Fix local copy path for `kubectl cp'.

Adds an extra check condition for "." in stripPathShortcuts
so that an empty string is returned, and the correct prefix
index is used untarAll when generating path names.

Resolves: #69804.

pkg/kubectl/cmd/cp/cp.go

@@ -310,8 +310,8 @@ func stripPathShortcuts(p string) string {
 		trimmed = strings.TrimPrefix(newPath, "../")
 	}
 
-	// trim leftover ".."
-	if newPath == ".." {
+	// trim leftover {".", ".."}
+	if (newPath == "." || newPath == "..") {
 		newPath = ""
 	}
 

pkg/kubectl/cmd/cp/cp_test.go

@@ -173,6 +173,11 @@ func TestStripPathShortcuts(t *testing.T) {
 			input:    "...foo",
 			expected: "...foo",
 		},
+		{
+			name:     "test root directory",
+			input:    "/",
+			expected: "",
+		},
 	}
 
 	for _, test := range tests {