path/filepath: replace os.MkdirTemp with T.TempDir

Add the tempDirCanonical function, for tests that need a temporary
directory that does not contain symlinks.

Updates #45402

Change-Id: I3d08ef32ef911331544acce3d7d013b4c3382960
Reviewed-on: https://go-review.googlesource.com/c/go/+/308011
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
index bb6bc0dd87..cd107b6c85 100644
--- a/src/path/filepath/path_test.go
+++ b/src/path/filepath/path_test.go
@@ -449,6 +449,19 @@ func chtmpdir(t *testing.T) (restore func()) {
 	}
 }
 
+// tempDirCanonical returns a temporary directory for the test to use, ensuring
+// that the returned path does not contain symlinks.
+func tempDirCanonical(t *testing.T) string {
+	dir := t.TempDir()
+
+	cdir, err := filepath.EvalSymlinks(dir)
+	if err != nil {
+		t.Errorf("tempDirCanonical: %v", err)
+	}
+
+	return cdir
+}
+
 func TestWalk(t *testing.T) {
 	walk := func(root string, fn fs.WalkDirFunc) error {
 		return filepath.Walk(root, func(path string, info fs.FileInfo, err error) error {