 		return err
 	}
 
@@ -68,11 +74,11 @@ func removeAllFrom(parent *File, path string) error {
 		return statErr
 	}
 	if statInfo.Mode&syscall.S_IFMT != syscall.S_IFDIR {
-		// Not a directory; return the error from the Remove
+		// Not a directory; return the error from the Remove.
 		return err
 	}
 
-	// Remove the directory's entries
+	// Remove the directory's entries.
 	var recurseErr error
 	for {
 		const request = 1024
@@ -87,7 +93,7 @@ func removeAllFrom(parent *File, path string) error {
 		}
 
 		names, readErr := file.Readdirnames(request)
-		// Errors other than EOF should stop us from continuing
+		// Errors other than EOF should stop us from continuing.
 		if readErr != nil && readErr != io.EOF {
 			file.Close()
 			if IsNotExist(readErr) {
@@ -116,7 +122,7 @@ func removeAllFrom(parent *File, path string) error {
 		}
 	}
 
-	// Remove the directory itself
+	// Remove the directory itself.
 	unlinkError := unix.Unlinkat(parentFd, path, unix.AT_REMOVEDIR)
 	if unlinkError == nil || IsNotExist(unlinkError) {
 		return nil
@@ -128,11 +134,31 @@ func removeAllFrom(parent *File, path string) error {
 	return unlinkError
 }
 
-func openFdAt(fd int, path string) (*File, error) {
-	fd, err := unix.Openat(fd, path, O_RDONLY, 0)
-	if err != nil {
-		return nil, err
+// openFdAt opens path relative to the directory in fd.
+// Other than that this should act like openFileNolog.
+// This acts like openFileNolog rather than OpenFile because
+// we are going to (try to) remove the file.
+// The contents of this file are not relevant for test caching.
+func openFdAt(dirfd int, name string) (*File, error) {
+	var r int
+	for {
+		var e error
+		r, e = unix.Openat(dirfd, name, O_RDONLY, 0)
+		if e == nil {
+			break
+		}
+
+		// See comment in openFileNolog.
+		if runtime.GOOS == "darwin" && e == syscall.EINTR {
+			continue
+		}
+
+		return nil, &PathError{"openat", name, e}
+	}
+
+	if !supportsCloseOnExec {
+		syscall.CloseOnExec(r)
 	}
 
-	return NewFile(uintptr(fd), path), nil
+	return newFile(uintptr(r), name, kindOpenFile), nil
 }
diff --git a/libgo/go/os/removeall_noat.go b/libgo/go/os/removeall_noat.go
index 47fff42..7d9f73e 100644
--- a/libgo/go/os/removeall_noat.go
+++ b/libgo/go/os/removeall_noat.go
@@ -11,11 +11,7 @@ import (
 	"syscall"
 )
 
-// RemoveAll removes path and any children it contains.
-// It removes everything it can but returns the first error
-// it encounters. If the path does not exist, RemoveAll
-// returns nil (no error).
-func RemoveAll(path string) error {
+func removeAll(path string) error {
 	if path == "" {
 		// fail silently to retain compatibility with previous behavior
 		// of RemoveAll. See issue 28830.
diff --git a/libgo/go/os/removeall_test.go b/libgo/go/os/removeall_test.go
index 0f7dce0..9dab0d4 100644
--- a/libgo/go/os/removeall_test.go
+++ b/libgo/go/os/removeall_test.go
@@ -292,3 +292,83 @@ func TestRemoveReadOnlyDir(t *testing.T) {
 		t.Error("subdirectory was not removed")
 	}
 }
+
+// Issue #29983.
+func TestRemoveAllButReadOnly(t *testing.T) {
+	switch runtime.GOOS {
+	case "nacl", "js", "windows":
+		t.Skipf("skipping test on %s", runtime.GOOS)
+	}
+
+	if Getuid() == 0 {
+		t.Skip("skipping test when running as root")
+	}
+
+	t.Parallel()
+
+	tempDir, err := ioutil.TempDir("", "TestRemoveAllButReadOnly-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer RemoveAll(tempDir)
+
+	dirs := []string{
+		"a",
+		"a/x",
+		"a/x/1",
+		"b",
+		"b/y",
+		"b/y/2",
+		"c",
+		"c/z",
+		"c/z/3",
+	}
+	readonly := []string{
+		"b",
+	}
+	inReadonly := func(d string) bool {
+		for _, ro := range readonly {
+			if d == ro {
+				return true
+			}
+			dd, _ := filepath.Split(d)
+			if filepath.Clean(dd) == ro {
+				return true
+			}
+		}
+		return false
+	}
+
+	for _, dir := range dirs {
+		if err := Mkdir(filepath.Join(tempDir, dir), 0777); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, dir := range readonly {
+		d := filepath.Join(tempDir, dir)
+		if err := Chmod(d, 0555); err != nil {
+			t.Fatal(err)
+		}
+
+		// Defer changing the mode back so that the deferred
+		// RemoveAll(tempDir) can succeed.
+		defer Chmod(d, 0777)
+	}
+
+	if err := RemoveAll(tempDir); err == nil {
+		t.Fatal("RemoveAll succeeded unexpectedly")
+	}
+
+	for _, dir := range dirs {
+		_, err := Stat(filepath.Join(tempDir, dir))
+		if inReadonly(dir) {
+			if err != nil {
+				t.Errorf("file %q was deleted but should still exist", dir)
+			}
+		} else {
+			if err == nil {
+				t.Errorf("file %q still exists but should have been deleted", dir)
+			}
+		}
+	}
+}