os: don't use T.Cleanup in TestRemoveAllLongPath

Revert CL 306290 changes to TestRemoveAllLongPath. This breaks the test
on aix, illumos and solaris. We need to chdir out of startPath before
attempting to remove it.

Updates #45182

Change-Id: Ic14fa1962d6f2cc83238f6fc2c6932fd9a6e52a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/307189
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>

src/os/os_windows_test.go

@@ -29,6 +29,25 @@ import (
 // For TestRawConnReadWrite.
 type syscallDescriptor = syscall.Handle
 
+// chdir changes the current working directory to the named directory,
+// and then restore the original working directory at the end of the test.
+func chdir(t *testing.T, dir string) {
+	olddir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("chdir: %v", err)
+	}
+	if err := os.Chdir(dir); err != nil {
+		t.Fatalf("chdir %s: %v", dir, err)
+	}
+
+	t.Cleanup(func() {
+		if err := os.Chdir(olddir); err != nil {
+			t.Errorf("chdir to original working directory %s: %v", olddir, err)
+			os.Exit(1)
+		}
+	})
+}
+
 func TestSameWindowsFile(t *testing.T) {
 	temp, err := os.MkdirTemp("", "TestSameWindowsFile")
 	if err != nil {

src/os/removeall_test.go

@@ -156,25 +156,6 @@ func TestRemoveAllLarge(t *testing.T) {
 	}
 }
 
-// chdir changes the current working directory to the named directory,
-// and then restore the original working directory at the end of the test.
-func chdir(t *testing.T, dir string) {
-	olddir, err := os.Getwd()
-	if err != nil {
-		t.Fatalf("chdir: %v", err)
-	}
-	if err := os.Chdir(dir); err != nil {
-		t.Fatalf("chdir %s: %v", dir, err)
-	}
-
-	t.Cleanup(func() {
-		if err := os.Chdir(olddir); err != nil {
-			t.Errorf("chdir to original working directory %s: %v", olddir, err)
-			os.Exit(1)
-		}
-	})
-}
-
 func TestRemoveAllLongPath(t *testing.T) {
 	switch runtime.GOOS {
 	case "aix", "darwin", "ios", "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "illumos", "solaris":
@@ -183,12 +164,21 @@ func TestRemoveAllLongPath(t *testing.T) {
 		t.Skip("skipping for not implemented platforms")
 	}
 
+	prevDir, err := Getwd()
+	if err != nil {
+		t.Fatalf("Could not get wd: %s", err)
+	}
+
 	startPath, err := os.MkdirTemp("", "TestRemoveAllLongPath-")
 	if err != nil {
 		t.Fatalf("Could not create TempDir: %s", err)
 	}
 	defer RemoveAll(startPath)
-	chdir(t, startPath)
+
+	err = Chdir(startPath)
+	if err != nil {
+		t.Fatalf("Could not chdir %s: %s", startPath, err)
+	}
 
 	// Removing paths with over 4096 chars commonly fails
 	for i := 0; i < 41; i++ {
@@ -205,6 +195,11 @@ func TestRemoveAllLongPath(t *testing.T) {
 		}
 	}
 
+	err = Chdir(prevDir)
+	if err != nil {
+		t.Fatalf("Could not chdir %s: %s", prevDir, err)
+	}
+
 	err = RemoveAll(startPath)
 	if err != nil {
 		t.Errorf("RemoveAll could not remove long file path %s: %s", startPath, err)